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author | kinitrupti | 2017-05-12 18:40:35 +0530 |
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committer | kinitrupti | 2017-05-12 18:40:35 +0530 |
commit | 64d949698432e05f2a372d9edc859c5b9df1f438 (patch) | |
tree | 012fd5b4ac9102cdcf5bc56305e49d6714fa5951 /Introduction_to_Heat_Transfer_by_S._K._Som | |
parent | 9c6ab8cbf3e1a84c780386abf4852d84cdd32d56 (diff) | |
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Revised list of TBCs
Diffstat (limited to 'Introduction_to_Heat_Transfer_by_S._K._Som')
22 files changed, 1270 insertions, 7963 deletions
diff --git a/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter1.ipynb b/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter1.ipynb index d3b728b1..d9d7f745 100644 --- a/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter1.ipynb +++ b/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter1.ipynb @@ -18,7 +18,7 @@ }, { "cell_type": "code", - "execution_count": 1, + "execution_count": 4, "metadata": { "collapsed": false }, @@ -34,6 +34,7 @@ } ], "source": [ + "import math\n", "print\"Introduction to heat transfer by S.K.Som, Chapter 1, Example 1\"\n", "#The temprature of two faces of the slabs are T1=40°C & T2=20°C \n", "#The thickness of the slab(L) is 80mm or .08m\n", @@ -57,7 +58,7 @@ }, { "cell_type": "code", - "execution_count": 3, + "execution_count": 5, "metadata": { "collapsed": false }, @@ -73,7 +74,7 @@ } ], "source": [ - "\n", + "import math\n", "print\"Introduction to heat transfer by S.K.Som, Chapter 1, Example 2\"\n", "#The thermal conductivity(km)of masonry wall is .8 W/(mK)\n", "#The thermal conductivity(kc)of composite wall is .2 W/(mK)\n", @@ -88,7 +89,7 @@ "#The thickness of masonry wall is Lm.\n", "print\"The thickness of masonry wall is Lm in m\"\n", "Lm=(km/kc)*(Lc/(0.8))\n", - "print\"Lm=\",Lm" + "print\"Lm=\",Lm\n" ] }, { @@ -100,7 +101,7 @@ }, { "cell_type": "code", - "execution_count": 5, + "execution_count": 6, "metadata": { "collapsed": false }, @@ -116,7 +117,7 @@ } ], "source": [ - "\n", + "import math\n", "print\"Introduction to heat transfer by S.K.Som, Chapter 1, Example 4\"\n", "#The average forced convective heat transfer coefficient(hbr) is 200 W/( m**2 °C)\n", "#The fluid temprature(Tinf) upstream of the cold surface is 100°C\n", @@ -139,7 +140,7 @@ }, { "cell_type": "code", - "execution_count": 6, + "execution_count": 7, "metadata": { "collapsed": false }, @@ -155,7 +156,7 @@ } ], "source": [ - "\n", + "import math\n", "print\"Introduction to heat transfer by S.K.Som, Chapter 1, Example 5\"\n", "#The average heat transfer coefficient(hbr) is 800 W/(m**2°C)\n", "#The surface temprature of heat exchanger is 75°C and air temprature is 25°C so deltaT=(75-25)\n", @@ -178,7 +179,7 @@ }, { "cell_type": "code", - "execution_count": 14, + "execution_count": 3, "metadata": { "collapsed": false }, @@ -189,16 +190,16 @@ "text": [ "Introduction to heat transfer by S.K.Som, Chapter 1, Example 6\n", "The rate of heat transfer from the plate is given by Q=hbr*A*(Ts-Tinf)\n", - "Q= 224.0\n", + "Equating the above two equations we get hbr=(m*cp*|dT/dt|)/(A*(Ts-Tinf)) in W/(m**2°C)\n", + "hbr= 11.2\n", "The rate of heat transfer can also be written in the form of Q=m*cp*|dT/dt| from an energy balance.\n", "Q= 224.0\n", - "Equating the above two equations we get hbr=(m*cp*|dT/dt|)/(A*(Ts-Tinf)) in W/(m**2°C)\n", - "hbr= 11.2\n" + "Equating the above two equations we get hbr=(m*cp*|dT/dt|)/(A*(Ts-Tinf)) in W/(m**2°C)\n" ] } ], "source": [ - "\n", + "import math\n", "print\"Introduction to heat transfer by S.K.Som, Chapter 1, Example 6\"\n", "#The temprature of the plate(Ts) is 225°C\n", "#The ambient temprature (Tinf) is 25°C\n", @@ -214,13 +215,28 @@ "m=4;\n", "cp=2.8;\n", "print\"The rate of heat transfer from the plate is given by Q=hbr*A*(Ts-Tinf)\"\n", + "print\"Equating the above two equations we get hbr=(m*cp*|dT/dt|)/(A*(Ts-Tinf)) in W/(m**2°C)\"\n", + "hbr=(m*cp*10**3*X)/(A*(Ts-Tinf))\n", + "print\"hbr=\",hbr\n", "Q=hbr*A*(Ts-Tinf)\n", - "print\"Q=\",Q\n", "print\"The rate of heat transfer can also be written in the form of Q=m*cp*|dT/dt| from an energy balance.\"\n", "print\"Q=\",Q\n", "print\"Equating the above two equations we get hbr=(m*cp*|dT/dt|)/(A*(Ts-Tinf)) in W/(m**2°C)\"\n", - "hbr=(m*cp*10**3*X)/(A*(Ts-Tinf))\n", - "print\"hbr=\",hbr" + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n" ] }, { @@ -232,7 +248,7 @@ }, { "cell_type": "code", - "execution_count": 2, + "execution_count": 8, "metadata": { "collapsed": false }, @@ -248,7 +264,7 @@ } ], "source": [ - "\n", + "import math\n", "print\"Introduction to heat transfer by S.K.Som, Chapter 1, Example 7\"\n", "#The temprature(T) of brick wall after sunset is 50°C\n", "#The emissity value(emi)=0.9\n", @@ -272,7 +288,7 @@ }, { "cell_type": "code", - "execution_count": 4, + "execution_count": 9, "metadata": { "collapsed": false }, @@ -288,7 +304,7 @@ } ], "source": [ - "\n", + "import math\n", "print\"Introduction to heat transfer by S.K.Som, Chapter 1, Example 8\"\n", "#The temprature(T) of asphalt pavement = 50°C\n", "#The stefan-Boltzman constant(sigma)=5.6697*10**-8 W/(m**2*K**4).\n", @@ -298,7 +314,7 @@ "print\"The emitted radiant energy per unit surface area is given by Eb/A=sigma*T**4 in W/m**2\"\n", "#Let Eb/A=F\n", "F=sigma*(50+273.15)**4\n", - "print\"F=\",F" + "print\"F=\",F\n" ] }, { @@ -310,7 +326,7 @@ }, { "cell_type": "code", - "execution_count": 4, + "execution_count": 10, "metadata": { "collapsed": false }, @@ -330,7 +346,7 @@ } ], "source": [ - "\n", + "import math\n", "print\"Introduction to heat transfer by S.K.Som, Chapter 1, Example 9\"\n", "#The Thickness(L) of wall= 150 mm or 0.15 m.\n", "#The wall on one side is exposed to air at temprature(Ta)= 60°C and on the other side to air at temprature(Tb) = 20°C\n", @@ -367,7 +383,7 @@ }, { "cell_type": "code", - "execution_count": 19, + "execution_count": 11, "metadata": { "collapsed": false }, @@ -378,9 +394,7 @@ "text": [ "Introduction to heat transfer by S.K.Som, Chapter 1, Example 10\n", "Heat transfer from the outer surface takes place only by radiation is given by Q/A=F1=emi*sigma*(T2**4-T0**4)in W/m**2 for different values of tempratures in K\n", - "F1= 332.029390022\n", "heat transfer from the outer surface can also be written as Q/A=F2=(Ti-To)/((1/hbri)+(L/k)+(1/hr)) in W/m**2 at different tempratures in K\n", - "F2= 332.132667923\n", "The values of temprature that are considered are <298 K\n", "Satisfactory solutions for Temprature in K is\n", "T2= 292.5\n", @@ -391,7 +405,7 @@ } ], "source": [ - "\n", + "import math\n", "print\"Introduction to heat transfer by S.K.Som, Chapter 1, Example 10\"\n", "#The spacecraft panel has thickness(L)=.01 m\n", "#The spacecraft has inner temprature (Ti)=298 K\n", @@ -413,9 +427,7 @@ "#Radiation heat transfer coefficient(hr) is defined as Q/A=hr(T2-To)\n", "#so hr=4.536*10**-8*T2**3\n", "print\"Heat transfer from the outer surface takes place only by radiation is given by Q/A=F1=emi*sigma*(T2**4-T0**4)in W/m**2 for different values of tempratures in K\"\n", - "print\"F1=\",F1\n", "print\"heat transfer from the outer surface can also be written as Q/A=F2=(Ti-To)/((1/hbri)+(L/k)+(1/hr)) in W/m**2 at different tempratures in K\"\n", - "print\"F2=\",F2\n", "print\"The values of temprature that are considered are <298 K\"\n", "for i in range(285,292):\n", " T2=i\n", @@ -445,7 +457,7 @@ }, { "cell_type": "code", - "execution_count": 2, + "execution_count": 12, "metadata": { "collapsed": false }, @@ -488,7 +500,8 @@ "print\"The total heat loss by The pipe per unit length is given by Q/L=hbr*A*(T1-T2)+sigma*emi*A*(T1**4-T2**4) in W/m\"\n", "#Let Q/L=F\n", "F=hbr*A*((T1+273.15)-(T2+273.15))+sigma*emi*A*((T1+273.15)**4-(T2+273.15)**4)\n", - "print\"F=\",F" + "print\"F=\",F\n", + "\n" ] } ], diff --git a/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter10.ipynb b/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter10.ipynb index 9eacc4ed..95f29d79 100644 --- a/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter10.ipynb +++ b/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter10.ipynb @@ -44,6 +44,10 @@ } ], "source": [ + " \n", + " \n", + " \n", + " \n", "import math\n", " \n", "print\"Introduction to heat transfer by S.K.Som, Chapter 10, Example 1\"\n", @@ -90,7 +94,29 @@ "print\"LMTD=\",LMTD\n", "print\"Area(A)=Q/(U*LMTD) in m**2\"\n", "A=Q/(U*LMTD)\n", - "print\"A=\",A" + "print\"A=\",A\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n" ] }, { @@ -124,6 +150,10 @@ } ], "source": [ + " \n", + " \n", + " \n", + " \n", "import math\n", " \n", "print\"Introduction to heat transfer by S.K.Som, Chapter 10, Example 2\"\n", @@ -163,7 +193,7 @@ "#Area(A)=Q/(U*LMTD) in m**2\n", "print\"Area(A)=Q/(U*LMTD) in m**2\"\n", "A=Q/(U*LMTD)\n", - "print\"A=\",A" + "print\"A=\",A\n" ] }, { @@ -203,6 +233,10 @@ } ], "source": [ + " \n", + " \n", + " \n", + " \n", "import math\n", " \n", "print\"Introduction to heat transfer by S.K.Som, Chapter 10, Example 3\"\n", @@ -250,7 +284,13 @@ "#overall heat transfer coefficient(U)=Q/(A*F*LMTD)\n", "print\"overall heat transfer coefficient(U)=Q/(A*F*LMTD)in W/(m**2*K)\"\n", "U=Q/(A*F*LMTD)\n", - "print\"U=\",U" + "print\"U=\",U\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n" ] }, { @@ -302,6 +342,10 @@ } ], "source": [ + " \n", + " \n", + " \n", + " \n", "import math\n", " \n", "print\"Introduction to heat transfer by S.K.Som, Chapter 10, Example 5\"\n", @@ -380,7 +424,33 @@ "print\"To provide this surface area ,The length(L) of the tube required is given by L=A/(pi*D) in m\"\n", "L=A/(math.pi*D)\n", "print\"Hence same result is obtained for both methods\"\n", - "print\"L=\",L" + "print\"L=\",L\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n" ] }, { @@ -412,6 +482,10 @@ } ], "source": [ + " \n", + " \n", + " \n", + " \n", "import math\n", " \n", "print\"Introduction to heat transfer by S.K.Som, Chapter 10, Example 6\"\n", @@ -446,7 +520,13 @@ "#Hence The total heat transfer rate (Q)=eff*Cmin*(Thi-Tci)in kW.\n", "print\"The total heat transfer rate (Q)=eff*Cmin*(Thi-Tci) in kW\" \n", "Q=eff*Cmin*(Thi-Tci)\n", - "print\"Q=\",Q" + "print\"Q=\",Q\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n" ] }, { @@ -480,6 +560,10 @@ } ], "source": [ + " \n", + " \n", + " \n", + " \n", "import math\n", " \n", "print\"Introduction to heat transfer by S.K.Som, Chapter 10, Example 7\"\n", @@ -519,7 +603,22 @@ "#The exit temprature(Tho) of air is given by Thi-(Q/(mdota*cpa))\n", "print\"The exit temprature of air in °C \"\n", "Tho=Thi-(Q/(mdota*1000*cpa))#NOTE:-The answer slightly varies from the answer in book(i.e Tho=26°C) because the value of Q taken in book is approximated to 1*10**6W.\n", - "print\"Tho=\",Tho" + "print\"Tho=\",Tho\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n" ] }, { @@ -557,6 +656,10 @@ } ], "source": [ + " \n", + " \n", + " \n", + " \n", "import math\n", " \n", "print\"Introduction to heat transfer by S.K.Som, Chapter 10, Example 8\"\n", @@ -599,7 +702,28 @@ "Tho=Tci;\n", "print\"Effectiveness of heat exchanger is \"\n", "eff=(mdoth*ch*(Thi-Tho))/(mdoth*ch*(Thi-Tci))\n", - "print\"eff=\",eff" + "print\"eff=\",eff\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n" ] } ], diff --git a/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter10_ljUjU8j.ipynb b/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter10_ljUjU8j.ipynb deleted file mode 100644 index 95f29d79..00000000 --- a/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter10_ljUjU8j.ipynb +++ /dev/null @@ -1,751 +0,0 @@ -{ - "cells": [ - { - "cell_type": "markdown", - "metadata": { - "collapsed": true - }, - "source": [ - "# Chapter 10:Principles of heat exchangers" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex10.1:pg-415" - ] - }, - { - "cell_type": "code", - "execution_count": 1, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 10, Example 1\n", - "The rate of heat transfer from water is given by Q=mdot*cp*(T3-T4) in W\n", - "Q= 11286.0\n", - "(a) For a parallel flow arrangement\n", - "LMTD is given by (deltaT2-deltaT1)/(ln(deltaT2/deltaT1)) in °C \n", - "LMTD= 35.4699026617\n", - "Area(A)=Q/(U*LMTD) in m**2\n", - "A= 0.397731567932\n", - "(b)For counterflow arrangement\n", - "LMTD=(deltaT2-deltaT1)/(ln(deltaT2/deltaT1))in°C \n", - "LMTD= 36.3143018164\n", - "Area(A)=Q/(U*LMTD) in m**2\n", - "A= 0.38848330532\n" - ] - } - ], - "source": [ - " \n", - " \n", - " \n", - " \n", - "import math\n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 10, Example 1\"\n", - "#A brine solution is heated from temprature ,T1=8°C to temprature,T2=14°C in a double pipe heat exchanger.\n", - "T1=8.0;\n", - "T2=14.0;\n", - "#Water entering at temprature T3=55°C and leaving at temprature,T4=40°C at the mass flow rate of (mdot)=0.18kg/s\n", - "mdot=0.18;\n", - "T3=55.0;\n", - "T4=40.0;\n", - "#Specific heat (cp) of water =4.18kJ/(kg*K)\n", - "cp=4.18*10**3;\n", - "#overall heat transfer coefficient(U)=800 W/(m**2*K)\n", - "U=800.0;\n", - "#The rate of heat transfer from water is given by Q=mdot*cp*(T3-T4)\n", - "print\"The rate of heat transfer from water is given by Q=mdot*cp*(T3-T4) in W\"\n", - "Q=mdot*cp*(T3-T4)\n", - "print\"Q=\",Q\n", - "print\"(a) For a parallel flow arrangement\"\n", - "#For a parallel flow arrangement deltaT1=T3-T1 and deltaT2=T4-T2. \n", - "deltaT1=T3-T1;#deltaT1 is temprature difference \n", - "deltaT2=T4-T2;#deltaT2 is temprature difference \n", - "#LMTD(math.log mean temprature difference) is defined as (deltaT2-deltaT1)/(ln(deltaT2/deltaT1)) for both parallel and counter flow.\n", - "print\"LMTD is given by (deltaT2-deltaT1)/(ln(deltaT2/deltaT1)) in °C \"\n", - "#let X=math.log10((deltaT2/deltaT1)) and Y=math.log10(2.718281)\n", - "X=math.log10((deltaT2/deltaT1));\n", - "Y=math.log10(2.718281);\n", - "#ln=(ln(deltaT2/deltaT1))\n", - "ln=X/Y;\n", - "LMTD=(deltaT2-deltaT1)/ln\n", - "print\"LMTD=\",LMTD\n", - "#Area(A)=Q/(U*LMTD) in m**2\n", - "print\"Area(A)=Q/(U*LMTD) in m**2\"\n", - "A=Q/(U*LMTD)\n", - "print\"A=\",A\n", - "print\"(b)For counterflow arrangement\"\n", - "deltaT1=T3-T2;\n", - "deltaT2=T4-T1;\n", - "print\"LMTD=(deltaT2-deltaT1)/(ln(deltaT2/deltaT1))in°C \"\n", - "X=math.log10((deltaT2/deltaT1));\n", - "Y=math.log10(2.718281);\n", - "ln=X/Y;\n", - "LMTD=(deltaT2-deltaT1)/ln\n", - "print\"LMTD=\",LMTD\n", - "print\"Area(A)=Q/(U*LMTD) in m**2\"\n", - "A=Q/(U*LMTD)\n", - "print\"A=\",A\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex10.2:pg-416" - ] - }, - { - "cell_type": "code", - "execution_count": 3, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 10, Example 2\n", - "The inlet temprature(Tc1) of cold oil in °C \n", - "Tc1= 55.0948103792\n", - "The rate of heat transfer Q=mdoth*ch*(Th1-Th2) in W\n", - "Q= 190190.0\n", - "LMTD is given by (deltaT2-deltaT1)/(ln(deltaT2/deltaT1)) in °C \n", - "LMTD= 28.996452611\n", - "Area(A)=Q/(U*LMTD) in m**2\n", - "A= 10.0908895279\n" - ] - } - ], - "source": [ - " \n", - " \n", - " \n", - " \n", - "import math\n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 10, Example 2\"\n", - "#Hot oil(specific heat,ch=2.09kJ/(kg*K)) flows through counter flow heat excahnger at the mass flow rate of mdoth=(0.7kg/s)\n", - "ch=2.09*10**3;\n", - "mdoth=0.7;\n", - "#overall heat transfer coefficient(U)=650 W/(m**2*K)\n", - "U=650;\n", - "#It enters at temprature,Th1=200°C and leaves at temprature,Th2=70°C \n", - "Th1=200;\n", - "Th2=70;\n", - "#Cold oil(specific heat,cc=1.67kJ/(kg*K) exits at temprature,Tc2=150°C at the mass flow rate of mdotc=(1.2kg/s)\n", - "mdotc=1.2;\n", - "cc=1.67*10**3;\n", - "Tc2=150;\n", - "#The unknown inlet temprature(Tc1) of cold oil may be found from energy balance mdotc*(Tc2-Tc1)=mdoth*(Th2-Th1)\n", - "print\"The inlet temprature(Tc1) of cold oil in °C \"\n", - "Tc1=Tc2-((mdoth*ch)/(mdotc*cc))*(Th1-Th2)\n", - "print\"Tc1=\",Tc1\n", - "#The rate of heat transfer can be calculate as Q=mdoth*ch*(Th1-Th2)\n", - "print\"The rate of heat transfer Q=mdoth*ch*(Th1-Th2) in W\"\n", - "Q=mdoth*ch*(Th1-Th2)\n", - "deltaT1=Th1-Tc2;\n", - "print\"Q=\",Q\n", - "#deltaT1 is temprature difference between hot oil inlet temprature and cold oil exit temprature\n", - "deltaT2=Th2-Tc1;\n", - "#deltaT2 is temprature difference between hot oil exit temprature and cold oil inlet temprature\n", - "#LMTD(math.log mean temprature difference) is defined as (deltaT2-deltaT1)/(ln(deltaT2/deltaT1)) for counter flow.\n", - "print\"LMTD is given by (deltaT2-deltaT1)/(ln(deltaT2/deltaT1)) in °C \"\n", - "#let X=log10((deltaT2/deltaT1)) and Y=log10(2.718281)\n", - "X=math.log10((deltaT2/deltaT1));\n", - "Y=math.log10(2.718281);\n", - "#ln=(ln(deltaT2/deltaT1))\n", - "ln=X/Y;\n", - "LMTD=(deltaT2-deltaT1)/ln\n", - "print\"LMTD=\",LMTD\n", - "#Area(A)=Q/(U*LMTD) in m**2\n", - "print\"Area(A)=Q/(U*LMTD) in m**2\"\n", - "A=Q/(U*LMTD)\n", - "print\"A=\",A\n" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex10.3:pg-417" - ] - }, - { - "cell_type": "code", - "execution_count": 5, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 10, Example 3\n", - "The outlet temprature(Tho) of oil in °C \n", - "Tho= 70.6666666667\n", - "For a counterflow heat exchanger\n", - "deltaT1= 10\n", - "deltaT2= 20.6666666667\n", - "LMTD is given by (deltaT2-deltaT1)/(ln(deltaT2/deltaT1)) in °C \n", - "LMTD= 14.6936488511\n", - "dimensionless parameters P and R are\n", - "P= 0\n", - "R= 0.733333333333\n", - "correction factor(F) for the cross flow arrangement as obtained from graph of F vs Single Pass flow with fluids unmixed\n", - "Q= 167200.0\n", - "overall heat transfer coefficient(U)=Q/(A*F*LMTD)in W/(m**2*K)\n", - "U= 758.604399737\n" - ] - } - ], - "source": [ - " \n", - " \n", - " \n", - " \n", - "import math\n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 10, Example 3\"\n", - "#A cross flow heat exchanger with both fluids unmixed is used to heat water((specific heat,cc=4.18kJ/(kg*K)) from temprature Tci=50°C to Tco=90°C \n", - "#flowing at the mass flow rate of (mdotc)=1kg/s\n", - "Tci=50;\n", - "Tco=90;\n", - "cc=4.18*10**3;\n", - "mdotc=1;\n", - "#The hot engine oil has (specific heat,ch=1.9kJ/(kg*K)) flowing at the mass flow rate of mdoth=3kg/s enters at temprature Thi=100°C\n", - "mdoth=3;\n", - "Thi=100;\n", - "ch=1.9*10**3;\n", - "#The unknown outlet temprature(Tho) of oil may be found from energy balance mdotc*(Tco-Tci)=mdoth*(Tho-Thi)\n", - "print\"The outlet temprature(Tho) of oil in °C \"\n", - "Tho=Thi-((mdotc*cc)/(mdoth*ch))*(Tco-Tci)\n", - "print\"Tho=\",Tho\n", - "print\"For a counterflow heat exchanger\"\n", - "deltaT1=Thi-Tco;#deltaT1 is temprature difference \n", - "deltaT2=Tho-Tci;#deltaT2 is temprature difference \n", - "print\"deltaT1=\",deltaT1\n", - "print\"deltaT2=\",deltaT2\n", - "#LMTD(math.log mean temprature difference) is defined as (deltaT2-deltaT1)/(ln(deltaT2/deltaT1)) for counter flow.\n", - "print\"LMTD is given by (deltaT2-deltaT1)/(ln(deltaT2/deltaT1)) in °C \"\n", - "#let X=log10((deltaT2/deltaT1)) and Y=log10(2.718281)\n", - "X=math.log10((deltaT2/deltaT1));\n", - "Y=math.log10(2.718281);\n", - "ln=X/Y;\n", - "LMTD=(deltaT2-deltaT1)/ln\n", - "print\"LMTD=\",LMTD\n", - "#Area(A)=20m**2\n", - "A=20;\n", - "#We have to employ correction factor(F) for the cross flow arrangement.\n", - "#We evaluate dimensionless parameters P=(Tco-Tci)/(Thi-Tco) and R=(Thi-Tho)/(Tco-Tci).\n", - "print\"dimensionless parameters P and R are\"\n", - "P=(Tco-Tci)/(Thi-Tci)\n", - "R=(Thi-Tho)/(Tco-Tci)\n", - "print\"P=\",P\n", - "print\"R=\",R\n", - "print\"correction factor(F) for the cross flow arrangement as obtained from graph of F vs Single Pass flow with fluids unmixed\"\n", - "F=0.75\n", - "#The rate of heat transfer can be calculate as Q=mdoth*ch*(Th1-Th2)\n", - "Q=mdotc*cc*(Tco-Tci);\n", - "print\"Q=\",Q\n", - "#overall heat transfer coefficient(U)=Q/(A*F*LMTD)\n", - "print\"overall heat transfer coefficient(U)=Q/(A*F*LMTD)in W/(m**2*K)\"\n", - "U=Q/(A*F*LMTD)\n", - "print\"U=\",U\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex10.5:pg-419" - ] - }, - { - "cell_type": "code", - "execution_count": 7, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 10, Example 5\n", - "(a)Applying LMTD method\n", - "The rate of heat transfer Q=mdotw*cpw*(Tout-Tin) in W\n", - "Q= 300960.0\n", - "The unknown outlet temprature(Thout) of geothermal fluid in °C \n", - "Thout= 125.085846868\n", - "LMTD is given by (deltaT2-deltaT1)/(ln(deltaT2/deltaT1)) in °C \n", - "LMTD= 81.903612671\n", - "Area(A)=Q/(U*LMTD) in m**2\n", - "A= 6.12427197827\n", - "To provide this surface area ,The length(L) of the tube required is given by L=A/(pi*D) in m\n", - "L= 129.961087757\n", - "(b)Applying NTU method\n", - "The heat capacity rates are defined as Ch=mdoth*cph and Cc=mdotw*cpw in KW/°C\n", - "Ch= 8.62\n", - "Cc= 5.016\n", - "C=Cmin/Cmax\n", - "C= 0.581902552204\n", - "Heat transfer effectiveness is defined as eff=Q/(Cmin*(Thin-Tin))\n", - "eff= 0.461538461538\n", - "NTU is determined by NTU=(1/(C-1))*ln((eff-1)/(eff*C-1))\n", - "NTU= 0.732568418453\n", - "Area(A)=(NTU*Cmin)/U in m**2\n", - "A= 6.12427197827\n", - "To provide this surface area ,The length(L) of the tube required is given by L=A/(pi*D) in m\n", - "Hence same result is obtained for both methods\n", - "L= 129.961087757\n" - ] - } - ], - "source": [ - " \n", - " \n", - " \n", - " \n", - "import math\n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 10, Example 5\"\n", - "#Water is heated from temprature ,Tin=30°C to Tout=90°C in a counter flow double pipe heat exchanger.\n", - "Tin=30;\n", - "Tout=90;\n", - "#Water flows at a mass flow rate of mdotw=1.2kg/s\n", - "mdotw=1.2;\n", - "#The heating is accomplished by a geothermal fluid which enters the heat exchanger at temprature ,Thin=160°C at the mass flow rate of mdoth=2kg/s\n", - "mdoth=2;\n", - "Thin=160;\n", - "#The inner tube is thin walled having diameter(D)=15mm or 0.015m\n", - "D=0.015;\n", - "#overall heat transfer coefficient(U)=600 W/(m**2*K)\n", - "U=600;\n", - "#The specific heat of water and geothermal fluid is (cpw=4.18kJ/(kg*K))and(cph=4.31kJ/(kg*K)) respectively\n", - "cpw=4.18*10**3;\n", - "cph=4.31*10**3;\n", - "#The rate of heat transfer in heat exchanger can be calculate as Q=mdotw*cpw*(Tout-Tin)\n", - "print\"(a)Applying LMTD method\"\n", - "print\"The rate of heat transfer Q=mdotw*cpw*(Tout-Tin) in W\"\n", - "Q=mdotw*cpw*(Tout-Tin)\n", - "print\"Q=\",Q\n", - "#The unknown outlet temprature(Thout) of geothermal fluid may be found from energy balance mdotw*cpw*(Tout-Tin)=mdoth*cph*(Thin-Thout)\n", - "print\"The unknown outlet temprature(Thout) of geothermal fluid in °C \"\n", - "Thout=Thin-Q/(mdoth*cph)\n", - "print\"Thout=\",Thout\n", - "deltaT1=Thin-Tout;#Temprature difference between inlet temprature of hot fluid and outlet temprature of cold fluid\n", - "deltaT2=Thout-Tin;#Temprature difference between outlet temprature of hot fluid and inlet temprature of cold fluid\n", - "#LMTD is defined as (deltaT2-deltaT1)/(ln(deltaT2/deltaT1)) for counter flow.\n", - "print\"LMTD is given by (deltaT2-deltaT1)/(ln(deltaT2/deltaT1)) in °C \"\n", - "#let X=math.log10((deltaT2/deltaT1))and Y=math.log10(2.718281)\n", - "X=math.log10((deltaT2/deltaT1));\n", - "Y=math.log10(2.718281);\n", - "ln=X/Y;\n", - "LMTD=(deltaT2-deltaT1)/ln\n", - "print\"LMTD=\",LMTD\n", - "#Area(A)=Q/(U*LMTD) in m**2\n", - "print\"Area(A)=Q/(U*LMTD) in m**2\"\n", - "A=Q/(U*LMTD)\n", - "print\"A=\",A\n", - "print\"To provide this surface area ,The length(L) of the tube required is given by L=A/(pi*D) in m\"\n", - "L=A/(math.pi*D)\n", - "print\"L=\",L\n", - "print\"(b)Applying NTU method\"\n", - "#The heat capacity rates are defined as Ch=mdoth*cph and Cc=mdotw*cw in KW/°C\n", - "print\"The heat capacity rates are defined as Ch=mdoth*cph and Cc=mdotw*cpw in KW/°C\"\n", - "Ch=(mdoth*cph)/1000\n", - "Cc=(mdotw*cpw)/1000\n", - "print\"Ch=\",Ch\n", - "print\"Cc=\",Cc\n", - "#So Cmin=Cc and Cmax=Ch\n", - "Cmin=Cc;\n", - "Cmax=Ch;\n", - "#C is defined as Cmin/Cmax\n", - "print\"C=Cmin/Cmax\"\n", - "C=Cmin/Cmax\n", - "print\"C=\",C\n", - "#Heat transfer effectiveness is (eff)\n", - "print\"Heat transfer effectiveness is defined as eff=Q/(Cmin*(Thin-Tin))\"\n", - "eff=(Q/1000)/(Cmin*(Thin-Tin))\n", - "print\"eff=\",eff\n", - "print\"NTU is determined by NTU=(1/(C-1))*ln((eff-1)/(eff*C-1))\"\n", - "#let X=math.log10((eff-1)/(eff*C-1)) and Y=math.log10(2.718281)\n", - "X=math.log10((eff-1)/(eff*C-1));\n", - "Y=math.log10(2.718281);\n", - "#ln=ln((eff-1)/(eff*C-1))\n", - "ln=X/Y;\n", - "#NTU is Number of transfer units\n", - "NTU=(1/(C-1))*ln\n", - "print\"NTU=\",NTU\n", - "#NTU =U*A/Cmin\n", - "print\"Area(A)=(NTU*Cmin)/U in m**2\"\n", - "A=(NTU*Cmin*1000)/U\n", - "print\"A=\",A\n", - "print\"To provide this surface area ,The length(L) of the tube required is given by L=A/(pi*D) in m\"\n", - "L=A/(math.pi*D)\n", - "print\"Hence same result is obtained for both methods\"\n", - "print\"L=\",L\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex10.6:pg-422" - ] - }, - { - "cell_type": "code", - "execution_count": 8, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 10, Example 6\n", - "NTU is defined as (U*A)/Cmin \n", - "NTU= 1.86170212766\n", - "Heat transfer effectiveness(eff) is defined as (1-e**(-NTU*(1-C))/(1-C*e**(-NTU*(1-C))\n", - "eff= 0.683715054322\n", - "The total heat transfer rate (Q)=eff*Cmin*(Thi-Tci) in kW\n", - "Q= 163.886498521\n" - ] - } - ], - "source": [ - " \n", - " \n", - " \n", - " \n", - "import math\n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 10, Example 6\"\n", - "#Water having specific heat,cw=4.18kJ/(kg*K) enters a counterflow double pipe heat exchanger at temprature,Tci=35°C flowing at the mass flow rate of mdotw=0.8 kg/s.\n", - "cw=4.18;\n", - "mdotw=0.8;\n", - "Tci=35;\n", - "#It is heated by oil having specific heat,co=1.88kJ/(kg*K) flowing at the mass flow rate of mdoto=1.5 kg/s from an inlet temprature(Thi) of 120°C.\n", - "co=1.88;\n", - "mdoto=1.5;\n", - "Thi=120;\n", - "#For an area(A) of 15m**2 and an overall heat transfer coefficient(U) of 350W/(m**2*K).\n", - "A=15;\n", - "U=350;\n", - "#Cwater and Co are heat capacities for water and oil respectively\n", - "#Cwater=mdotw*cw and Co=mdoto*co\n", - "Cwater=mdotw*cw;\n", - "Co=mdoto*co;\n", - "#C=Cmin/Cmax\n", - "Cmin=min(Cwater,Co);\n", - "Cmax=max(Cwater,Co);\n", - "C=Cmin/Cmax;\n", - "#NTU is number of transfer units\n", - "#NTU=(U*A)/Cmin\n", - "print\"NTU is defined as (U*A)/Cmin \"\n", - "NTU=(U*A)/(Cmin*1000)\n", - "print\"NTU=\",NTU\n", - "#Heat transfer effectiveness(eff) is defined as (1-e**(-NTU*(1-C))/(1-C*e**(-NTU*(1-C))\n", - "print\"Heat transfer effectiveness(eff) is defined as (1-e**(-NTU*(1-C))/(1-C*e**(-NTU*(1-C))\"\n", - "eff=(1-math.e**(-NTU*(1-C)))/(1-C*math.e**(-NTU*(1-C)))\n", - "print\"eff=\",eff\n", - "#Hence The total heat transfer rate (Q)=eff*Cmin*(Thi-Tci)in kW.\n", - "print\"The total heat transfer rate (Q)=eff*Cmin*(Thi-Tci) in kW\" \n", - "Q=eff*Cmin*(Thi-Tci)\n", - "print\"Q=\",Q\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex10.7:pg-424 " - ] - }, - { - "cell_type": "code", - "execution_count": 9, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 10, Example 7\n", - "NTU is defined as (U*A)/Cmin \n", - "NTU= 5.44554455446\n", - "The effectiveness of heat exchanger is\n", - "eff= 9.98333889769\n", - "The total heat transfer rate(Q)=eff*Cmin*(Thi-Tci) in W\n", - "Q= 10587330.901\n", - "The exit temprature of air in °C \n", - "Tho= -923.250584257\n" - ] - } - ], - "source": [ - " \n", - " \n", - " \n", - " \n", - "import math\n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 10, Example 7\"\n", - "#Water enters a cross flow heat exchanger (both fluids unmixed) at temprature(Tci)=20°C amd flows at a mass flow rate of mdotw=7kg/s\n", - "Tci=20;\n", - "mdotw=7;\n", - "#The air flows at a mass flow rate of mdota=10kg/s from Temprature(Thi)=125°C \n", - "mdota=10;\n", - "Thi=125;\n", - "#The overall heat transfer coefficient(U)=220W/(m**2*K)and Area(A)=250m**2.\n", - "U=220;\n", - "A=250;\n", - "#The specific heat of air (cpa=1.01kJ/(kg*K)) and water is (cpw=4.18kJ/(kg*K))\n", - "cpa=1.01;\n", - "cpw=4.18;\n", - "#Cair and Cwater are heat capacities of air and water respectively\n", - "Cair=mdota*cpa;\n", - "Cwater=mdotw*cpw;\n", - "#C=Cmin/Cmax\n", - "Cmin=min(Cwater,Cair);\n", - "Cmax=max(Cwater,Cair);\n", - "C=Cmin/Cmax;\n", - "#NTU is number of transfer units\n", - "#NTU=(U*A)/Cmin\n", - "print\"NTU is defined as (U*A)/Cmin \"\n", - "NTU=(U*A)/(Cmin*1000)\n", - "print\"NTU=\",NTU\n", - "#To determine the effectiveness of heat exchanger we have to find out the suitable expression \n", - "#For this type of heat exchanger The effectiveness(eff)is determined by (1-e**((NTU**.22*(e**-(C*NTU**0.78)-1)/C)\n", - "print\"The effectiveness of heat exchanger is\"\n", - "eff=(1-math.e**((NTU**0.22))*(math.e**(-C*NTU**0.78)-1)/C)\n", - "print\"eff=\",eff\n", - "#Hence The total heat transfer rate(Q)=eff*Cmin*(Thi-Tci)in W.\n", - "print\"The total heat transfer rate(Q)=eff*Cmin*(Thi-Tci) in W\"\n", - "Q=eff*Cmin*1000*(Thi-Tci)\n", - "print\"Q=\",Q\n", - "#The exit temprature(Tho) of air is given by Thi-(Q/(mdota*cpa))\n", - "print\"The exit temprature of air in °C \"\n", - "Tho=Thi-(Q/(mdota*1000*cpa))#NOTE:-The answer slightly varies from the answer in book(i.e Tho=26°C) because the value of Q taken in book is approximated to 1*10**6W.\n", - "print\"Tho=\",Tho\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex10.8:pg-437" - ] - }, - { - "cell_type": "code", - "execution_count": 10, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 10, Example 8\n", - "(a)Considering a parallel flow arrangement \n", - "Tho= 50\n", - "The minimum flow rate required for the oil in kg/s\n", - "mdoth= 2.22340425532\n", - "(b)Theoretical question\n", - "If LMTD--->0,Then for a finite value of heat transfer rate U*A--->infinity.For a given finite length this implies value of U which is not possible.\n", - "(c)Let us consider a counter flow arrangement\n", - "The minimum flow rate required for the oil in kg/s\n", - "Ch= 2.78666666667\n", - "Cc= 8.36\n", - "Effectiveness of heat exchanger is \n", - "eff= 1.0\n" - ] - } - ], - "source": [ - " \n", - " \n", - " \n", - " \n", - "import math\n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 10, Example 8\"\n", - "#A double pipe heat exchanger of length(L)=0.30m is to be used to heat water(specific heat,cc=4.18kJ/(kg*K)) and mass flow rate(mdotw=2kg/s)\n", - "L=0.30;\n", - "cc=4.18;\n", - "mdotw=2;\n", - "#The water enters at temprature(Tci)=25°C and leaves at temprature(Tco)=50°C\n", - "#The flow rate of oil is mdoth\n", - "Tci=25;\n", - "Tco=50; \n", - "#The oil used as hot fluid has(specific heat,ch=1.88kJ/(kg*K)) and has inlet temprature(Thi)=100°C \n", - "ch=1.88;\n", - "Thi=100;\n", - "print\"(a)Considering a parallel flow arrangement \"\n", - "#For minimum value of mdoth\n", - "#The theoretical minimum value of outlet temprature of hot fluid(Tho) under this situation is equal to Tco\n", - "Tho=Tco;\n", - "print\"Tho=\",Tho\n", - "#The mass flow rate of oil is given by energy balance as mdoth=(mdotw*cpw*(Tco-Tci))/(cph*(Thi-Tho))\n", - "print\"The minimum flow rate required for the oil in kg/s\"\n", - "mdoth=(mdotw*cc*(Tco-Tci))/(ch*(Thi-Tho))\n", - "print\"mdoth=\",mdoth\n", - "print\"(b)Theoretical question\"\n", - "print\"If LMTD--->0,Then for a finite value of heat transfer rate U*A--->infinity.For a given finite length this implies value of U which is not possible.\"\n", - "print\"(c)Let us consider a counter flow arrangement\"\n", - "#In this case value of Tho=Tci.\n", - "Tho=Tci;\n", - "#The mass flow rate of oil is given by energy balance as mdoth=(mdotw*cpw*(Tco-Tci))/(cph*(Thi-Tho))\n", - "print\"The minimum flow rate required for the oil in kg/s\"\n", - "mdoth=(mdotw*cc*(Tco-Tci))/(ch*(Thi-Tci))\n", - "#Now Heat capacities are Ch=mdoth*ch and Cc=mdotw*cc\n", - "Ch=mdoth*ch; \n", - "Cc=mdotw*cc;\n", - "print\"Ch=\",Ch\n", - "print\"Cc=\",Cc\n", - "Cmin=min(Ch,Cc);#minimum heat capacity in Ch and Cc \n", - "#Effectiveness of heat exchanger is eff.\n", - "#Tho=Tci for this kind of arrangement\n", - "Tho=Tci;\n", - "print\"Effectiveness of heat exchanger is \"\n", - "eff=(mdoth*ch*(Thi-Tho))/(mdoth*ch*(Thi-Tci))\n", - "print\"eff=\",eff\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n" - ] - } - ], - "metadata": { - "kernelspec": { - "display_name": "Python 2", - "language": "python", - "name": "python2" - }, - "language_info": { - "codemirror_mode": { - "name": "ipython", - "version": 2 - }, - "file_extension": ".py", - "mimetype": "text/x-python", - "name": "python", - "nbconvert_exporter": "python", - "pygments_lexer": "ipython2", - "version": "2.7.11" - } - }, - "nbformat": 4, - "nbformat_minor": 0 -} diff --git a/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter11.ipynb b/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter11.ipynb index c44923f7..a46cced0 100644 --- a/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter11.ipynb +++ b/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter11.ipynb @@ -35,6 +35,10 @@ } ], "source": [ + " \n", + " \n", + " \n", + " \n", "import math\n", " \n", "print\"Introduction to heat transfer by S.K.Som, Chapter 11, Example 3\"\n", @@ -53,7 +57,7 @@ "A1=2;\n", "A3=2.5;\n", "F31=(A1/A3)*F13\n", - "print\"F31=\",F31" + "print\"F31=\",F31\n" ] }, { @@ -83,6 +87,10 @@ } ], "source": [ + " \n", + " \n", + " \n", + " \n", "import math\n", " \n", "print\"Introduction to heat transfer by S.K.Som, Chapter 11, Example 4\"\n", @@ -108,7 +116,11 @@ "#This implies F14=((F1,2-4*(A1+A2)))-A2*F24)/A2\n", "print\"The view factor F14=((F1,2-4*(A1+A2)))-A2*F24)/A2\"\n", "F14=((F124*(A1+A2))-(A2*F24))/A2\n", - "print\"F14=\",F14" + "print\"F14=\",F14\n", + "\n", + "\n", + "\n", + " \n" ] }, { @@ -137,6 +149,10 @@ } ], "source": [ + " \n", + " \n", + " \n", + " \n", "import math\n", " \n", "print\"Introduction to heat transfer by S.K.Som, Chapter 11, Example 5\"\n", @@ -155,7 +171,7 @@ "#Let A1/A2=A\n", "A=1/4;\n", "F31=(A)*F13\n", - "print\"F31=\",F31" + "print\"F31=\",F31\n" ] }, { @@ -190,6 +206,10 @@ } ], "source": [ + " \n", + " \n", + " \n", + " \n", "import math\n", " \n", "print\"Introduction to heat transfer by S.K.Som, Chapter 11, Example 6\"\n", @@ -232,7 +252,27 @@ "#Therefore we can write Q1=A1*sigma*(T1**4-F12*T2**4-F1s*Ts**4)\n", "print\"The net rate of energy loss from the surface at 127°C if the surrounding other than the two surfaces act as black body at 300K in W \"\n", "Q1=A1*sigma*(T1**4-F12*T2**4-F1s*Ts**4)\n", - "print\"Q1=\",Q1" + "print\"Q1=\",Q1\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n" ] }, { @@ -262,6 +302,10 @@ } ], "source": [ + " \n", + " \n", + " \n", + " \n", "import math\n", " \n", "print\"Introduction to heat transfer by S.K.Som, Chapter 11, Example 7\"\n", @@ -283,7 +327,17 @@ "#So,The net rate of heat transfer when the two surfaces are black is Q/A=sigma*(T1**4-T2**4)\n", "print\"The net rate of heat transfer when the two surfaces are black is Q/A=sigma*(T1**4-T2**4) in W\"\n", "H=sigma*(T1**4-T2**4)\n", - "print\"H=\",H" + "print\"H=\",H\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n" ] }, { @@ -317,6 +371,10 @@ } ], "source": [ + " \n", + " \n", + " \n", + " \n", "import math\n", " \n", "print\"Introduction to heat transfer by S.K.Som, Chapter 11, Example 8\"\n", @@ -353,7 +411,20 @@ "print\"Q2=\",Q2\n", "print\"Error(E) is given By ((Q2-Q1)/Q1)*100 in percentage\"\n", "E=((Q2-Q1)/Q1)*100\n", - "print\"E=\",E" + "print\"E=\",E\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n" ] }, { @@ -384,6 +455,10 @@ } ], "source": [ + " \n", + " \n", + " \n", + " \n", "import math\n", " \n", "print\"Introduction to heat transfer by S.K.Som, Chapter 11, Example 10\"\n", @@ -428,7 +503,19 @@ "#So Q/A=(sigma*(T1**4-T2**4))/(R)\n", "#Let Q/A=H\n", "H=(sigma*(T1**4-T2**4))/(R)\n", - "print\"H=\",H" + "print\"H=\",H\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n" ] } ], diff --git a/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter11_5r7Matr.ipynb b/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter11_5r7Matr.ipynb deleted file mode 100644 index a46cced0..00000000 --- a/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter11_5r7Matr.ipynb +++ /dev/null @@ -1,543 +0,0 @@ -{ - "cells": [ - { - "cell_type": "markdown", - "metadata": { - "collapsed": true - }, - "source": [ - "# Chapter 11:Radiation heat transfer" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex11.3:pg-445" - ] - }, - { - "cell_type": "code", - "execution_count": 1, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 11, Example 3\n", - "The view factors F13 and F31 between the surfaces 1 and 3 are \n", - "F13= 0.04\n", - "F31= 0.032\n" - ] - } - ], - "source": [ - " \n", - " \n", - " \n", - " \n", - "import math\n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 11, Example 3\"\n", - "print\"The view factors F13 and F31 between the surfaces 1 and 3 are \"\n", - "#Determine the view factors F13 and F31 between the surfaces 1 and 3.\n", - "#F1-2,3=F12+F13\n", - "#So F13=F1-2,3-F12\n", - "#Let F1-2,3=F123\n", - "#From Radiation Shape factor b/w two perpendicular rectangles with a commom edge table we get F12=.027,F1-2,3=0.31\n", - "F123=0.31;#View factor\n", - "F12=.27;#View factor\n", - "F13=F123-F12#View factor\n", - "print\"F13=\",F13\n", - "#A1,A2 and A3 are the emitting surface areas\n", - "#From reciprocity relation F31=(A1/A3)/F13\n", - "A1=2;\n", - "A3=2.5;\n", - "F31=(A1/A3)*F13\n", - "print\"F31=\",F31\n" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex11.4:pg-447" - ] - }, - { - "cell_type": "code", - "execution_count": 3, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 11, Example 4\n", - "F124= 0.04\n", - "F24= 0.06\n", - "The view factor F14=((F1,2-4*(A1+A2)))-A2*F24)/A2\n", - "F14= 0.02\n" - ] - } - ], - "source": [ - " \n", - " \n", - " \n", - " \n", - "import math\n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 11, Example 4\"\n", - "#Determine the view factors F14 for the composite surface .\n", - "#From the table of radiation shape factor b/w two perpendicular surfaces F1,2-3,4=0.14 and F1,2-3=0.1\n", - "#By subdivision of the recieving surfaces we get F1,2-4=F1,2-3,4-F1,2-3\n", - "#Let F1,2-4=F124 , F1,2-3,4=F1234 , F1,2-3=F123\n", - "F1234=0.14;#View factor\n", - "F123=0.1;#View factor\n", - "F124=F1234-F123;#View factor\n", - "print\"F124=\",F124\n", - "#Again from the table of radiation shape factor b/w two perpendicular surfaces F2-3,4=0.24 , F23=0.18\n", - "#Let F2-3,4=F234\n", - "F234=0.24;#View factor\n", - "F23=0.18;#View factor\n", - "#By subdivision of the recieving surfaces we get F24=F2-3,4-F23\n", - "F24=F234-F23;#view factor\n", - "print\"F24=\",F24\n", - "#A1 and A2 are the emitting surface areas.\n", - "A1=12;\n", - "A2=12;\n", - "#Now by subdivision of emitting surfaces F1,2-4=(1/(A1+A2))*(A1*F14+A2*F24)\n", - "#This implies F14=((F1,2-4*(A1+A2)))-A2*F24)/A2\n", - "print\"The view factor F14=((F1,2-4*(A1+A2)))-A2*F24)/A2\"\n", - "F14=((F124*(A1+A2))-(A2*F24))/A2\n", - "print\"F14=\",F14\n", - "\n", - "\n", - "\n", - " \n" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex11.5:pg-453" - ] - }, - { - "cell_type": "code", - "execution_count": 4, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 11, Example 5\n", - "The view factors of cylindrical surface with respect to the base are\n", - "F13= 0.84\n", - "F31= 0.0\n" - ] - } - ], - "source": [ - " \n", - " \n", - " \n", - " \n", - "import math\n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 11, Example 5\"\n", - "#Consider a cylinder having length,L=2r determine the view factor of cylindrical surface with respect to the base.\n", - "#From the graph of radiation shape factor b/w parallel coaxial disks of equal diameter F12=0.16\n", - "F12=0.16;#View factor\n", - "#By the summation rule of an enclosure F11+F12+F13=1\n", - "#But F11=0(since the base surface is flat)\n", - "F11=0;#View factor\n", - "print\"The view factors of cylindrical surface with respect to the base are\"\n", - "F13=1-F12-F11#view factor\n", - "print\"F13=\",F13\n", - "#By making use of reciprocity theorem we have F31=(A1/A2)*F13\n", - "#A1 and A2 are emitting surface areas\n", - "#A1/A2=(pi*r**2)/(2*pi*r*2*r)=1/4\n", - "#Let A1/A2=A\n", - "A=1/4;\n", - "F31=(A)*F13\n", - "print\"F31=\",F31\n" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex11.6:pg-456" - ] - }, - { - "cell_type": "code", - "execution_count": 5, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 11, Example 6\n", - "The rate of heat transfer is given by Q=A1*F12*sigma*(T1**4-T2**4) in W\n", - "Q= -2918.916\n", - "Here minus sign indicates that the net heat transfer is from surface2 to surface1\n", - "The net rate of energy loss from the surface at 127°C if the surrounding other than the two surfaces act as black body at 0K in W\n", - "Q1= 2894.4216\n", - "The view factor of surface 1 with respect to surrounding is\n", - "F1s= 0.89\n", - "The net rate of energy loss from the surface at 127°C if the surrounding other than the two surfaces act as black body at 300K in W \n", - "Q1= 1055.04525\n" - ] - } - ], - "source": [ - " \n", - " \n", - " \n", - " \n", - "import math\n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 11, Example 6\"\n", - "#Two rectangles length,L=1.5m by breadth,B=3.0m are parallel and directly opposed.\n", - "L=1.5;\n", - "B=3;\n", - "#They are 3m apart\n", - "#Temprature(T1) of surface 1 is 127°C or 400K and temprature(T2) of surface 2 is 327°C or 600K \n", - "T1=400;\n", - "T2=600;\n", - "#Area (A) is the product of L and B\n", - "A1=L*B;\n", - "#Stefan -Boltzman constant(sigma)=5.67*10**-8 W/(m**2*K**4)\n", - "sigma=5.67*10**-8;\n", - "#From the graph of radiation shape factor b/w parallel rectangles F12=0.11\n", - "F12=0.11;#View factor\n", - "#The rate of heat transfer is given by Q=A1*F12*sigma*(T1**4-T2**4)\n", - "print\"The rate of heat transfer is given by Q=A1*F12*sigma*(T1**4-T2**4) in W\"\n", - "Q=A1*F12*sigma*(T1**4-T2**4)\n", - "print\"Q=\",Q\n", - "print\"Here minus sign indicates that the net heat transfer is from surface2 to surface1\"\n", - "#Surface1 recieves energy only from surface 2,since the surrounding is at 0K.\n", - "#Therefore Q1=A1*Eb1-A2*F21*Eb2\n", - "#This implies Q1 can also be written as A1*sigma*(T1**4-F12*T2**4)\n", - "#From reciprocity theorem F21=F12 (since A1=A2)\n", - "F21=F12;#view factor\n", - "print\"The net rate of energy loss from the surface at 127°C if the surrounding other than the two surfaces act as black body at 0K in W\" \n", - "Q1=A1*sigma*(T1**4-F12*T2**4)\n", - "print\"Q1=\",Q1\n", - "#In the case when surrounding is at temprature, Ts=300K ,the energy recieved from the surrounding by the surface 1 has to be considered.\n", - "Ts=300;\n", - "#Applying summation rule of view factors F11+F12+F1s=1\n", - "F11=0;#view factor\n", - "print\"The view factor of surface 1 with respect to surrounding is\"\n", - "F1s=1-F11-F12\n", - "print\"F1s=\",F1s\n", - "#subscript s denotes the surroundings\n", - "#Q1=A1*Eb1-A2*F21*Eb2-As*Fs1*Ebs\n", - "#With the help of reciprocity theorem A2*F21=A1*F12 , As*Fs1=A1*F1s\n", - "#Therefore we can write Q1=A1*sigma*(T1**4-F12*T2**4-F1s*Ts**4)\n", - "print\"The net rate of energy loss from the surface at 127°C if the surrounding other than the two surfaces act as black body at 300K in W \"\n", - "Q1=A1*sigma*(T1**4-F12*T2**4-F1s*Ts**4)\n", - "print\"Q1=\",Q1\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex11.7:pg-470" - ] - }, - { - "cell_type": "code", - "execution_count": 10, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 11, Example 7\n", - "The net rate of heat transfer per unit area is given Q/A=(sigma*(T1**4-T2**4))/((1/Æ1)+(1/Æ2)-1) in W\n", - "H= 1764.51561476\n", - "The net rate of heat transfer when the two surfaces are black is Q/A=sigma*(T1**4-T2**4) in W\n", - "H= 3276.95757027\n" - ] - } - ], - "source": [ - " \n", - " \n", - " \n", - " \n", - "import math\n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 11, Example 7\"\n", - "#Two parallel infinite surafces are maintained at tempratures T2=200°C or 473.15K and T1=300°C or 573.15K\n", - "T1=573.15;\n", - "T2=473.15;\n", - "#The emissivity(emi) is 0.7 for both the surfaces which are gray.\n", - "emi1=0.7;\n", - "emi2=0.7;\n", - "#stefan=boltzman constant(sigma)=5.67*10**-8W/(m**2*K**4)\n", - "sigma=5.67*10**-8;\n", - "#The net rate of heat transfer per unit area is given Q/A=(sigma*(T1**4-T2**4))/((1/Æ1)+(1/Æ2)-1)\n", - "#Let Q/A=H\n", - "print\"The net rate of heat transfer per unit area is given Q/A=(sigma*(T1**4-T2**4))/((1/Æ1)+(1/Æ2)-1) in W\"\n", - "H=(sigma*(T1**4-T2**4))/((1/emi1)+(1/emi2)-1)\n", - "print\"H=\",H\n", - "#When the two surfaces are black\n", - "#This implies emiisivity(emi)=1 for both surfaces\n", - "#So,The net rate of heat transfer when the two surfaces are black is Q/A=sigma*(T1**4-T2**4)\n", - "print\"The net rate of heat transfer when the two surfaces are black is Q/A=sigma*(T1**4-T2**4) in W\"\n", - "H=sigma*(T1**4-T2**4)\n", - "print\"H=\",H\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex11.8:pg-482" - ] - }, - { - "cell_type": "code", - "execution_count": 8, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 11, Example 8\n", - "The net rate of heat exchange between the spheres when the surfaces are black is Q=A1*sigma*(T1**4-T2**4) in W \n", - "Q= 779.311327631\n", - "The net rate of radiation exchange when one surface is gray and other is diffuse is given by Q1=(A1*sigma*(T1**4-T2**4))/((1/emi1)+(A1/A2)*(1/emi2-1)) in W\n", - "Q1= 346.360590058\n", - "The net rate of radiation exchange when outer surface is assumed to be black body i;e(emi2=1) in W\n", - "Q2= 389.655663816\n", - "Error(E) is given By ((Q2-Q1)/Q1)*100 in percentage\n", - "E= 12.5\n" - ] - } - ], - "source": [ - " \n", - " \n", - " \n", - " \n", - "import math\n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 11, Example 8\"\n", - "#Two concentric spheres of diameters D1=0.5m and D2=1m are separated by an air space.\n", - "#The surface tempratures are T1=400K and T2=300K\n", - "T1=400;\n", - "T2=300;\n", - "D1=0.5;\n", - "D2=1;\n", - "#A1 and A2 are the areas in m**2 of surface 1 and surface 2 respectively\n", - "A1=(math.pi*D1**2);\n", - "A2=(math.pi*D2**2);\n", - "#Stefan-Boltzman constant(sigma)=5.67*10**-8 W/(m**2*K**4)\n", - "sigma=5.67*10**-8;\n", - "#The emissivity is represented by emi \n", - "#The radiation heat exchange in case of two concentric sphere is given by Q=(A1*sigma*(T1**4-T2**4))/((1/emi1)+(A1/A2)*(1/emi2-1)) \n", - "#When the spheres are black emi1=emi2=1\n", - "emi1=1;\n", - "emi2=1;\n", - "#Hence Q=A1*sigma*(T1**4-T2**4)\n", - "print\"The net rate of heat exchange between the spheres when the surfaces are black is Q=A1*sigma*(T1**4-T2**4) in W \"\n", - "Q=A1*sigma*(T1**4-T2**4)\n", - "print\"Q=\",Q\n", - "#The net rate of radiation exchange when one surface is gray and other is diffuse having emi1=0.5 and emi2=0.5 \n", - "emi1=0.5;\n", - "emi2=0.5;\n", - "print\"The net rate of radiation exchange when one surface is gray and other is diffuse is given by Q1=(A1*sigma*(T1**4-T2**4))/((1/emi1)+(A1/A2)*(1/emi2-1)) in W\" \n", - "Q1=(A1*sigma*(T1**4-T2**4))/((1/emi1)+(A1/A2)*(1/emi2-1))\n", - "print\"Q1=\",Q1\n", - "#The net rate of radiation exchange when outer surface is assumed to be black body i;e(emi2=1)\n", - "emi2=1;#emissivity of outer surface\n", - "print\"The net rate of radiation exchange when outer surface is assumed to be black body i;e(emi2=1) in W\"\n", - "Q2=(A1*sigma*(T1**4-T2**4))/((1/emi1)+(A1/A2)*(1/emi2-1))\n", - "print\"Q2=\",Q2\n", - "print\"Error(E) is given By ((Q2-Q1)/Q1)*100 in percentage\"\n", - "E=((Q2-Q1)/Q1)*100\n", - "print\"E=\",E\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex11.10:pg-484" - ] - }, - { - "cell_type": "code", - "execution_count": 6, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 11, Example 10\n", - "F12= 0.5\n", - "Equivalent resistance of thermal network (R) is given by R1+((1/R12)+(1/(R13+R23)))**-1+R2\n", - "R= 2.09523809524\n", - "The radiation flux leaving the hot wall is Q/A=[sigma*(T1**4-T2**4)]/(A*R) in W/m**2\n", - "H= 26655.2740483\n" - ] - } - ], - "source": [ - " \n", - " \n", - " \n", - " \n", - "import math\n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 11, Example 10\"\n", - "#Given a furnace which can be approximated as an equuilateral triangle duct\n", - "#The hot wall is maintained at temprature (T1)=1000K and has emmisivity(emi1)=0.75\n", - "#The cold wall is at temprature(T2)=350K and has emmisivity(emi2)=0.7\n", - "T1=1000;\n", - "T2=350;\n", - "emi1=0.75;\n", - "emi2=0.7;\n", - "#Stefan-Boltzman constant(sigma)=5.67*10**-8 W/(m**2*K**4)\n", - "sigma=5.67*10**-8;\n", - "#The third wall is reradiating zone having Q3=0\n", - "#The radiation flux leaving the hot wall is Q/A=(sigma*(T1**4-T2**4))/(A*R)\n", - "#By summation rule F33+F31+F32=1\n", - "#F33=0(in consideration of surface to be plane)\n", - "#From symmetry F31=F32\n", - "F31=0.5;#View factors\n", - "F32=F31;#View factors\n", - "F33=0;#View factors\n", - "#From reciprocity theorem F13=F31 and F23=F32=0.5 (since A1=A2=A3=A)\n", - "F13=F31;#View factors\n", - "F23=F32;#View factors\n", - "#Again F11+F12+F13=1 from summation rule\n", - "F11=0;#View factors\n", - "F12=1-F13-F11;#View factors\n", - "print\"F12=\",F12\n", - "#R1,R2,R12,R13,R23 are the resistances\n", - "#R is equivalent resistance of thermal network is given by R1+((1/R12)+(1/(R13+R23)))**-1+R2\n", - "R1=(1-emi1)/(emi1);\n", - "R2=(1-emi2)/(emi2);\n", - "R12=1/(F12);\n", - "R13=1/(F13);\n", - "R23=1/(F23);\n", - "#R is equivalent resistance of thermal network \n", - "print\"Equivalent resistance of thermal network (R) is given by R1+((1/R12)+(1/(R13+R23)))**-1+R2\"\n", - "R=R1+((1/R12)+(1/(R13+R23)))**-1+R2\n", - "print\"R=\",R\n", - "#The radiation flux leaving the hot wall is Q/A.\n", - "print\"The radiation flux leaving the hot wall is Q/A=[sigma*(T1**4-T2**4)]/(A*R) in W/m**2\"\n", - "#Since A gets cancelled in the factor (A*R)\n", - "#So Q/A=(sigma*(T1**4-T2**4))/(R)\n", - "#Let Q/A=H\n", - "H=(sigma*(T1**4-T2**4))/(R)\n", - "print\"H=\",H\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n" - ] - } - ], - "metadata": { - "kernelspec": { - "display_name": "Python 2", - "language": "python", - "name": "python2" - }, - "language_info": { - "codemirror_mode": { - "name": "ipython", - "version": 2 - }, - "file_extension": ".py", - "mimetype": "text/x-python", - "name": "python", - "nbconvert_exporter": "python", - "pygments_lexer": "ipython2", - "version": "2.7.11" - } - }, - "nbformat": 4, - "nbformat_minor": 0 -} diff --git a/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter1_QhYeq33.ipynb b/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter1_QhYeq33.ipynb deleted file mode 100644 index d9d7f745..00000000 --- a/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter1_QhYeq33.ipynb +++ /dev/null @@ -1,529 +0,0 @@ -{ - "cells": [ - { - "cell_type": "markdown", - "metadata": { - "collapsed": true - }, - "source": [ - "# Chapter 01:Fundamental concepts" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex1.1:pg- 4" - ] - }, - { - "cell_type": "code", - "execution_count": 4, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 1, Example 1\n", - "The steady state heat transfer rate per unit area through the thick slab is given by q=k(T1-T2)/L in W/m**2 \n", - "q= 50.0\n" - ] - } - ], - "source": [ - "import math\n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 1, Example 1\"\n", - "#The temprature of two faces of the slabs are T1=40°C & T2=20°C \n", - "#The thickness of the slab(L) is 80mm or .08m\n", - "#The thermal conductivity(k)of the material is .20 W/(m*K)\n", - "T1=40;\n", - "T2=20;\n", - "L=.08;\n", - "k=.20;\n", - "#The steady state heat transfer rate per unit area through the thick slab is given by q=k(T1-T2)/L\n", - "print\"The steady state heat transfer rate per unit area through the thick slab is given by q=k(T1-T2)/L in W/m**2 \"\n", - "q=k*(T1-T2)/L\n", - "print\"q=\",q" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex1.2:pg- 4" - ] - }, - { - "cell_type": "code", - "execution_count": 5, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 1, Example 2\n", - "The thickness of masonry wall is Lm in m\n", - "Lm= 0.5\n" - ] - } - ], - "source": [ - "import math\n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 1, Example 2\"\n", - "#The thermal conductivity(km)of masonry wall is .8 W/(mK)\n", - "#The thermal conductivity(kc)of composite wall is .2 W/(mK)\n", - "#The thickness of composite wall(Lc) is 100 mm or .1 m\n", - "km=.8;\n", - "kc=.2;\n", - "Lc=.1;\n", - "#The thickness of masonry wall(Lm) is to be found. \n", - "#The steady state heat flow(qm)through masonry wall is km(T1-T2)/L\n", - "# The steady state heat flow(qc)through composite wall is kc(T1-T2)/L\n", - "#As the steady rate of heat flow through masonry wall is 80% that through composite wall and both the wall have same surface area and same temp. difference so qm/qc=0.8=(km/kc)*(Lc/Lm)\n", - "#The thickness of masonry wall is Lm.\n", - "print\"The thickness of masonry wall is Lm in m\"\n", - "Lm=(km/kc)*(Lc/(0.8))\n", - "print\"Lm=\",Lm\n" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex1.4:pg-8" - ] - }, - { - "cell_type": "code", - "execution_count": 6, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 1, Example 4\n", - "The rate of heat transfer per unit area q=hbr*(Tinf-Ts) in W/m**2\n", - "q= 16000\n" - ] - } - ], - "source": [ - "import math\n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 1, Example 4\"\n", - "#The average forced convective heat transfer coefficient(hbr) is 200 W/( m**2 °C)\n", - "#The fluid temprature(Tinf) upstream of the cold surface is 100°C\n", - "#The surface temprature(Ts) is 20°C\n", - "hbr=200;\n", - "Tinf=100;\n", - "Ts=20;\n", - "#The rate of heat transfer per unit area is q\n", - "print\"The rate of heat transfer per unit area q=hbr*(Tinf-Ts) in W/m**2\"\n", - "q=hbr*(Tinf-Ts)\n", - "print\"q=\",q" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex1.5:pg-9" - ] - }, - { - "cell_type": "code", - "execution_count": 7, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 1, Example 5\n", - "The heat exchanger surface area(A)in m**2 required for 20 MJ/h of heating is \n", - "A= 0\n" - ] - } - ], - "source": [ - "import math\n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 1, Example 5\"\n", - "#The average heat transfer coefficient(hbr) is 800 W/(m**2°C)\n", - "#The surface temprature of heat exchanger is 75°C and air temprature is 25°C so deltaT=(75-25)\n", - "#The amount of heat exchanged(Q) is 20 MJ/h\n", - "#The heat exchanger surface area(A) is given by A=Q/(hbr*∆T)\n", - "hbr=800;\n", - "deltaT=(75-25);\n", - "Q=20;\n", - "print\"The heat exchanger surface area(A)in m**2 required for 20 MJ/h of heating is \"\n", - "A = (Q*10**6)/(3600*hbr*deltaT)\n", - "print\"A=\",A" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex1.6:pg-9" - ] - }, - { - "cell_type": "code", - "execution_count": 3, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 1, Example 6\n", - "The rate of heat transfer from the plate is given by Q=hbr*A*(Ts-Tinf)\n", - "Equating the above two equations we get hbr=(m*cp*|dT/dt|)/(A*(Ts-Tinf)) in W/(m**2°C)\n", - "hbr= 11.2\n", - "The rate of heat transfer can also be written in the form of Q=m*cp*|dT/dt| from an energy balance.\n", - "Q= 224.0\n", - "Equating the above two equations we get hbr=(m*cp*|dT/dt|)/(A*(Ts-Tinf)) in W/(m**2°C)\n" - ] - } - ], - "source": [ - "import math\n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 1, Example 6\"\n", - "#The temprature of the plate(Ts) is 225°C\n", - "#The ambient temprature (Tinf) is 25°C\n", - "#The change in plate temprature with time is dT/dt=-.02K/s\n", - "#The plate area (A)=.1m**2 , mass(m)= 4Kg and specific heat(cp)=2.8KJ/(Kg*K)\n", - "#The average free convective heat coefficient(hbr) is to be found\n", - "Ts=225;\n", - "Tinf=25;\n", - "#|dT/dt|=0.2,because it is modulus function and it converts negative values to positive value.\n", - "#Let |dT/dt|=X\n", - "X=0.02;\n", - "A=.1;\n", - "m=4;\n", - "cp=2.8;\n", - "print\"The rate of heat transfer from the plate is given by Q=hbr*A*(Ts-Tinf)\"\n", - "print\"Equating the above two equations we get hbr=(m*cp*|dT/dt|)/(A*(Ts-Tinf)) in W/(m**2°C)\"\n", - "hbr=(m*cp*10**3*X)/(A*(Ts-Tinf))\n", - "print\"hbr=\",hbr\n", - "Q=hbr*A*(Ts-Tinf)\n", - "print\"The rate of heat transfer can also be written in the form of Q=m*cp*|dT/dt| from an energy balance.\"\n", - "print\"Q=\",Q\n", - "print\"Equating the above two equations we get hbr=(m*cp*|dT/dt|)/(A*(Ts-Tinf)) in W/(m**2°C)\"\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex1.7:pg-10" - ] - }, - { - "cell_type": "code", - "execution_count": 8, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 1, Example 7\n", - "The heat flux per square meter is given by E/A=emi*sigma*T**4 in W/m**2\n", - "F= 556.4411381\n" - ] - } - ], - "source": [ - "import math\n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 1, Example 7\"\n", - "#The temprature(T) of brick wall after sunset is 50°C\n", - "#The emissity value(emi)=0.9\n", - "#The radiant heat flux per square meter =E/A Where E is radiant heat energy and A is area of brick wall.\n", - "#The stefan-Boltzman constant(sigma)=5.6697*10**-8 W/(m**2*K**4).\n", - "T=50;\n", - "emi=.9;\n", - "sigma=5.6697*10**-8;\n", - "print\"The heat flux per square meter is given by E/A=emi*sigma*T**4 in W/m**2\"\n", - "#Let E/A=F\n", - "F=emi*sigma*(T+273.15)**4\n", - "print\"F=\",F" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex1.8:pg-11" - ] - }, - { - "cell_type": "code", - "execution_count": 9, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 1, Example 8\n", - "The emitted radiant energy per unit surface area is given by Eb/A=sigma*T**4 in W/m**2\n", - "F= 618.267931222\n" - ] - } - ], - "source": [ - "import math\n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 1, Example 8\"\n", - "#The temprature(T) of asphalt pavement = 50°C\n", - "#The stefan-Boltzman constant(sigma)=5.6697*10**-8 W/(m**2*K**4).\n", - "T=50;\n", - "sigma=5.6697*10**-8;\n", - "#The emitted radiant energy per unit surface area is given by (Eb/A)=sigma*T**4\n", - "print\"The emitted radiant energy per unit surface area is given by Eb/A=sigma*T**4 in W/m**2\"\n", - "#Let Eb/A=F\n", - "F=sigma*(50+273.15)**4\n", - "print\"F=\",F\n" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex1.9:pg-12" - ] - }, - { - "cell_type": "code", - "execution_count": 10, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 1, Example 9\n", - "The rate of heat transfer per unit surface area of wall is given by Q/A=(Ta-Tb)/((1/hbr1*A)+(L/(k*A))+(1/hbr2*A))in W/m**2\n", - "F= 213.333333333\n", - "The surface tempratures of wall on 60°C side is T1 =Ta-(Q/(A*hbr1)) in °C\n", - "T1= 54.6666666667\n", - "The surface tempratures of wall on 20°C side is T2 =Tb+(Q/(A*hbr2)) in °C\n", - "T2= 41.3333333333\n" - ] - } - ], - "source": [ - "import math\n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 1, Example 9\"\n", - "#The Thickness(L) of wall= 150 mm or 0.15 m.\n", - "#The wall on one side is exposed to air at temprature(Ta)= 60°C and on the other side to air at temprature(Tb) = 20°C\n", - "#The average convective heat transfer coefficients are hbr1=40 W/(m**2°C) on the 60°C and hbr2= 10 W/(m**2°C) on 20°C side.\n", - "#The thermal conductivity(k)=.8 W/(m°C)\n", - "L=0.15;\n", - "Ta=60;\n", - "Tb=20;\n", - "hbr1=40;\n", - "hbr2=10;\n", - "k=0.8;\n", - "#Area(A=1 m**2 )since unit surface area is required.\n", - "A=1;\n", - "#The rate of heat transfer per unit surface area of wall is given by (Q/A)=(Ta-Tb)/((1/hbr1*A)+(L/(k*A))+(1/hbr2*A))\n", - "print\"The rate of heat transfer per unit surface area of wall is given by Q/A=(Ta-Tb)/((1/hbr1*A)+(L/(k*A))+(1/hbr2*A))in W/m**2\"\n", - "#Let Q/A=F\n", - "F=(Ta-Tb)/((1/hbr1*A)+(L/(k*A))+(1/hbr2*A))\n", - "print\"F=\",F\n", - "#The surface tempratures of wall on 60°C side is T1 and on 20°C side is T2\n", - "print\"The surface tempratures of wall on 60°C side is T1 =Ta-(Q/(A*hbr1)) in °C\"\n", - "T1 =Ta-(F/hbr1)\n", - "print\"T1=\",T1\n", - "print\"The surface tempratures of wall on 20°C side is T2 =Tb+(Q/(A*hbr2)) in °C\"\n", - "T2 =Tb+(F/hbr2)\n", - "print\"T2=\",T2" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex1.10:pg-13" - ] - }, - { - "cell_type": "code", - "execution_count": 11, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 1, Example 10\n", - "Heat transfer from the outer surface takes place only by radiation is given by Q/A=F1=emi*sigma*(T2**4-T0**4)in W/m**2 for different values of tempratures in K\n", - "heat transfer from the outer surface can also be written as Q/A=F2=(Ti-To)/((1/hbri)+(L/k)+(1/hr)) in W/m**2 at different tempratures in K\n", - "The values of temprature that are considered are <298 K\n", - "Satisfactory solutions for Temprature in K is\n", - "T2= 292.5\n", - "Approximate Rate of Heat Transfer in W/m**2 is\n", - "F1= 332.029390022\n", - "F2= 332.132667923\n" - ] - } - ], - "source": [ - "import math\n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 1, Example 10\"\n", - "#The spacecraft panel has thickness(L)=.01 m\n", - "#The spacecraft has inner temprature (Ti)=298 K\n", - "#The spacecraft has outer temprature(T2)\n", - "#The panel is exposed to deep space where temprature(To)= 0K\n", - "#The material has Thermal conductivity(k)= 5.0 W/(m*K)\n", - "#The emissivity(emi)=0.8\n", - "#The inner surface of the panel is exposed to airflow resulting in an average heat transfer coefficient(hbri)=70 W/(m**2*K)\n", - "L=0.01;\n", - "Ti=298.0;\n", - "To=0.0;\n", - "k=5.0;\n", - "emi=0.8;\n", - "hbri=70.0;\n", - "#The stefan Boltzman constant(sigma)= 5.67*10**-8 W/(m**2/K**4)\n", - "sigma=5.67*10**(-8);\n", - "#Heat transfer from the outer surface takes place only by radiation is given by Q/A=emi*sigma*(T2**4-T0**4)in W/m**2=F1\n", - "#heat transfer from the outer surface can also be written as Q/A=(Ti-To)/((1/hbri)+(L/k)+(1/hr))=F2\n", - "#Radiation heat transfer coefficient(hr) is defined as Q/A=hr(T2-To)\n", - "#so hr=4.536*10**-8*T2**3\n", - "print\"Heat transfer from the outer surface takes place only by radiation is given by Q/A=F1=emi*sigma*(T2**4-T0**4)in W/m**2 for different values of tempratures in K\"\n", - "print\"heat transfer from the outer surface can also be written as Q/A=F2=(Ti-To)/((1/hbri)+(L/k)+(1/hr)) in W/m**2 at different tempratures in K\"\n", - "print\"The values of temprature that are considered are <298 K\"\n", - "for i in range(285,292):\n", - " T2=i\n", - " hr=4.536*10**(-8)*i**3\n", - " F1=emi*sigma*(T2**4-To**4)\n", - " F2=(Ti-To)/((1/hbri)+(L/k)+(1/hr))\n", - "if F1==F2:\n", - " T2=i\n", - "else: \n", - " T2=292.5\n", - " hr=4.536*10**(-8)*T2**3\n", - " F1=emi*sigma*(T2**4-To**4)\n", - " F2=(Ti-To)/((1/hbri)+(L/k)+(1/hr))\n", - "print\"Satisfactory solutions for Temprature in K is\"\n", - "print\"T2=\",T2\n", - "print\"Approximate Rate of Heat Transfer in W/m**2 is\"\n", - "print\"F1=\",F1\n", - "print\"F2=\",F2" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex1.11:pg-15" - ] - }, - { - "cell_type": "code", - "execution_count": 12, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 1, Example 11\n", - "L= 1\n", - "A= 0.251327412287\n", - "The total heat loss by The pipe per unit length is given by Q/L=hbr*A*(T1-T2)+sigma*emi*A*(T1**4-T2**4) in W/m\n", - "F= 121.586773684\n" - ] - } - ], - "source": [ - "\n", - "import math \n", - "\n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 1, Example 11\"\n", - "#The horizontal steel pipe has outer diameter(D)=80 mm or.08 m\n", - "#The pipe is maintained at a temprature(T1)=60°C where the air and wall temprature(T2)=20 °C \n", - "#The average free convective heat transfer coefficient(hbr)=6.5 W/(m**2/K) b/w the outer surface of the pipe and air\n", - "D=.08;\n", - "T1=60;\n", - "T2=20;\n", - "hbr=6.5;\n", - "#Length(L=1) since per unit length is considered\n", - "L=1;\n", - "#The surface area of pipe is given by A=(math.pi*D*L)\n", - "print\"L=\",L\n", - "A=(math.pi*D*L);\n", - "#The surface emissivity(emi) of steel = 0.8\n", - "#The stefan -Boltzman constant(sigma)= 5.7*10**-8 W/(m**2*K**4)\n", - "print\"A=\",A\n", - "sigma=5.67*10**-8;\n", - "emi=.8;\n", - "#The total heat loss by The pipe per unit length is given by Q/L=hbr*A*(T1-T2)+sigma*emi*A*(T1**4-T2**4)\n", - "print\"The total heat loss by The pipe per unit length is given by Q/L=hbr*A*(T1-T2)+sigma*emi*A*(T1**4-T2**4) in W/m\"\n", - "#Let Q/L=F\n", - "F=hbr*A*((T1+273.15)-(T2+273.15))+sigma*emi*A*((T1+273.15)**4-(T2+273.15)**4)\n", - "print\"F=\",F\n", - "\n" - ] - } - ], - "metadata": { - "kernelspec": { - "display_name": "Python 2", - "language": "python", - "name": "python2" - }, - "language_info": { - "codemirror_mode": { - "name": "ipython", - "version": 2 - }, - "file_extension": ".py", - "mimetype": "text/x-python", - "name": "python", - "nbconvert_exporter": "python", - "pygments_lexer": "ipython2", - "version": "2.7.11" - } - }, - "nbformat": 4, - "nbformat_minor": 0 -} diff --git a/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter2.ipynb b/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter2.ipynb index cda3a92c..ba64d857 100644 --- a/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter2.ipynb +++ b/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter2.ipynb @@ -18,7 +18,7 @@ }, { "cell_type": "code", - "execution_count": 1, + "execution_count": 2, "metadata": { "collapsed": false }, @@ -119,7 +119,31 @@ "print\"Check for Ti(in °C)\"\n", "Ti=T4-(Q*Ri)\n", "print\"The value is same as given in the problem\"\n", - "print\"Ti=\",Ti" + "print\"Ti=\",Ti\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + " \n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n" ] }, { @@ -147,6 +171,10 @@ } ], "source": [ + " \n", + "\n", + " \n", + " \n", "import math\n", " \n", "print\"Introduction to heat transfer by S.K.Som, Chapter 2, Example 2\"\n", @@ -166,7 +194,7 @@ "#Q=(Ti-To)/((Lb/kb)+(L/ki)) so L=ki*(((Ti-To)/Q)-(Lb/kb))\n", "print\"The thickness of insulating material L=ki*(((Ti-To)/Q)-(Lb/kb)) in m\"\n", "L=ki*(((Ti-To)/Q)-(Lb/kb))\n", - "print\"L=\",L" + "print\"L=\",L\n" ] }, { @@ -178,7 +206,7 @@ }, { "cell_type": "code", - "execution_count": 3, + "execution_count": 1, "metadata": { "collapsed": false }, @@ -207,6 +235,7 @@ } ], "source": [ + " \n", "import math\n", " \n", "print\"Introduction to heat transfer by S.K.Som, Chapter 2, Example 4\"\n", @@ -252,7 +281,17 @@ "print\"q2=\",q2\n", "print\"Heat flux qo=q1+q2 in W/m**2 \"\n", "qo=q1+q2\n", - "print\"qo=\",qo" + "print\"qo=\",qo\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n" ] }, { @@ -290,6 +329,7 @@ } ], "source": [ + " \n", "import math\n", " \n", "print\"Introduction to heat transfer by S.K.Som, Chapter 2, Example 6\"\n", @@ -332,7 +372,9 @@ "X=(2*10**3)-(4*10**5*x);\n", "Q=-k*X/10**6\n", "#A check for the above results can be made from an energy balance of the plate as |(q/A)|@x=0+|(q/A)|@x=0.02=qG*0.02\n", - "print\"Q=\",Q" + "print\"Q=\",Q\n", + "\n", + "\n" ] }, { @@ -344,7 +386,7 @@ }, { "cell_type": "code", - "execution_count": 16, + "execution_count": 2, "metadata": { "collapsed": false }, @@ -368,6 +410,7 @@ } ], "source": [ + " \n", "import math\n", " \n", "print\"Introduction to heat transfer by S.K.Som, Chapter 2, Example 9\"\n", @@ -415,7 +458,16 @@ "Q=(T1-Tinf)/(((X)/(2*math.pi*L*k))+(1/(h*2*math.pi*r2*L)))\n", "#It is important to note that Q increases by 5.2% when the insulation thickness increases from 0.002m to critical thickness. \n", "#Addition of insulation beyond the critical thickness decreases the value of Q (The heat loss).\n", - "print\"Q=\",Q" + "print\"Q=\",Q\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n" ] }, { @@ -427,7 +479,7 @@ }, { "cell_type": "code", - "execution_count": 8, + "execution_count": 3, "metadata": { "collapsed": false }, @@ -443,6 +495,7 @@ } ], "source": [ + " \n", "import math\n", " \n", "print\"Introduction to heat transfer by S.K.Som, Chapter 2, Example 10\"\n", @@ -472,7 +525,22 @@ "#Therefore the thickness of insulation is given by t=r3-Do\n", "print\"the thickness of insulation in metre is\"\n", "t=r3-Do\n", - "print\"t=\",t" + "print\"t=\",t\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n" ] }, { @@ -484,7 +552,7 @@ }, { "cell_type": "code", - "execution_count": 9, + "execution_count": 4, "metadata": { "collapsed": false }, @@ -502,6 +570,7 @@ } ], "source": [ + " \n", "import math\n", " \n", "print\"Introduction to heat transfer by S.K.Som, Chapter 2, Example 11\"\n", @@ -522,7 +591,21 @@ "print\"The temprature of wire at the centre in K is \"\n", "To=Tw+((qG*ro**2)/(4*k))\n", "#Note:The answer in the book is incorrect(value of D has been put instead of ro)\n", - "print\"To=\",To" + "print\"To=\",To\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n" ] }, { @@ -572,6 +655,10 @@ } ], "source": [ + "\n", + " \n", + " \n", + " \n", "import math\n", " \n", "print\"Introduction to heat transfer by S.K.Som, Chapter 2, Example 12\"\n", @@ -643,7 +730,12 @@ "#the amount of ice in kG which melts during a 24 hour period is (mice)\n", "print\"Therefore,the amount of ice(mice)in kG which melts during a 24 hour period is\"\n", "mice=Qt/deltahf\n", - "print\"mice=\",mice" + "print\"mice=\",mice\n", + "\n", + "\n", + "\n", + "\n", + "\n" ] }, { @@ -655,7 +747,7 @@ }, { "cell_type": "code", - "execution_count": 13, + "execution_count": 5, "metadata": { "collapsed": false }, @@ -690,6 +782,7 @@ } ], "source": [ + " \n", "import math\n", " \n", "print\"Introduction to heat transfer by S.K.Som, Chapter 2, Example 13\"\n", @@ -753,7 +846,15 @@ "Qinf=(h*P*k*A)**0.5*thetab\n", "print\"We see that since k is large there is significant difference between the finite length and the infinte length cases\"\n", "print\"However when the length of the rod approaches 1m,the result become almost same.\" \n", - "print\"Qinf=\",Qinf" + "print\"Qinf=\",Qinf\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n" ] }, { @@ -765,7 +866,7 @@ }, { "cell_type": "code", - "execution_count": 14, + "execution_count": 6, "metadata": { "collapsed": false }, @@ -781,6 +882,7 @@ } ], "source": [ + " \n", "import math\n", " \n", "print\"Introduction to heat transfer by S.K.Som, Chapter 2, Example 14\"\n", @@ -797,7 +899,41 @@ "#The thermal conductivity of Rod B iskB\n", "print\"The thermal conductivity of Rod B kB in W/(m*K) is \"\n", "kB=kA*(xB/xA)**2\n", - "print\"kB=\",kB" + "print\"kB=\",kB\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n" ] }, { @@ -809,7 +945,7 @@ }, { "cell_type": "code", - "execution_count": 15, + "execution_count": 7, "metadata": { "collapsed": false }, @@ -835,6 +971,7 @@ } ], "source": [ + " \n", "import math\n", " \n", "print\"Introduction to heat transfer by S.K.Som, Chapter 2, Example 15\"\n", @@ -876,7 +1013,17 @@ "#Heat loss from the plate is Qb\n", "print\"Heat loss from the plate at 400K in W is\"\n", "Qb=(N*(h*P*kal*A)**0.5*thetab*((math.cosh(m*L)-(thetaL/thetab))/(math.sinh(m*L))))+(((l*b)-(N*A))*h*thetab)+(l*b*h*thetab)\n", - "print\"Qb=\",Qb" + "print\"Qb=\",Qb\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n" ] } ], diff --git a/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter2_GK3uH9r.ipynb b/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter2_GK3uH9r.ipynb deleted file mode 100644 index ba64d857..00000000 --- a/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter2_GK3uH9r.ipynb +++ /dev/null @@ -1,1051 +0,0 @@ -{ - "cells": [ - { - "cell_type": "markdown", - "metadata": { - "collapsed": true - }, - "source": [ - "# Chapter 02:One dimensional steady-state heat conduction" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex2.1:pg-33" - ] - }, - { - "cell_type": "code", - "execution_count": 2, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 2, Example 1\n", - "The convective resistance Ro= 1/(ho*A) at the outer surface in KW**-1 is\n", - "Ro= 0.0666666666667\n", - "The conduction resistance Rs= Ls/(ks*A) of steel sheet in KW**-1 is\n", - "Rs= 8e-05\n", - "The conduction resistance Rg= Lg/(kg*A) of glass wool in KW**-1 is\n", - "Rg= 2.66666666667\n", - "The conduction resistance Rp= Lp/(kp*A) of plywood in KW**-1 is\n", - "Rp= 0.266666666667\n", - "The convective resistance Ri= 1/(hi*A) at the outer surface in KW**-1 is\n", - "Ri= 0.111111111111\n", - "The rate of heat flow Q=(To-Ti)/(Ro+Rs+Rg+Rp+Ri) in W is\n", - "Q= 12.5353919471\n", - "The temprature at the outer surface of wall is T1=To-(Q*Ro) in °C\n", - "T1= 23.1643072035\n", - "The temprature at the interface b/w steel sheet and glass wool is T2=T1-(Q*Rs) in°C\n", - "T2= 23.1633043722\n", - "The temprature at the interface b/w glass wool and plywood is T3=T2-(Q*Rg) in°C\n", - "T3= -10.2644074867\n", - "The temprature at the inner surface of wall is T4=T3-(Q*Rp)in °C\n", - "T4= -13.6071786725\n", - "Check for Ti(in °C)\n", - "The value is same as given in the problem\n", - "Ti= -15.0\n" - ] - } - ], - "source": [ - "import math\n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 2, Example 1\"\n", - "#The length of steel sheet (Ls)=1.5 mm and thermal conductivity (ks)=25 W/(mK) at the outer surface.\n", - "Ls=1.5;\n", - "ks=25;\n", - "#The length of plywood (Lp)=10 mm and thermal conductivity (kp)= .05 W/(mK) at the inner surface.\n", - "Lp=10;\n", - "kp=.05;\n", - "#The length of glass wool (Lg)=20 mm and thermal conductivity (kg)= .01W/(mK) in between steel sheet and plywood.\n", - "Lg=20;\n", - "kg=.01;\n", - "#The temprature of van inside cold Enviroment is (Ti)= -15°C while the outside surface is exposed to a surrounding ambient temprature (To)=24°C \n", - "To=24;\n", - "Ti=-15;\n", - "#The average value of heat transfer coefficients at the inner and outside surfaces of the wall are hi=12 W/(m**2*K) and ho= 20 W/(m**2*K) \n", - "hi=12;\n", - "ho=20;\n", - "#The surface area of wall (A)= .75 m**2 \n", - "A=.75;\n", - "#The convective resistance is Ro= 1/(ho*A) at the outer surface\n", - "print\"The convective resistance Ro= 1/(ho*A) at the outer surface in KW**-1 is\"\n", - "Ro=1/(ho*A)\n", - "print\"Ro=\",Ro\n", - "#The conduction resistance is Rs= Ls/(ks*A) of steel sheet\n", - "print\"The conduction resistance Rs= Ls/(ks*A) of steel sheet in KW**-1 is\"\n", - "Rs=Ls*10**-3/(ks*A)\n", - "print\"Rs=\",Rs\n", - "#The conduction resistance is Rg= Lg/(kg*A) of glass wool\n", - "print\"The conduction resistance Rg= Lg/(kg*A) of glass wool in KW**-1 is\"\n", - "Rg= Lg*10**-3/(kg*A)\n", - "print\"Rg=\",Rg\n", - "#The conduction resistance is Rp= Lp/(kp*A) of plywood\n", - "print\"The conduction resistance Rp= Lp/(kp*A) of plywood in KW**-1 is\"\n", - "Rp= Lp*10**-3/(kp*A)\n", - "print\"Rp=\",Rp\n", - "#The convective resistance is Ri= 1/(hi*A) at the outer surface\n", - "print\"The convective resistance Ri= 1/(hi*A) at the outer surface in KW**-1 is\"\n", - "Ri= 1/(hi*A)\n", - "print\"Ri=\",Ri\n", - "#The rate of heat flow is Q=(To-Ti)/(Ro+Rs+Rg+Rp+Ri)\n", - "print\"The rate of heat flow Q=(To-Ti)/(Ro+Rs+Rg+Rp+Ri) in W is\"\n", - "Q=(To-Ti)/(Ro+Rs+Rg+Rp+Ri)\n", - "print\"Q=\",Q\n", - "#The tempraure at the outer surface of wall is T1.\n", - "#The temprature at the interface b/w steel sheet and glass wool is T2.\n", - "#The temprature at the interface b/w glass wool and plywood is T3.\n", - "#The tempraure at the inner surface of wall is T4.\n", - "print\"The temprature at the outer surface of wall is T1=To-(Q*Ro) in °C\"\n", - "T1=To-(Q*Ro)\n", - "print\"T1=\",T1\n", - "print\"The temprature at the interface b/w steel sheet and glass wool is T2=T1-(Q*Rs) in°C\"\n", - "T2=T1-(Q*Rs)\n", - "print\"T2=\",T2\n", - "print\"The temprature at the interface b/w glass wool and plywood is T3=T2-(Q*Rg) in°C\"\n", - "T3=T2-(Q*Rg)\n", - "print\"T3=\",T3\n", - "print\"The temprature at the inner surface of wall is T4=T3-(Q*Rp)in °C\"\n", - "T4=T3-(Q*Rp)\n", - "print\"T4=\",T4\n", - "#Check for Ti(Temprature inside the van)\n", - "print\"Check for Ti(in °C)\"\n", - "Ti=T4-(Q*Ri)\n", - "print\"The value is same as given in the problem\"\n", - "print\"Ti=\",Ti\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - " \n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex2.2:pg-36" - ] - }, - { - "cell_type": "code", - "execution_count": 1, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 2, Example 2\n", - "The thickness of insulating material L=ki*(((Ti-To)/Q)-(Lb/kb)) in m\n", - "L= 0.056\n" - ] - } - ], - "source": [ - " \n", - "\n", - " \n", - " \n", - "import math\n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 2, Example 2\"\n", - "#The Thickness of fire clay bricks (Lb)=.2 m\n", - "Lb=0.2;\n", - "#The thermal conductivity of fire clay bricks(kb)=1.0 W/(m*K)\n", - "kb=1;\n", - "#the Thicknes of insulating material is L\n", - "#The thermal conductivity of insulating material(ki)=.07 W/(m*K)\n", - "ki=.07;\n", - "#The furnace inner brick surface is at temprature Ti=1250 K\n", - "Ti=1250;\n", - "#The furnace outer brick surface is at temprature To=310 K\n", - "To=310;\n", - "#The maximum allowable heat transfer rate(Q) from wall = 900 W/m**2\n", - "Q=900;\n", - "#Q=(Ti-To)/((Lb/kb)+(L/ki)) so L=ki*(((Ti-To)/Q)-(Lb/kb))\n", - "print\"The thickness of insulating material L=ki*(((Ti-To)/Q)-(Lb/kb)) in m\"\n", - "L=ki*(((Ti-To)/Q)-(Lb/kb))\n", - "print\"L=\",L\n" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex2.4:pg-36" - ] - }, - { - "cell_type": "code", - "execution_count": 1, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 2, Example 4\n", - "Heat transfer per unit surface area through film qf=(To-Tinf)/((1/h)+(Lf/kf))in W/(m**2)\n", - "qf= 4000.0\n", - "Heat transfer per unit surface area through substrate qs=(To-T1/(Ls/ks)in W/(m**2)\n", - "qs= 1000.0\n", - "Heat flux qo=qs+qf in W/(m**2)\n", - "qo= 5000.0\n", - "If the film is not transparent and all of the radiant heat flux is absorbed at its upper surface then\n", - "Rate of heat conduction through the film and substrate q1=(To-T1)/(Ls/ks) in W/m**2\n", - "q1= 1000.0\n", - "The temprature of the top surface of the film T2=(q1*(Lf*10**-3/kf))+To in °C\n", - "T2= 70.0\n", - "Rate of convective heat transfer from the upper surface of film to air q2=h*(T2-Tinf)in W/m**2\n", - "q2= 1250.0\n", - "Heat flux qo=q1+q2 in W/m**2 \n", - "qo= 2250.0\n" - ] - } - ], - "source": [ - " \n", - "import math\n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 2, Example 4\"\n", - "#To cure the bond at a temprature(To),a radiant source used to provide a heat flux qo W/m**2 \n", - "#The back of the substrate is maintained at a temprature T1\n", - "#The film is exposed to air at a temprature (Tinf)\n", - "#the convective heat transfer coefficient is h.\n", - "#Given To=60°C,Tinf=20°C,h=25 W/(m**K)and T1=30°C\n", - "To=60;\n", - "Tinf=20;\n", - "h=25;\n", - "T1=30;\n", - "#Ls is the thickness of substrate and Lf is thickness of film in mm.\n", - "Ls=1.5;\n", - "Lf=.25;\n", - "#kf and ks are thermal conductivity of film and substrate respectively in W/(m*K)\n", - "kf=.025;\n", - "ks=.05;\n", - "#qo is Heat flux.\n", - "#qo=qf+qs where qf and qs are rate of heat transfer per unit surface area through the film and the substrate respectively.\n", - "print\"Heat transfer per unit surface area through film qf=(To-Tinf)/((1/h)+(Lf/kf))in W/(m**2)\"\n", - "qf=(To-Tinf)/((1/h)+(Lf*10**-3/kf))\n", - "print\"qf=\",qf\n", - "print\"Heat transfer per unit surface area through substrate qs=(To-T1/(Ls/ks)in W/(m**2)\"\n", - "qs=(To-T1)/(Ls*10**-3/ks)\n", - "print\"qs=\",qs\n", - "print\"Heat flux qo=qs+qf in W/(m**2)\"\n", - "qo=qs+qf\n", - "print\"qo=\",qo\n", - "#If the film is not transparent and all of the radiant heat flux is absorbed at its upper surface then qo=q1+q2\n", - "#q1 is rate of heat conduction through the film and substrate\n", - "#q2 is rate of convective heat transfer from the upper surface of film to air\n", - "print\"If the film is not transparent and all of the radiant heat flux is absorbed at its upper surface then\"\n", - "print\"Rate of heat conduction through the film and substrate q1=(To-T1)/(Ls/ks) in W/m**2\"\n", - "q1=(To-T1)/(Ls*10**-3/ks)\n", - "print\"q1=\",q1\n", - "#To determine q2 we need to find the temprature(T2) of the top surface \n", - "print\"The temprature of the top surface of the film T2=(q1*(Lf*10**-3/kf))+To in °C\"\n", - "T2=(q1*(Lf*10**-3/kf))+To\n", - "print\"T2=\",T2\n", - "print\"Rate of convective heat transfer from the upper surface of film to air q2=h*(T2-Tinf)in W/m**2\"\n", - "q2=h*(T2-Tinf)\n", - "print\"q2=\",q2\n", - "print\"Heat flux qo=q1+q2 in W/m**2 \"\n", - "qo=q1+q2\n", - "print\"qo=\",qo\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex2.6:pg-38" - ] - }, - { - "cell_type": "code", - "execution_count": 6, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - " Introduction to heat transfer by S.K.Som, Chapter 2, Example 6\n", - "(a)The expression for the temprature distribution in the plate T=160+2*10**3*(x-100*x**2)\n", - "(b)The maximum temprature occurs at x=5mm or 0.005m away from the left surface towards the right\n", - "The maximum temprature(Tmax) in °C is\n", - "Tmax= 165.0\n", - "(c(i))The rate of heat transfer at the left face in MW/m**2 is\n", - "Q= -1\n", - "The minus sign indicates that the heat flow in the negative direction\n", - "(c(ii))The rate of heat transfer at the right face in MW/m**2 is\n", - "Q= 1.2\n", - "The minus sign for (q/A)@x=0 and the plus sign for (q/A)@x=0.02 indicates that heat is lost from both the surfaces to surroundings\n", - "(c(iii))The rate of heat transfer at the centre in MW/m**2 is\n", - "Q= 0.4\n" - ] - } - ], - "source": [ - " \n", - "import math\n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 2, Example 6\"\n", - "#The thickness of plate 20mm or .02m with uniform heat generation qg=80MW/m**3\n", - "#The thermal conductivity of wall(k)is 200W/m*K.\n", - "k=200;\n", - "#The left and right faces are kept at tempratures T=160°C and T=120°C respectively\n", - "#We start with the equation (d**2T/dx**2)+(qg/k)=0 or T=-(qg/2k)*x**2 +(c1*x)+c2 \n", - "#With qg=80*10**6W/m**3 and k=200W/(m*K)\n", - "#Applying boundary condition at x=0,T=160°C and x=0.02,T=120°C we get constant c2=160°C and c2=2000m**-1\n", - "#Hence T=160+2*10**3*(x-100*x**2)----->eq.1\n", - "print\"(a)The expression for the temprature distribution in the plate T=160+2*10**3*(x-100*x**2)\" \n", - "#For maximum temprature differentiating eq.1 with respect to x and equating it to zero...we get dT/dx=(2*10**3)-(4*10**5*x)=0,which gives x=0.005m=5mm\n", - "print\"(b)The maximum temprature occurs at x=5mm or 0.005m away from the left surface towards the right\"\n", - "x=0.005;\n", - "#The maximum temprature is Tmax\n", - "print\"The maximum temprature(Tmax) in °C is\"\n", - "Tmax=160+2*10**3*(x-100*x**2)\n", - "print\"Tmax=\",Tmax\n", - "#The rate of heat transfer(q/A) is given by -k*(dT/dx)\n", - "#Let dT/dx=X and (q/A)=Q\n", - "print\"(c(i))The rate of heat transfer at the left face in MW/m**2 is\"\n", - "#For left face x=0\n", - "x=0;\n", - "X=(2*10**3)-(4*10**5*x);\n", - "Q=-k*X/10**6\n", - "print\"Q=\",Q\n", - "print\"The minus sign indicates that the heat flow in the negative direction\"\n", - "print\"(c(ii))The rate of heat transfer at the right face in MW/m**2 is\"\n", - "#For right face x=0.02\n", - "x=0.02;\n", - "X=(2*10**3)-(4*10**5*x);\n", - "Q=-k*X/10**6\n", - "print\"Q=\",Q\n", - "#(q/A)@x=0 implies rate of heat transfer at the position where x=0. \n", - "print\"The minus sign for (q/A)@x=0 and the plus sign for (q/A)@x=0.02 indicates that heat is lost from both the surfaces to surroundings\"\n", - "print\"(c(iii))The rate of heat transfer at the centre in MW/m**2 is\"\n", - "#For centre x=0.01\n", - "x=0.01;\n", - "X=(2*10**3)-(4*10**5*x);\n", - "Q=-k*X/10**6\n", - "#A check for the above results can be made from an energy balance of the plate as |(q/A)|@x=0+|(q/A)|@x=0.02=qG*0.02\n", - "print\"Q=\",Q\n", - "\n", - "\n" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex2.9:pg- 48" - ] - }, - { - "cell_type": "code", - "execution_count": 2, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 2, Example 9\n", - "The critical thickness of insulation in metre is\n", - "X= 0.182340462632\n", - "The heat transfer rate Q per metre of tube length in W/m is \n", - "Q= 26.807459995\n", - "X= 0.559673817307\n", - "The heat transfer rate per metre of tube length Q in W/m is \n", - "Q= 28.1996765363\n", - "X= 1.79194526577\n", - "The heat transfer rate per metre of tube length Q in W/m is \n", - "Q= 21.1086798197\n" - ] - } - ], - "source": [ - " \n", - "import math\n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 2, Example 9\"\n", - "#A thin walled copper tube of outside metal radius r=0.01m carries steam at temprature, T1=400K.It is inside a room where the surrounding air temprature is Tinf=300K.\n", - "T1=400;\n", - "Tinf=300;\n", - "r=0.01;\n", - "#The tube is insulated with magnesia insulation of an approximate thermal conductivity of k=0.07W/(m*K)\n", - "k=0.07;\n", - "#External convective Coefficient h=4W/(m**2*K)\n", - "h=4;\n", - "#Critical thickness(rc) is given by k/h\n", - "print\"The critical thickness of insulation in metre is\"\n", - "rc=k/h\n", - "#We use the rate of heat transfer per metre of tube length as Q=(Ti-Tinf)/((ln(r2/r1)/(2*math.pi*L*k))+(1/(h*2*math.pi*r2*L))) where length,L=1m\n", - "L=1;\n", - "#When 0.002m thick layer of insulation r1=0.01m,r2=0.01+0.002=0.012m\n", - "r1=0.01;#inner radius\n", - "r2=0.012;#outer radius\n", - "#Let ln(r2/r1)=X\n", - "X=math.log(r2/r1)/math.log(2.718);\n", - "print\"X=\",X\n", - "#The heat transfer rate per metre of tube length is Q\n", - "print\"The heat transfer rate Q per metre of tube length in W/m is \"\n", - "Q=(T1-Tinf)/(((X)/(2*math.pi*L*k))+(1/(h*2*math.pi*r2*L)))\n", - "print\"Q=\",Q\n", - "#When critical thickness of insulation r1=0.01m,r2=0.0175m\n", - "r2=0.0175;#outer radius\n", - "r1=0.01;#inner radius\n", - "#Let ln(r2/r1)=X\n", - "X=math.log(r2/r1)/math.log(2.718);\n", - "print\"X=\",X\n", - "#The heat transfer rate per metre of tube length is Q \n", - "print\"The heat transfer rate per metre of tube length Q in W/m is \"\n", - "Q=(T1-Tinf)/(((X)/(2*math.pi*L*k))+(1/(h*2*math.pi*r2*L)))\n", - "print\"Q=\",Q\n", - "#When there is a 0.05 m thick layer of insulation r1=0.01m,r2=.01+0.05=0.06m\n", - "r1=0.01;#inner radius\n", - "r2=0.06;#outer radius\n", - "#Let ln(r2/r1)=X\n", - "X=math.log(r2/r1)/math.log(2.718);\n", - "print\"X=\",X\n", - "#The heat transfer rate per metre of tube length is Q \n", - "print\"The heat transfer rate per metre of tube length Q in W/m is \"\n", - "Q=(T1-Tinf)/(((X)/(2*math.pi*L*k))+(1/(h*2*math.pi*r2*L)))\n", - "#It is important to note that Q increases by 5.2% when the insulation thickness increases from 0.002m to critical thickness. \n", - "#Addition of insulation beyond the critical thickness decreases the value of Q (The heat loss).\n", - "print\"Q=\",Q\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex2.10:pg-49" - ] - }, - { - "cell_type": "code", - "execution_count": 3, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 2, Example 10\n", - "the thickness of insulation in metre is\n", - "t= 0.019\n" - ] - } - ], - "source": [ - " \n", - "import math\n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 2, Example 10\"\n", - "#A copper pipe having 35mm outer diameter(Do) and 30mm inner diameter(Di) carries liquid oxygen to the storage site of a space shuttle at temprature,T1=-182°C\n", - "#mass flow rate is ,mdot=0.06m**3/min. \n", - "Di=0.03;#in metre\n", - "Do=0.035;# in metre\n", - "T1=-182;\n", - "mdot=0.06;\n", - "#The ambient air is at temprature(Ta)=20°C and has a dew point(T3)=10°C.\n", - "Ta=20;\n", - "T3=10;\n", - "#The thermal conductivity(k) of insulating material is 0.02W/(m*k)\n", - "k=0.02;\n", - "#The convective heat transfer coefficient on the outside is h=17W/(m**2*K)\n", - "h=17;\n", - "#The thermal conductivity of copper kcu=400W/(m*K)\n", - "kcu=400;\n", - "#We can write Q=((Ta-T1)/(R1+R2+R3))=((Ta-T3)/(R3)),Rearranging we get ((R1+R2+R3)/(R3))=((Ta-T1)/(Ta-T3))--------eq.1\n", - "#The conduction Resistance of copper pipe(R1)=ln(0.035/0.03)/(2*math.pi*L*kcu)=3.85*10**-4/(2*math.pi*L)K/W\n", - "#The conduction resistance of insulating material (R2)=ln(r3/0.035)/(2*math.pi*L*k)=(1/(2*math.pi*L))((50*ln(r3/0.035)))K/W where r3 is the outer radius of insulation in metres.\n", - "#The convective resistance at the outer surface(R3)=1/(2*math.pi*L*h*r3)=(1/2*math.pi*L)*(mdot/r3)K/W\n", - "#Substituting the values in eq.1 we have 1+((50*ln(r3/0.035)+(3.85*10**-4))/(mdot/r3))=20-(-182)/(20-10)\n", - "#A rearrangement of the above equation gives r3*ln(r3)+3.35*r3=0.023\n", - "#The equation is solved by trial and error method which finally gives r3=0.054m\n", - "r3=0.054;#outer radius of insulation\n", - "#Therefore the thickness of insulation is given by t=r3-Do\n", - "print\"the thickness of insulation in metre is\"\n", - "t=r3-Do\n", - "print\"t=\",t\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex2.11:pg-52" - ] - }, - { - "cell_type": "code", - "execution_count": 4, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 2, Example 11\n", - "The rate of heat generation of thermal energy in W/m**3 is\n", - "qG= 407436654.315\n", - "The temprature of wire at the centre in K is \n", - "To= 656.631455962\n" - ] - } - ], - "source": [ - " \n", - "import math\n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 2, Example 11\"\n", - "#An electrical resistance wire 2.5mm or 2.5*10**-3m in diameter(D) and L=0.5m long has a measured voltage drop of E=25V for a current flow of I=40A.\n", - "D=2.5*10**-3;\n", - "I=40;\n", - "E=25;\n", - "L=0.5;\n", - "ro=D/2;#ro is radius of wire\n", - "#The thermal conductivity(k) of wire material is 24W/(m*K) \n", - "k=24;\n", - "#The rate of generation of thermal energy per unit volume is given by qG=(E*I)/(L*math.pi*D**2/4)\n", - "print\"The rate of heat generation of thermal energy in W/m**3 is\"\n", - "qG=(E*I)/(L*math.pi*D**2/4)\n", - "print\"qG=\",qG\n", - "#The temprature at the centre is given by To=Tw+((qG*ro**2)/(4*k)) where Tw=650K is surface temprature \n", - "Tw=650;\n", - "print\"The temprature of wire at the centre in K is \"\n", - "To=Tw+((qG*ro**2)/(4*k))\n", - "#Note:The answer in the book is incorrect(value of D has been put instead of ro)\n", - "print\"To=\",To\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex2.12:pg-56" - ] - }, - { - "cell_type": "code", - "execution_count": 10, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 2, Example 12\n", - "The inner(A1) and outer surfaces(A2) areas of the tank in m**2 are\n", - "The convective resistance(Ri) at the inner surface in K/W is \n", - "Ri= 0.000159154943092\n", - "The conduction resistance(Rs)of the tank in K/W is\n", - "Rs= 0.0\n", - "The convective resistance(Roc) at the outer surface in K/W is\n", - "Roc= 0.00127323954474\n", - "The radiative heat transfer coefficient hr in W/(m**2*K) is\n", - "hr= 5.26265474661\n", - "Therefore the radiative resistance(Ror) at the outer surface in K/W is\n", - "Ror= 0.00241938642385\n", - "The equivalent resistance in K/W is\n", - "Ro= 0.000834218925785\n", - "The total resistance in K/W is\n", - "Rtotal= 0.000993373868877\n", - "The rate of heat transfer,Q in W is\n", - "Q= 20133.406592\n", - "The outer surface temprature in °C is\n", - "T2= 3.2043311804\n", - "which is sufficiently close to the assumption.So there is no need of further iteration\n", - "The total heat transfer(Qt) during a 24-hour period in KJ is\n", - "Qt= 1739526.32955\n", - "Therefore,the amount of ice(mice)in kG which melts during a 24 hour period is\n", - "mice= 5208.16266333\n" - ] - } - ], - "source": [ - "\n", - " \n", - " \n", - " \n", - "import math\n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 2, Example 12\"\n", - "#A spherical tank of internal diameter, Di=5m ,made of t=25mm thick stainless steel(thermal conductivity,k=15W/(m*K)),is used to store water at temprature(Ti)=0°C.Do is outer diameter\n", - "Di=5;\n", - "t=25;\n", - "Do=5+2*(t/1000);#in metre\n", - "k=15;\n", - "Ti=0;\n", - "#The tank is located in a room whose temprature is (To)=20°C.\n", - "To=20;\n", - "#Emmisivity is 1.\n", - "#The convection heat transfer coefficients at the inner and outer surfaces of the tank are hi=80W/(m**2*K) and ho=10W/(m**2*K)\n", - "hi=80;\n", - "ho=10;\n", - "#The heat of fusion of ice at atmospheric pressure is deltahf=334kJ/kg.The stefan-boltzman constant(sigma) is 5.67*10**-8W/m**2.\n", - "sigma=5.67*10**-8;\n", - "deltahf=334;\n", - "#The inner surface area is (A1) and outer surface area is (A2)of the tank\n", - "print\"The inner(A1) and outer surfaces(A2) areas of the tank in m**2 are\"\n", - "A1=math.pi*Di**2\n", - "A2=math.pi*Do**2\n", - "#The individual thermal resistances can be determined as\n", - "#The convective resistance is (Ri)\n", - "print\"The convective resistance(Ri) at the inner surface in K/W is \"\n", - "Ri=1/(hi*A1)\n", - "print\"Ri=\",Ri\n", - "#The conduction resistance is(Rs)\n", - "print\"The conduction resistance(Rs)of the tank in K/W is\"\n", - "Rs=(Do-Di)/(2*k*math.pi*Di*Do)\n", - "print\"Rs=\",Rs\n", - "#The convective resistance is(Roc)\n", - "print\"The convective resistance(Roc) at the outer surface in K/W is\"\n", - "Roc=1/(ho*A2)\n", - "print\"Roc=\",Roc\n", - "#The radiative resistance(Ror) at the outer surface is Ror=1/(A2*hr) \n", - "#The radiative heat transfer coefficient hr is determined by hr=sigma*(T2**2+293.15**2)*(T2+293.15)\n", - "#But we do not know the outer surface temprature T2 of the tank and hence we cannot determine the value of hr.\n", - "#Therfore we adopt an iterative procedure.We assume T2=4°C=277.15K.Putting the value in hr=sigma*(T2**2+293.15**2)*(T2+293.15) we get\n", - "T2=277.15;\n", - "print\"The radiative heat transfer coefficient hr in W/(m**2*K) is\"\n", - "hr=sigma*(T2**2+293.15**2)*(T2+293.15)\n", - "print\"hr=\",hr\n", - "print\"Therefore the radiative resistance(Ror) at the outer surface in K/W is\"\n", - "Ror=1/(A2*hr)\n", - "print\"Ror=\",Ror\n", - "#The two parallel resistances Roc and Ror can be replaced by an equivalent resistance Ro as X=(1/Ro)=(1/Roc)+(1/Ror)\n", - "print\"The equivalent resistance in K/W is\"\n", - "X=(1/Roc)+(1/Ror);\n", - "Ro=1/X\n", - "print\"Ro=\",Ro\n", - "#Now the resistance Ri,Rs and Ro are in series an hence the total resistance becomes Rtotal=Ri+Rs+Ro \n", - "print\"The total resistance in K/W is\"\n", - "Rtotal=Ri+Rs+Ro \n", - "print\"Rtotal=\",Rtotal\n", - "#The rate of heat transfer is given by Q=(To-Ti)/Rtotal\n", - "print\"The rate of heat transfer,Q in W is\"\n", - "Q=(To-Ti)/Rtotal\n", - "print\"Q=\",Q\n", - "#The outer surface(T2) is calculated as T2=To-Q*Ro\n", - "print\"The outer surface temprature in °C is\"\n", - "T2=To-Q*Ro\n", - "print\"T2=\",T2\n", - "print\"which is sufficiently close to the assumption.So there is no need of further iteration\"\n", - "#The total heat transfer is (Qt),during a 24-hour period\n", - "print\"The total heat transfer(Qt) during a 24-hour period in KJ is\"\n", - "Qt=Q*24*3600/1000\n", - "print\"Qt=\",Qt\n", - "#the amount of ice in kG which melts during a 24 hour period is (mice)\n", - "print\"Therefore,the amount of ice(mice)in kG which melts during a 24 hour period is\"\n", - "mice=Qt/deltahf\n", - "print\"mice=\",mice\n", - "\n", - "\n", - "\n", - "\n", - "\n" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex2.13:pg-68" - ] - }, - { - "cell_type": "code", - "execution_count": 5, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 2, Example 13\n", - "P/A in m**-1 is\n", - "X= 400.0\n", - "m in m**-1 is\n", - "m= 3.28797974611\n", - "M in W/K is\n", - "M= 0.0955478103936\n", - "thetab in °C is \n", - "thetab= 100\n", - "Heat loss from rod in Watt, for different value of length(in m) is \n", - "Q= 0.705573384326\n", - "Q= 1.32655528327\n", - "Q= 2.53006298798\n", - "Q= 5.56299390901\n", - "Q= 8.29001416681\n", - "Q= 9.45769063154\n", - "Q= 9.52862252977\n", - "Q= 9.55478103936\n", - "For an infintely long rod heat loss in W is\n", - "We see that since k is large there is significant difference between the finite length and the infinte length cases\n", - "However when the length of the rod approaches 1m,the result become almost same.\n", - "Qinf= 9.55478103936\n" - ] - } - ], - "source": [ - " \n", - "import math\n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 2, Example 13\"\n", - "#A very long,10mm diameter(D) copper rod(thermal conductivity,k=370W/(m*K))is exposed to an enviroment at temprature,Tinf=20°C.\n", - "D=0.01;\n", - "k=370;\n", - "Tinf=20;\n", - "#The base temprature of the radius maintained at Tb=120°C.\n", - "Tb=120;\n", - "#The heat transfer coefficient between the rod and the surrounding air is h=10W/(m*K**2)\n", - "h=10;\n", - "#The rate of heat transfer for all finite lengths will be given by P/A=(4*pi*D)/(pi*D**2)\n", - "#Let P/A=X\n", - "print\"P/A in m**-1 is\"\n", - "X=(4*math.pi*D)/(math.pi*D**2)\n", - "print\"X=\",X\n", - "#m is defined as ((h*p)/(k*A)]**0.5 \n", - "print\"m in m**-1 is\"\n", - "m=(h*X/k)**0.5\n", - "print\"m=\",m\n", - "#Let Y=h/(m*k)\n", - "Y=h/(m*k)\n", - "#Let M=(h*P*k*A)**0.5\n", - "P=(math.pi*D);#perimeter of the rod\n", - "A=(math.pi*D**2)/4;#Area of the rod\n", - "print\"M in W/K is\"\n", - "M=(h*P*k*A)**0.5\n", - "print\"M=\",M\n", - "#thetab is the parameter that defines the base temprature\n", - "print\"thetab in °C is \"\n", - "thetab=Tb-Tinf\n", - "print\"thetab=\",thetab\n", - "#Heat loss from the rod is defined as Q=(h*P*k*A)*thetab*(((h/m*k)+math.tanh(m*L)]/(1+(h/m*k)*math.tanh(m*L)]}\n", - "print\"Heat loss from rod in Watt, for different value of length(in m) is \"\n", - "L=0.02#Length of rod\n", - "Q=M*thetab*(((Y)+math.tanh(m*L))/(1+(Y)*math.tanh(m*L)))\n", - "print\"Q=\",Q\n", - "L=0.04#length of rod\n", - "Q=M*thetab*(((Y)+math.tanh(m*L))/(1+(Y)*math.tanh(m*L)))\n", - "print\"Q=\",Q\n", - "L=0.08#length of rod\n", - "Q=M*thetab*(((Y)+math.tanh(m*L))/(1+(Y)*math.tanh(m*L)))\n", - "print\"Q=\",Q\n", - "L=0.20#length of rod\n", - "Q=M*thetab*(((Y)+math.tanh(m*L))/(1+(Y)*math.tanh(m*L)))\n", - "print\"Q=\",Q\n", - "L=0.40#length of rod\n", - "Q=M*thetab*(((Y)+math.tanh(m*L))/(1+(Y)*math.tanh(m*L)))\n", - "print\"Q=\",Q\n", - "L=0.80#length of rod\n", - "Q=M*thetab*(((Y)+math.tanh(m*L))/(1+(Y)*math.tanh(m*L)))\n", - "print\"Q=\",Q\n", - "L=1.00#length of rod\n", - "Q=M*thetab*(((Y)+math.tanh(m*L))/(1+(Y)*math.tanh(m*L)))\n", - "print\"Q=\",Q\n", - "L=10.00#length of rod\n", - "Q=M*thetab*(((Y)+math.tanh(m*L))/(1+(Y)*math.tanh(m*L)))\n", - "print\"Q=\",Q\n", - "#For an infinitely long rod we use heat loss as ,Qinf=(h*P*k*A)**0.5*thetab\n", - "print\"For an infintely long rod heat loss in W is\"\n", - "Qinf=(h*P*k*A)**0.5*thetab\n", - "print\"We see that since k is large there is significant difference between the finite length and the infinte length cases\"\n", - "print\"However when the length of the rod approaches 1m,the result become almost same.\" \n", - "print\"Qinf=\",Qinf\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex2.14:pg-81" - ] - }, - { - "cell_type": "code", - "execution_count": 6, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 2, Example 14\n", - "The thermal conductivity of Rod B kB in W/(m*K) is \n", - "kB= 18.0\n" - ] - } - ], - "source": [ - " \n", - "import math\n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 2, Example 14\"\n", - "#Considering two very long slender rods of the same diameter but of different materials.\n", - "#The base of each rod is maintained at 100°C while the surfaces of the rod are exposed to 20°C\n", - "#By traversing length of each rod with a thermocouple it was observed that tempratures of rod were equal at the position xA=0.15m and xB=0.075 from base.\n", - "xA=0.15;\n", - "xB=0.075;\n", - "#Thermal conductivity of rod A is known to be kA=72 W/(m*K)\n", - "kA=72;\n", - "#In case of a very long slender rod we use the tip boundary condition thetaL=0 as L--->infinity\n", - "#Therfore we can write for the locations where the tempratures are equal thetab*e**(-mA*xA)=thetab*e**(-mB*xB) or xA/xB=mB/mA,Again mB/mA=(kA/kB)**0.5\n", - "#So kB=kA*(xB/xA)**2\n", - "#The thermal conductivity of Rod B iskB\n", - "print\"The thermal conductivity of Rod B kB in W/(m*K) is \"\n", - "kB=kA*(xB/xA)**2\n", - "print\"kB=\",kB\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex2.15:pg-83" - ] - }, - { - "cell_type": "code", - "execution_count": 7, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 2, Example 15\n", - " perimeter of each fin in m is\n", - "P= 0.202\n", - "Cross sectional area of fin in m**2 is\n", - "A= 0.0001\n", - "M= 0.834805366538\n", - "m= 36.2958855016\n", - "Temprature parameter at fin base in K is\n", - "thetab= 100\n", - "Fixed temprature at fin tip in K is\n", - "thetaL= 50\n", - "Heat loss from the plate at 400K in W is\n", - "Qb= 13028.1662009\n" - ] - } - ], - "source": [ - " \n", - "import math\n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 2, Example 15\"\n", - "#A stack that is b=300mm wide and l=100mm deep contains N=60 fins each of length L=12mm.\n", - "L=0.012;#in metre\n", - "b=0.3;#in metre\n", - "l=0.1;#in metre\n", - "N=60;\n", - "#The entire stack is made of aluminum which is everywhere t=1.0 mm thick.\n", - "t=0.001;#in metre\n", - "#The temprature limitations associated with electrical components are Tb=400K and TL=350K.\n", - "#Tb is base temprature and TL is end temprature\n", - "Tb=400;\n", - "TL=350; \n", - "#Given convection heat transfer coefficient(h=150W/(m**2*K)),Surrounding Temprature(Tinf=300K),thermal conductivity of aluminium(kaluminium=230W/(m*K))\n", - "h=150;\n", - "Tinf=300;\n", - "kal=230;\n", - "#Here both the ends of the fins are at fixed tempratures .Therefore we use M=(h*P*k*A)**0.5 and m=((h*P)/(k*A))**0.5,thetab=Tb-Tinf,thetaL=TL-Tinf\n", - "#from the given data perimeter of each fin is given by P= 2*(l+t)in m and area of each fin is A=t*l\n", - "print\" perimeter of each fin in m is\"\n", - "P= 2*(l+t)\n", - "print\"P=\",P\n", - "print\"Cross sectional area of fin in m**2 is\"\n", - "A=t*l\n", - "print\"A=\",A\n", - "#M is defined as (h*P*kal*A)**0.5 and m is defined as ((h*P)/(kal*A))**0.5\n", - "M=(h*P*kal*A)**0.5\n", - "m=((h*P)/(kal*A))**0.5\n", - "print\"M=\",M\n", - "print\"m=\",m\n", - "#thetab and thetaL are the parameters that define the fin tempratures at base and tip respectively.\n", - "print\"Temprature parameter at fin base in K is\"\n", - "thetab=Tb-Tinf\n", - "print\"thetab=\",thetab\n", - "print\"Fixed temprature at fin tip in K is\"\n", - "thetaL=TL-Tinf\n", - "print\"thetaL=\",thetaL\n", - "#Heat loss from the plate is Qb\n", - "print\"Heat loss from the plate at 400K in W is\"\n", - "Qb=(N*(h*P*kal*A)**0.5*thetab*((math.cosh(m*L)-(thetaL/thetab))/(math.sinh(m*L))))+(((l*b)-(N*A))*h*thetab)+(l*b*h*thetab)\n", - "print\"Qb=\",Qb\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n" - ] - } - ], - "metadata": { - "kernelspec": { - "display_name": "Python 2", - "language": "python", - "name": "python2" - }, - "language_info": { - "codemirror_mode": { - "name": "ipython", - "version": 2 - }, - "file_extension": ".py", - "mimetype": "text/x-python", - "name": "python", - "nbconvert_exporter": "python", - "pygments_lexer": "ipython2", - "version": "2.7.11" - } - }, - "nbformat": 4, - "nbformat_minor": 0 -} diff --git a/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter3.ipynb b/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter3.ipynb index 6b51de29..55a11dc9 100644 --- a/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter3.ipynb +++ b/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter3.ipynb @@ -34,6 +34,9 @@ } ], "source": [ + "\n", + "\n", + " \n", "import math\n", " \n", "print\"Introduction to heat transfer by S.K.Som, Chapter 3, Example 1\"\n", @@ -56,7 +59,7 @@ "#Temperature in degree celcius\n", "print\"Temperature at the centre in Degree C is\"\n", "T = theta*100+100\n", - "print\"T=\",T" + "print\"T=\",T\n" ] }, { @@ -87,6 +90,9 @@ } ], "source": [ + " \n", + " \n", + " \n", "import math\n", " \n", "print\"Introduction to heat transfer by S.K.Som, Chapter 3, Example 2\"\n", @@ -111,7 +117,7 @@ "print\"theta=\",theta\n", "print\"Temperature in K at centre point\"\n", "T = theta*100+300\n", - "print\"T=\",T" + "print\"T=\",T\n" ] }, { @@ -160,6 +166,7 @@ } ], "source": [ + " \n", "import math\n", "import numpy\n", " \n", @@ -206,7 +213,7 @@ "print T7\n", "print\"T8 in degree K\"\n", "T8 = T[7]\n", - "print T8" + "print T8\n" ] }, { @@ -248,6 +255,7 @@ } ], "source": [ + " \n", "import math\n", "import numpy\n", " \n", @@ -292,7 +300,7 @@ "print T5\n", "print\"T6 in degree C\"\n", "T6 = T[4]\n", - "print T6" + "print T6\n" ] }, { @@ -346,6 +354,7 @@ } ], "source": [ + " \n", "import math\n", " \n", "print\"Introduction to heat transfer by S.K.Som, Chapter 3, Example 6\"\n", @@ -403,7 +412,7 @@ "print T8\n", "print\"T9 in degree C\"\n", "T9 = T[8]\n", - "print T9" + "print T9\n" ] } ], diff --git a/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter3_18OmDFC.ipynb b/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter3_18OmDFC.ipynb deleted file mode 100644 index 55a11dc9..00000000 --- a/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter3_18OmDFC.ipynb +++ /dev/null @@ -1,440 +0,0 @@ -{ - "cells": [ - { - "cell_type": "markdown", - "metadata": { - "collapsed": true - }, - "source": [ - "# Chapter 03:Multidimensional steady-state heat conduction" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex3.1:pg-92" - ] - }, - { - "cell_type": "code", - "execution_count": 1, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 3, Example 1\n", - "Temperature at the centre in Degree C is\n", - "T= 125.371641666\n" - ] - } - ], - "source": [ - "\n", - "\n", - " \n", - "import math\n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 3, Example 1\"\n", - "#Length and breadth is given as 1 unit (Gemoetry is Square)\n", - "L = 1;#length\n", - "#Problem can be divided into two modules\n", - "#Solution to module 1 is given by Eq. 3.21, considering the first three terms\n", - "#n is the looping parameter\n", - "#theta is the non dimensional temperature defined as ((T-100)/100) where T is actual temperature in degree Celcius.\n", - "#Initialising theta as zero\n", - "theta = 0;\n", - "for n in range(1,3):\n", - " theta = theta+((2/math.pi)*((math.sin((n*math.pi)/2)*math.sinh((n*math.pi)/2))*((-1)**(n+1)+1)))/(n*math.sinh(n*math.pi));\n", - " \n", - "#Solution to module 2 is given by Eq. 3.24, considering the first three terms\n", - "for n in range(1,3):\n", - " theta2 = theta+(((3*2)/math.pi)*((math.sin((n*math.pi)/2)*math.sinh((n*math.pi)/2))*((-1)**(n+1)+1)))/(n*math.sinh(n*math.pi));\n", - " \n", - "#Calculating value of temperature from the value of theta\n", - "#Temperature in degree celcius\n", - "print\"Temperature at the centre in Degree C is\"\n", - "T = theta*100+100\n", - "print\"T=\",T\n" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex3.2:pg-94" - ] - }, - { - "cell_type": "code", - "execution_count": 2, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - " Introduction to heat transfer by S.K.Som, Chapter 3, Example 2\n", - "Steady state non dimensional temperature is\n", - "theta=2*math.sinh(pi*y/a)*math.sin(pi*x/a)/(math.sinh(pi)) + math.sinh(pi*x/a)*math.sin(pi*y/a)/(math.sinh(pi))\n", - "theta= 0.597805223008\n", - "Temperature in K at centre point\n", - "T= 359.780522301\n" - ] - } - ], - "source": [ - " \n", - " \n", - " \n", - "import math\n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 3, Example 2\"\n", - "#Temperature in K at four edges are given\n", - "#Theta is non dimensional temperature defined as ((T-300)/100) where T is actual temperature in K.\n", - "#Given length as well as the breadth of square plate is ''a''\n", - "#Problem can be divided into two modules\n", - "#Solution to module 1 is given by Eq. 3.23\n", - "#Solution of first module is non dimensional temperature theta1\n", - "#theta1=2*math.sinh(pi*y/a)*math.sin(pi*x/a)/(math.sinh(pi))\n", - "#Solution to module 2 is given by Eq. 3.24\n", - "#Solution of second module is non dimensional temperature theta2\n", - "#theta2=math.sinh(pi*x/a)*math.sin(pi*y/a)/(math.sinh(pi))\n", - "#Therefore\n", - "print\"Steady state non dimensional temperature is\"\n", - "print\"theta=2*math.sinh(pi*y/a)*math.sin(pi*x/a)/(math.sinh(pi)) + math.sinh(pi*x/a)*math.sin(pi*y/a)/(math.sinh(pi))\"\n", - "#At the centre, x coordinate and y coordinate in unit are\n", - "#x=a/2, y=a/2\n", - "#Non dimensional temperature at centre point\n", - "theta = (2*math.sinh(math.pi/2))/math.sinh(math.pi)+math.sinh(math.pi/2)/math.sinh(math.pi);\n", - "#Temperature in K at centre point\n", - "print\"theta=\",theta\n", - "print\"Temperature in K at centre point\"\n", - "T = theta*100+300\n", - "print\"T=\",T\n" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex3.3:pg-96" - ] - }, - { - "cell_type": "code", - "execution_count": 14, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 3, Example 3\n", - "Temperatures at nodal points in degree K\n", - "T1 in degree K\n", - "[ 398.67699539 155.83601706 66.53320567 119.43598224 79.06693359\n", - " 40.99573505 14.15266777 9.19140047]\n", - "T2 in degree K\n", - "[ 77.91800853 232.60510053 92.0706763 39.53346679 80.21585865\n", - " 48.72486726 19.11393507 11.30646706]\n", - "T3 in degree K\n", - "[ 33.26660284 92.0706763 237.56636783 20.49786753 48.72486726\n", - " 82.33092523 46.76647228 21.51623292]\n", - "T4 in degree K\n", - "[ 14.15266777 38.22787014 93.53294456 9.19140047 22.61293411\n", - " 43.03246584 124.91948821 27.99199234]\n", - "T5 in degree K\n", - "[-0. -0. -0. -0. -0. -0. -0. -0.]\n", - "T6 in degree K\n", - "[-0. -0. -0. -0. -0. -0. -0. -0.]\n", - "T7 in degree K\n", - "[ 95.65671512 227.3827139 384.21098442 77.62207329 214.83157803\n", - " 554.32152494 100.40908695 109.12176865]\n", - "T8 in degree K\n", - "[ 24.51040125 60.30115763 114.75324223 18.87022369 50.97049352\n", - " 124.71059274 74.64531291 166.55931761]\n" - ] - } - ], - "source": [ - " \n", - "import math\n", - "import numpy\n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 3, Example 3\"\n", - "#internodal distance in x direction in m\n", - "deltax = 1.0/4;\n", - "#internodal distance in y direction in m\n", - "deltay = 1.0/4;\n", - "#Air temperature in degree K\n", - "Tinfinity = 400;\n", - "#Heat transfer coefficient in W/(m**2*K)\n", - "h = 10;\n", - "#T1, T2, T3, T4, T5, T6, T7, T8 are nodal temperatures in degree K.\n", - "#T is the temperature matrix and is transpose of [T1 T2 T3 T4 T5 T6 T7 T8]\n", - "#using Nodal Equations, we have Coefficeint Matrix A as\n", - "A = [[-4,1,0,0,1,0,0,0],[1,-4,1,0,0,1,0,0],[0,1,-4,1,0,0,1,0],[2,0,0,0,-4,1,0,0],[0,2,0,0,1,-4,1,0],[0,0,2,0,0,1,-4,1],[0,0,2,-6,0,0,0,1],[0,0,0,2,0,0,2,-6]]#Coefficient matrix B\n", - "B = [[-1200],[-600],[-600],[-600],[0],[0],[-1400],[-800]]\n", - "\n", - "\n", - "#Therefore the temperature matrix is\n", - "T = numpy.linalg.inv(A)*B;\n", - "#Temperature at nodal points in degree K\n", - "print\"Temperatures at nodal points in degree K\"\n", - "print\"T1 in degree K\"\n", - "T1 = T[0]\n", - "print T1\n", - "print\"T2 in degree K\"\n", - "T2 = T[1]\n", - "print T2\n", - "print\"T3 in degree K\"\n", - "T3 = T[2]\n", - "print T3\n", - "print\"T4 in degree K\"\n", - "T4 = T[3]\n", - "print T4\n", - "print\"T5 in degree K\"\n", - "T5 = T[4]\n", - "print T5\n", - "print\"T6 in degree K\"\n", - "T6 = T[5]\n", - "print T6\n", - "print\"T7 in degree K\"\n", - "T7 = T[6]\n", - "print T7\n", - "print\"T8 in degree K\"\n", - "T8 = T[7]\n", - "print T8\n" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex3.5:pg-98" - ] - }, - { - "cell_type": "code", - "execution_count": 33, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 3, Example 5\n", - "Temperatures at nodal points in degree C\n", - "T2 in degree C\n", - "[ 1.83976243e-36 4.79441040e-01 3.66134997e-01 3.07581515e-01\n", - " 5.38080937e-01]\n", - "T3 in degree C\n", - "[ 1.46972670e-67 1.92742646e+00 1.47191880e+00 1.23652483e+00\n", - " 1.07886949e+00]\n", - "T4 in degree C\n", - "[ 4.52446173e-92 1.47191880e+00 3.54032873e+00 2.97414801e+00\n", - " 1.67320356e+00]\n", - "T5 in degree C\n", - "[ 6.50142301e-108 1.23652483e+000 2.97414801e+000 5.91733919e+000\n", - " 2.36010173e+000]\n", - "T6 in degree C\n", - "[ 2.06473580e-113 1.16395938e+000 2.79961015e+000 5.57008016e+000\n", - " 3.18199172e+000]\n" - ] - } - ], - "source": [ - " \n", - "import math\n", - "import numpy\n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 3, Example 5\"\n", - "#Thermal conductivity of aluminium in W/(m*K)\n", - "k = 200.0\n", - "#Diameter in m\n", - "d = 20*(10**(-3));\n", - "#Length of fin in m\n", - "L = 0.2;\n", - "#Wall temperature in degree C\n", - "Tw = 400.0;\n", - "#Air temperature in degree C\n", - "Tinfinity = 30;\n", - "#Heat transfer coefficient in W/(m**2*K)\n", - "h = 40.0;\n", - "#internodal distance in x direction in m\n", - "deltax = L/5;\n", - "#Node 1 temperature is equal to wall temperature in degree C\n", - "T1 = Tw;\n", - "#using Nodal Equations, we have Coefficeint Matrix A as\n", - "A = [[2.064,-1,0,0,0],[-1,2.064,-1,0,0],[0,-1,2.064,-1,0],[0,0,-1,2.064,-1],[0,0,0,-1,1.032]]\n", - "#Coefficient matrix B\n", - "B = [401.92,1.92,1.92,1.92,0.96]\n", - "#T2, T3, T4, T5, T6 are nodal temperature in degree C\n", - "#T is the temperature matrix and is transpose of [T2 T3 T4 T5 T6]\n", - "#Therefore the temperature matrix is\n", - "T = numpy.linalg.inv(A)**B;\n", - "#Temperature at nodal points in degree C\n", - "print\"Temperatures at nodal points in degree C\"\n", - "print\"T2 in degree C\"\n", - "T2 = T[0]\n", - "print T2\n", - "print\"T3 in degree C\"\n", - "T3 = T[1]\n", - "print T3\n", - "print\"T4 in degree C\"\n", - "T4 = T[2]\n", - "print T4\n", - "print\"T5 in degree C\"\n", - "T5 = T[3]\n", - "print T5\n", - "print\"T6 in degree C\"\n", - "T6 = T[4]\n", - "print T6\n" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex3.6:pg-104" - ] - }, - { - "cell_type": "code", - "execution_count": 40, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 3, Example 6\n", - "Temperatures at nodal points in degree C\n", - "T1 in degree C\n", - "[ -0. -0. -0. 186.04651163 1.86046512\n", - " 2.79069767 1.86046512 0.46511628 74.41860465]\n", - "T2 in degree C\n", - "[ -0. -0. -0. 74.41860465 1.69263965\n", - " 3.56988732 2.51738192 0.62934548 157.39630784]\n", - "T3 in degree C\n", - "[ -0. -0. -0. 83.72093023 3.88875569\n", - " 4.80220571 3.06401343 0.76600336 65.85950611]\n", - "T4 in degree C\n", - "[ -0. -0. -0. 55.81395349 2.45504675\n", - " 5.7444258 4.10453129 1.02613282 77.58331335]\n", - "T5 in degree C\n", - "[ -0. -0. -0. 37.20930233 1.77415488\n", - " 4.6199952 7.34116519 1.8352913 51.37856629]\n", - "T6 in degree C\n", - "[ -0. -0. -0. 37.20930233 8.78446416\n", - " 4.92927356 2.18652601 0.5466315 33.8527931 ]\n", - "T7 in degree C\n", - "[ -0. -0. -0. 27.90697674 2.46463678\n", - " 9.98561496 3.49556461 0.87389115 35.69887317]\n", - "T8 in degree C\n", - "[ -0. -0. -0. 18.60465116 1.09326301\n", - " 3.49556461 10.57779909 2.64444977 25.17381923]\n", - "T9 in degree C\n", - "[ -0. -0. -0. 9.30232558 0.5466315\n", - " 1.74778231 5.28889954 11.32222489 12.58690961]\n" - ] - } - ], - "source": [ - " \n", - "import math\n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 3, Example 6\"\n", - "#Thermal conductivity of concrete in W/mK\n", - "k = 2;\n", - "#Length in m\n", - "L = 0.2;\n", - "#Breadth in m\n", - "b = 0.2;\n", - "#Depth in m\n", - "d = 0.2;\n", - "#Temperature of hot gas in chimney in degree C\n", - "Tg = 400;\n", - "#Air temperature in degree C\n", - "Tinfinity = 20;\n", - "#internodal distance in x direction in m\n", - "deltax = 0.1;\n", - "#internodal distance in y direction in m\n", - "deltay = 0.1;\n", - "#Heat transfer coefficient in W/(m**2*K)\n", - "h = 20;\n", - "#T1, T2, T3, T4, T5, T6, T7, T8, T9 are nodal temperatures in degree K.\n", - "#T is the temperature matrix and is transpose of [T1 T2 T3 T4 T5 T6 T7 T8 T9]\n", - "#using Nodal Equations, we have Coefficeint Matrix A as\n", - "A = numpy.array([[1,0,-4,2,0,1,0,0,0],[0,1,1,-4,1,0,1,0,0],[0,0,0,2,-4,0,0,2,0],[-3,1,1,0,0,0,0,0,0],[0,0,1,0,0,-3,1,0,0],[0,0,0,2,0,1,-6,1,0],[0,0,0,0,2,0,1,-6,1],[0,0,0,0,0,0,0,1,-2],[1,-4,0,2,0,0,0,0,0]]);\n", - "#Coefficient matrix B\n", - "B = numpy.array([0,0,0,-400,-20,-40,-40,-20,-400]);\n", - "#Therefore the temperature matrix is\n", - "T = numpy.linalg.inv(A)*B;\n", - "#Temperature at nodal points in degree C\n", - "print\"Temperatures at nodal points in degree C\"\n", - "print\"T1 in degree C\"\n", - "T1 = T[0]\n", - "print T1\n", - "print\"T2 in degree C\"\n", - "T2 = T[1]\n", - "print T2\n", - "print\"T3 in degree C\"\n", - "T3 = T[2]\n", - "print T3\n", - "print\"T4 in degree C\"\n", - "T4 = T[3]\n", - "print T4\n", - "print\"T5 in degree C\"\n", - "T5 = T[4]\n", - "print T5\n", - "print\"T6 in degree C\"\n", - "T6 = T[5]\n", - "print T6\n", - "print\"T7 in degree C\"\n", - "T7 = T[6]\n", - "print T7\n", - "print\"T8 in degree C\"\n", - "T8 = T[7]\n", - "print T8\n", - "print\"T9 in degree C\"\n", - "T9 = T[8]\n", - "print T9\n" - ] - } - ], - "metadata": { - "kernelspec": { - "display_name": "Python 2", - "language": "python", - "name": "python2" - }, - "language_info": { - "codemirror_mode": { - "name": "ipython", - "version": 2 - }, - "file_extension": ".py", - "mimetype": "text/x-python", - "name": "python", - "nbconvert_exporter": "python", - "pygments_lexer": "ipython2", - "version": "2.7.11" - } - }, - "nbformat": 4, - "nbformat_minor": 0 -} diff --git a/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter4.ipynb b/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter4.ipynb index 6c85f1a7..54a5875b 100644 --- a/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter4.ipynb +++ b/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter4.ipynb @@ -35,6 +35,10 @@ } ], "source": [ + " \n", + "\n", + " \n", + " \n", "import math\n", " \n", "print\"Introduction to heat transfer by S.K.Som, Chapter 4, Example 1\"\n", @@ -55,7 +59,8 @@ "if Bi<0.1:\n", " print\"Problem is suitable for lumped parameter analysis\"\n", "else:\n", - " print\"Problem is not suitable for lumped parameter analysis\"" + " print\"Problem is not suitable for lumped parameter analysis\"\n", + "\n" ] }, { @@ -67,7 +72,7 @@ }, { "cell_type": "code", - "execution_count": 3, + "execution_count": 1, "metadata": { "collapsed": false }, @@ -85,6 +90,7 @@ } ], "source": [ + " \n", "import math\n", " \n", "print\"Introduction to heat transfer by S.K.Som, Chapter 4, Example 2\"\n", @@ -109,7 +115,7 @@ "#Required time in sec\n", "t = (-8)*math.log(0.01);\n", "print\"Time required in seconds\"\n", - "print\"t=\",t" + "print\"t=\",t\n" ] }, { @@ -121,7 +127,7 @@ }, { "cell_type": "code", - "execution_count": 4, + "execution_count": 2, "metadata": { "collapsed": false }, @@ -137,6 +143,7 @@ } ], "source": [ + " \n", "import math\n", " \n", "print\"Introduction to heat transfer by S.K.Som, Chapter 4, Example 3\"\n", @@ -150,7 +157,7 @@ "#Maximum dimension in metre\n", "a = ((6*k)*Bi)/h;\n", "print\"Maximum dimension in metre for lumped parameter analysis\"\n", - "print\"a=\",a" + "print\"a=\",a\n" ] }, { @@ -179,6 +186,7 @@ } ], "source": [ + " \n", "from scipy.integrate import quad\n", "import math\n", "print\"Introduction to heat transfer by S.K.Som, Chapter 4, Example 4\"\n", @@ -214,7 +222,7 @@ "E = (((h*math.pi)*d)*H)*quad(lambda t:(80.0-25.0)*math.e*(-t/472.5),0,60.0*t)[0];\n", "print\"Energy required for cooling in KJ\"\n", "E = E/1000.0\n", - "print \"E=\",E" + "print \"E=\",E\n" ] }, { @@ -226,7 +234,7 @@ }, { "cell_type": "code", - "execution_count": 6, + "execution_count": 3, "metadata": { "collapsed": false }, @@ -244,6 +252,7 @@ } ], "source": [ + " \n", "import math\n", " \n", "print\"Introduction to heat transfer by S.K.Som, Chapter 4, Example 5\"\n", @@ -279,7 +288,7 @@ "Q = ((((0.69*k)*2)*L)*(Tinfinity-Ti))/alpha;\n", "print\"Heat transfer rate in MJ\"\n", "Q = Q/(10**6)\n", - "print\"Q=\",Q" + "print\"Q=\",Q\n" ] }, { @@ -291,7 +300,7 @@ }, { "cell_type": "code", - "execution_count": 7, + "execution_count": 4, "metadata": { "collapsed": false }, @@ -309,6 +318,7 @@ } ], "source": [ + " \n", "import math\n", " \n", "print\"Introduction to heat transfer by S.K.Som, Chapter 4, Example 6\"\n", @@ -346,7 +356,7 @@ "Q = (((0.4*k)*L)*(Ti-Tinfinity))/alpha;\n", "print\"Heat transfer rate in MJ\"\n", "Q = Q/(10**6)\n", - "print\"Q=\",Q" + "print\"Q=\",Q\n" ] }, { @@ -358,7 +368,7 @@ }, { "cell_type": "code", - "execution_count": 8, + "execution_count": 5, "metadata": { "collapsed": false }, @@ -376,6 +386,7 @@ } ], "source": [ + " \n", "import math\n", " \n", "print\"Introduction to heat transfer by S.K.Som, Chapter 4, Example 7\"\n", @@ -413,7 +424,7 @@ "Q = (((((0.4*k)*math.pi)*ro)*ro)*(Ti-Tinfinity))/alpha;\n", "print\"Heat transfer rate per unit length in MJ/m\"\n", "Q = Q/(10**6)\n", - "print\"Q=\",Q" + "print\"Q=\",Q\n" ] }, { @@ -425,7 +436,7 @@ }, { "cell_type": "code", - "execution_count": 9, + "execution_count": 6, "metadata": { "collapsed": false }, @@ -441,6 +452,7 @@ } ], "source": [ + " \n", "import math\n", "\n", "print\"Introduction to heat transfer by S.K.Som, Chapter 4, Example 8\"\n", @@ -469,7 +481,7 @@ "t = ((Fo*ro)*ro)/alpha;\n", "print\"Time required in minutes\"\n", "t = t/60\n", - "print\"t=\",t" + "print\"t=\",t\n" ] }, { @@ -481,7 +493,7 @@ }, { "cell_type": "code", - "execution_count": 10, + "execution_count": 7, "metadata": { "collapsed": false }, @@ -497,6 +509,7 @@ } ], "source": [ + " \n", "import math\n", " \n", "print\"Introduction to heat transfer by S.K.Som, Chapter 4, Example 9\"\n", @@ -539,7 +552,7 @@ "#Temperature in °C\n", "T = Tinfinity+z*(Ti-Tinfinity);\n", "print\"Tempearture of bar in °C\"\n", - "print\"T=\",T" + "print\"T=\",T\n" ] }, { @@ -551,7 +564,7 @@ }, { "cell_type": "code", - "execution_count": 13, + "execution_count": 8, "metadata": { "collapsed": false }, @@ -576,6 +589,7 @@ } ], "source": [ + " \n", "import math\n", " \n", "print\"Introduction to heat transfer by S.K.Som, Chapter 4, Example 10\"\n", @@ -645,7 +659,17 @@ "#Therefore ((To-Tinf)/(Ti-Tinf))plate1*((To-Tinf)/(Ti-Tinf))plate2=A*B\n", "T=A*B\n", "print\"The calculated value is very close to the required value of 0.6.Hence the time required for the centre of the beam to reach 310°C is nearly 1200s or 20 minutes.\" \n", - "print\"T=\",T" + "print\"T=\",T\n", + " \n", + " \n", + " \n", + " \n", + " \n", + " \n", + " \n", + " \n", + " \n", + " \n" ] }, { @@ -657,7 +681,7 @@ }, { "cell_type": "code", - "execution_count": 14, + "execution_count": 9, "metadata": { "collapsed": false }, @@ -673,6 +697,7 @@ } ], "source": [ + " \n", "import math\n", " \n", "print\"Introduction to heat transfer by S.K.Som, Chapter 4, Example 11\"\n", @@ -694,7 +719,22 @@ "#Therefore 10/t**0.5=0.38...this implies t=(10/0.38)**2\n", "print\"The time required for the temprature to reach 255°C at a depth of 80mm, in minutes is\"\n", "t=(10/0.38)**2/60\n", - "print\"T=\",T" + "print\"T=\",T\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n" ] }, { @@ -724,6 +764,7 @@ } ], "source": [ + " \n", "import math\n", "import scipy \n", "print\"Introduction to heat transfer by S.K.Som, Chapter 4, Example 12\"\n", @@ -747,7 +788,18 @@ "print\"The temprature at a depth(x) of 100mm after a time(t) of 100 seconds,in °C is\"\n", "T=Ti+((2*qo*(alpha*t/math.pi)**0.5)/(k))*math.e**((-x**2.0)/(4*alpha*t))-((qo*x)/(k))*scipy.special.erf(x/(2*(alpha*t)**0.5))\n", "print\"T=\",T\n", - "#NOTE:The answer in the book is incorrect(Calculation mistake)" + "#NOTE:The answer in the book is incorrect(Calculation mistake)\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n" ] }, { @@ -759,7 +811,7 @@ }, { "cell_type": "code", - "execution_count": 2, + "execution_count": 17, "metadata": { "collapsed": false }, @@ -770,7 +822,7 @@ "text": [ "Introduction to heat transfer by S.K.Som, Chapter 4, Example 14\n", "Temperature distribution after 25 mins in °C\n", - "T= [[ 2.29192547e+02 2.91925466e+00 1.11801242e+00 4.34782609e-01\n", + "[[ 2.29192547e+02 2.91925466e+00 1.11801242e+00 4.34782609e-01\n", " 1.86335404e-01 6.21118012e-02]\n", " [ 8.75776398e+01 8.75776398e+00 3.35403727e+00 1.30434783e+00\n", " 5.59006211e-01 1.86335404e-01]\n", @@ -786,6 +838,7 @@ } ], "source": [ + " \n", "import math\n", "import numpy\n", " \n", @@ -811,8 +864,10 @@ "#From Eq. 4.126\n", "#Temperature distribution after one time step\n", "T = numpy.linalg.inv(A)*B;\n", + "\n", + " \n", "print\"Temperature distribution after 25 mins in °C\"\n", - "print\"T=\",T" + "print T\n" ] } ], diff --git a/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter4_fMX8RWT.ipynb b/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter4_fMX8RWT.ipynb deleted file mode 100644 index 54a5875b..00000000 --- a/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter4_fMX8RWT.ipynb +++ /dev/null @@ -1,895 +0,0 @@ -{ - "cells": [ - { - "cell_type": "markdown", - "metadata": { - "collapsed": true - }, - "source": [ - "# Chapter 04:Unsteady conduction" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex4.1:pg-137" - ] - }, - { - "cell_type": "code", - "execution_count": 1, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 4, Example 1\n", - "Biot number is\n", - "Bi= 0.277777777778\n", - "Problem is not suitable for lumped parameter analysis\n" - ] - } - ], - "source": [ - " \n", - "\n", - " \n", - " \n", - "import math\n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 4, Example 1\"\n", - "#Diameter of apple in m\n", - "d = 100*(10**(-3));\n", - "#radius in m\n", - "r = d/2;\n", - "#Thermal conductivity of apple in W/(m*K)\n", - "k = 0.6;\n", - "#Heat transfer coefficient in W/(m**2*°C)\n", - "h = 10;\n", - "#Caculating characteristic dimension in m\n", - "Lc = (((((4*math.pi)*r)*r)*r)/3)/(((4*math.pi)*r)*r);\n", - "#Biot number\n", - "print\"Biot number is\"\n", - "Bi = (h*Lc)/k\n", - "print\"Bi=\",Bi\n", - "if Bi<0.1:\n", - " print\"Problem is suitable for lumped parameter analysis\"\n", - "else:\n", - " print\"Problem is not suitable for lumped parameter analysis\"\n", - "\n" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex4.2:pg-138 " - ] - }, - { - "cell_type": "code", - "execution_count": 1, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 4, Example 2\n", - "Time constant in seconds is\n", - "tc= 8.0\n", - "Time required in seconds\n", - "t= 36.8413614879\n" - ] - } - ], - "source": [ - " \n", - "import math\n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 4, Example 2\"\n", - "#Diameter of sphere in m\n", - "d = 1.5*(10**(-3));\n", - "#radius in m\n", - "r = d/2;\n", - "#Thermal conductivity of sphere in W/(m*°C)\n", - "k = 40.0;\n", - "#Density in kg/m**3\n", - "rho = 8000.0;\n", - "#Specific heat in J/(Kg*K)\n", - "c = 300.0;\n", - "#Heat transfer coefficient in W/(m**2*°C)\n", - "h = 75.0;\n", - "#Time constant in sec\n", - "tc = ((rho*c)*(((((4*math.pi)*r)*r)*r)/3))/((((h*4)*math.pi)*r)*r);\n", - "print\"Time constant in seconds is\"\n", - "print\"tc=\",tc\n", - "#Using eq. 4.4\n", - "#Given fraction is 0.01 (1 percent)\n", - "#Required time in sec\n", - "t = (-8)*math.log(0.01);\n", - "print\"Time required in seconds\"\n", - "print\"t=\",t\n" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex4.3:pg-138" - ] - }, - { - "cell_type": "code", - "execution_count": 2, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 4, Example 3\n", - "Maximum dimension in metre for lumped parameter analysis\n", - "a= 5.0\n" - ] - } - ], - "source": [ - " \n", - "import math\n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 4, Example 3\"\n", - "#Heat transfer coefficient in W/(m**2*K)\n", - "h = 30;\n", - "#Thermal conductivity of sphere in W/(m*K)\n", - "k = 250;\n", - "#Biot number for lumped parameter analysis is 0.1\n", - "Bi = 0.1;\n", - "#Characteristic dimension of a cube is (a/6) where a is the side of cube in metre\n", - "#Maximum dimension in metre\n", - "a = ((6*k)*Bi)/h;\n", - "print\"Maximum dimension in metre for lumped parameter analysis\"\n", - "print\"a=\",a\n" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex4.4:pg-146" - ] - }, - { - "cell_type": "code", - "execution_count": 5, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 4, Example 4\n", - "Time required to cool milk in minutes\n", - "Energy required for cooling in KJ\n", - "E= -319.013666564\n" - ] - } - ], - "source": [ - " \n", - "from scipy.integrate import quad\n", - "import math\n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 4, Example 4\"\n", - "#Diameter of glass in m\n", - "d = 50*(10**(-3));\n", - "#radius in m\n", - "r = d/2;\n", - "#Height of milk in glass in m\n", - "H = 0.1;\n", - "#Initial temperature of milk in °C\n", - "T = 80.0;\n", - "#Cold water temperature in °C\n", - "Tf = 25.0;\n", - "#Heat transfer coefficient in W/(m**2*°C)\n", - "h = 100.0;\n", - "#Thermal conductivity of milk in W/(m*K)\n", - "k = 0.6;\n", - "#Density of milk in kg/m**3\n", - "rho = 900.0;\n", - "#Specific heat in J/(Kg*K)\n", - "c = 4.2*(10**3);\n", - "#Since the milk temperature is always maintained as constant.\n", - "#Therefore it can be assumed as lumped paramteter analysis.\n", - "#Time constant n seconds\n", - "tcs = (((((rho*c)*math.pi)*r)*r)*H)/(((h*math.pi)*d)*H);\n", - "#Time constant in minutes\n", - "tc = tcs/60;\n", - "#Calculating from eq. 4.3 time taken to cool milk from 80°C to 30°C\n", - "t = -tc*math.log((30.0-Tf)/(T-Tf));\n", - "print\"Time required to cool milk in minutes\"\n", - "t\n", - "#Energy transferred during cooling\n", - "E = (((h*math.pi)*d)*H)*quad(lambda t:(80.0-25.0)*math.e*(-t/472.5),0,60.0*t)[0];\n", - "print\"Energy required for cooling in KJ\"\n", - "E = E/1000.0\n", - "print \"E=\",E\n" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex4.5:pg-159" - ] - }, - { - "cell_type": "code", - "execution_count": 3, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 4, Example 5\n", - "Time required in hours\n", - "t= 7.5\n", - "Heat transfer rate in MJ\n", - "Q= 186.3\n" - ] - } - ], - "source": [ - " \n", - "import math\n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 4, Example 5\"\n", - "#Thermal conductivity of wall in W/(m*K)\n", - "k = 0.6;\n", - "#Thermal diffusivity in m**2/s\n", - "alpha = 5*(10**(-7));\n", - "#Thickness in m\n", - "L = 0.15;\n", - "#Initial temperature in °C\n", - "Ti = 30;\n", - "#Temperature of hot gas in °C\n", - "Tinfinity = 780;\n", - "#Heat transfer coefficient in W/(m**2*K)\n", - "h = 20;\n", - "#Surface temperaute to be achieved in °C\n", - "To = 480;\n", - "#Dimensionless temperature ratio\n", - "z = (To-Tinfinity)/(Ti-Tinfinity);\n", - "#Biot number\n", - "Bi = (h*L)/k;\n", - "#For this value of (1/Bi) and dimensionless temp. ratio\n", - "#From Fig. 4.11 Fourier number is\n", - "Fo = 0.6;\n", - "#Time required in seconds\n", - "t = ((Fo*L)*L)/alpha;\n", - "print\"Time required in hours\"\n", - "t = t/3600\n", - "print\"t=\",t\n", - "#From fig. 4.13, for this Bi and Fo*Bi*Bi, we have ratio of heats as\n", - "#Q/Qi=0.69\n", - "#Heat transfer in J\n", - "Q = ((((0.69*k)*2)*L)*(Tinfinity-Ti))/alpha;\n", - "print\"Heat transfer rate in MJ\"\n", - "Q = Q/(10**6)\n", - "print\"Q=\",Q\n" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex4.6:pg-166" - ] - }, - { - "cell_type": "code", - "execution_count": 4, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 4, Example 6\n", - "Temperature at this distance in °C\n", - "T= 355.5\n", - "Heat transfer rate in MJ\n", - "Q= 100.0\n" - ] - } - ], - "source": [ - " \n", - "import math\n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 4, Example 6\"\n", - "#Thickness of plate in m\n", - "L = 0.2;\n", - "#Initial temperature in °C\n", - "Ti = 530;\n", - "#Heat transfer coefficient in W/(m**2*K)\n", - "h = 500;\n", - "#Given distance in m\n", - "x = L-20*(10**(-3));\n", - "#Temperature of surrounding in °C\n", - "Tinfinity = 30;\n", - "#Given time in seconds\n", - "t = 225;\n", - "#Thermal conductivity of aluminium in W/(m*K)\n", - "k = 200;\n", - "#Thermal diffusivity in m**2/s\n", - "alpha = 8*(10**(-5));\n", - "#Biot number\n", - "Bi = (h*L)/k;\n", - "#Fourier number\n", - "Fo = (alpha*t)/(L*L);\n", - "#From fig. 4.11, at this Fo and (1/Bi), we have dimensionless temperature\n", - "#ratio to be 0.7\n", - "#From fig. 4.12 for this (1/Bi) and (x/L), we have another dimensionless\n", - "#temperature to be 0.93\n", - "#Temperature in °C\n", - "T = Tinfinity+(0.93*0.7)*(Ti-Tinfinity);\n", - "print\"Temperature at this distance in °C\"\n", - "print\"T=\",T\n", - "#From fig. 4.13, for this Bi and Fo*Bi*Bi, we have ratio of heats as\n", - "#Q/Qi=0.4\n", - "#Heat transfer in J\n", - "Q = (((0.4*k)*L)*(Ti-Tinfinity))/alpha;\n", - "print\"Heat transfer rate in MJ\"\n", - "Q = Q/(10**6)\n", - "print\"Q=\",Q\n" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex4.7:pg-171" - ] - }, - { - "cell_type": "code", - "execution_count": 5, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 4, Example 7\n", - "Temperature at this radius in °C\n", - "T= 300.0\n", - "Heat transfer rate per unit length in MJ/m\n", - "Q= 33.2639222145\n" - ] - } - ], - "source": [ - " \n", - "import math\n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 4, Example 7\"\n", - "#Radius in m\n", - "ro = 0.15;\n", - "#Initial temperature in °C\n", - "Ti = 530;\n", - "#Temperature of surrounding in °C\n", - "Tinfinity = 30;\n", - "#Heat transfer coefficient in W/(m**2*K)\n", - "h = 380;\n", - "#Thermal conductivity of aluminium in W/(m*K)\n", - "k = 200;\n", - "#Thermal diffusivity in m**2/s\n", - "alpha = 8.5*(10**(-5));\n", - "#Given radius at which temperature has to be find out in m\n", - "r = 0.12;\n", - "#Given time in seconds\n", - "t = 265;\n", - "#Fourier number\n", - "Fo = (alpha*t)/(ro**2);\n", - "#Biot number\n", - "Bi = (h*ro)/k;\n", - "#From fig. 4.15, at this fourier number,Fo and (1/Bi), we have dimensionless temperature\n", - "#ratio to be 0.6\n", - "#From fig. 4.16 for this (1/Bi) and (r/ro), we have another dimensionless\n", - "#temperature to be 0.9\n", - "#Temperature in °C\n", - "T = Tinfinity+(0.9*0.6)*(Ti-Tinfinity);\n", - "print\"Temperature at this radius in °C\"\n", - "print\"T=\",T\n", - "#From fig. 4.17, for this Bi and Fo*Bi*Bi, we have ratio of heats as\n", - "#Q/Qi=0.4\n", - "#Heat transfer per metre in J/m\n", - "Q = (((((0.4*k)*math.pi)*ro)*ro)*(Ti-Tinfinity))/alpha;\n", - "print\"Heat transfer rate per unit length in MJ/m\"\n", - "Q = Q/(10**6)\n", - "print\"Q=\",Q\n" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex4.8:pg-174" - ] - }, - { - "cell_type": "code", - "execution_count": 6, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 4, Example 8\n", - "Time required in minutes\n", - "t= 4.16666666667\n" - ] - } - ], - "source": [ - " \n", - "import math\n", - "\n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 4, Example 8\"\n", - "#Radius in m\n", - "ro = 0.05;\n", - "#Initial temperature in °C\n", - "Ti = 530;\n", - "#Temperature of surrounding in °C\n", - "Tinfinity = 30;\n", - "#Heat transfer coefficient in W/(m**2*K)\n", - "h = 500;\n", - "#Thermal conductivity of aluminium in W/(m*K)\n", - "k = 50;\n", - "#Thermal diffusivity in m**2/s\n", - "alpha = 1.5*(10**(-5));\n", - "#Required centre temperature to achieve in °C\n", - "To = 105;\n", - "#Dimensionless temperature\n", - "z = (To-Tinfinity)/(Ti-Tinfinity);\n", - "#Biot number\n", - "Bi = (h*ro)/k;\n", - "#For this value of (1/Bi) and dimensionless temp. ratio\n", - "#From Fig. 4.19 Fourier number is\n", - "Fo = 1.5;\n", - "#Time required in seconds\n", - "t = ((Fo*ro)*ro)/alpha;\n", - "print\"Time required in minutes\"\n", - "t = t/60\n", - "print\"t=\",t\n" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex4.9:pg-177" - ] - }, - { - "cell_type": "code", - "execution_count": 7, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 4, Example 9\n", - "Tempearture of bar in °C\n", - "T= 260.3\n" - ] - } - ], - "source": [ - " \n", - "import math\n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 4, Example 9\"\n", - "#Thermal conductivity of aluminium in W/(m*K)\n", - "k = 198;\n", - "#Length in m\n", - "L = 0.18;\n", - "#Breadth in m\n", - "b = 0.104;\n", - "#Initial temperature in °C\n", - "Ti = 730;\n", - "#Temperature of surrounding in °C\n", - "Tinfinity = 30;\n", - "#Heat transfer coefficient in W/(m**2*K)\n", - "h = 1100;\n", - "#Thermal diffusivity in m**2/s\n", - "alpha = 8.1*(10**(-5));\n", - "#Given time in seconds\n", - "t = 100;\n", - "#Bar can be considered to be an intersection of two infinite plates of\n", - "#thickness L1 and L2 in m\n", - "L1 = L/2;\n", - "L2 = b/2;\n", - "#For plate 1\n", - "#Fourier number\n", - "Fo1 = (alpha*t)/(L1**2);\n", - "#Biot number\n", - "Bi1 = (h*L1)/k;\n", - "#From fig. 4.11, at this Fo and (1/Bi), we have dimensionless temperature\n", - "#ratio to be 0.7\n", - "#For plate 2\n", - "#Fourier number\n", - "Fo2 = (alpha*t)/(L2**2);\n", - "#Biot number\n", - "Bi2 = (h*L2)/k;\n", - "#From fig. 4.11, at this Fo and (1/Bi), we have dimensionless temperature\n", - "#ratio to be 0.47\n", - "#Therefore combined dimensionless temperature ratio is multiply of two\n", - "z = 0.47*0.7;\n", - "#Temperature in °C\n", - "T = Tinfinity+z*(Ti-Tinfinity);\n", - "print\"Tempearture of bar in °C\"\n", - "print\"T=\",T\n" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex4.10:pg-180" - ] - }, - { - "cell_type": "code", - "execution_count": 8, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 4, Example 10\n", - "The factor((To-Tinf)/(Ti-Tinf)) is \n", - "For plate 1\n", - "A= 0.85\n", - "For plate 2\n", - "B= 0.8\n", - "For plate 1\n", - "A= 0.83\n", - "For plate 2\n", - "B= 0.72\n", - "The calculated value is very close to the required value of 0.6.Hence the time required for the centre of the beam to reach 310°C is nearly 1200s or 20 minutes.\n", - "T= 0.5976\n" - ] - } - ], - "source": [ - " \n", - "import math\n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 4, Example 10\"\n", - "#An iron beam of rectangular cross section of size length,L=300mm by breadth,B=200 mm is used in the construction of a building\n", - "#Initially the beam is at a uniform temprature(Ti) of 30°C.\n", - "#Due to an accidental fire,the beam is suddenly exposed to hot gases at temprature,Tinf=730°C,with a convective heat transfer coefficient(h) of 100 W/(m**2*K)\n", - "#To determine the time required for the centre plane of the beam to reach a temprature(To) of 310°C.\n", - "To=310;\n", - "Tinf=730;\n", - "Ti=30;\n", - "#Take thermal conductivity k=73W/(m*K) and thermal diffusivity of the beam alpha=2.034*10**-5m**2/s \n", - "alpha=2.034*10**-5; \n", - "k=73; \n", - "h=100; \n", - "#The rectangular iron beam can be considered as an intersection of an infinite plate 1 having thickness 2*L1=300mm and a second infinite plate 2 of thickness 2*L2=200mm \n", - "L1=0.15;#in metre\n", - "L2=0.10;#in metre\n", - "#Here the faactor X=((To-Tinf)/(Ti-Tinf))\n", - "print\"The factor((To-Tinf)/(Ti-Tinf)) is \"\n", - "X=((To-Tinf)/(Ti-Tinf))\n", - "#Therefore we can write 0.6=((To-Tinf)/(Ti-Tinf))plate 1 *((To-Tinf)/(Ti-Tinf))plate2\n", - "#A straight forward solution is not possible.We have to adopt an iterative method of solution \n", - "#At first ,a value of time(t) is assumed to determine the centre-line temprature of the beam.The value of t at which((To-Tinf)/(Ti-Tinf))beam =0.6 is satisfied\n", - "#Let us first assume time, t=900s\n", - "t=900;\n", - "print\"For plate 1\"\n", - "#For plate1 Biot number Bi1=h*L1/k \n", - "Bi1=h*L1/k \n", - "Y=1/Bi1\n", - "#Fourier number(Fo1) is\n", - "Fo1=alpha*t/L1**2\n", - "#At Fo=0.814 and (1/Bi)=4.87...We read from graphs A=((To-Tinf)/(Ti-Tinf))plate1= 0.85\n", - "A=0.85;\n", - "print\"A=\",A\n", - "print\"For plate 2\"\n", - "#For plate1 Biot number Bi2=h*L2/k \n", - "Bi2=h*L2/k \n", - "Y=1/Bi2\n", - "#Fourier number(Fo2) is\n", - "Fo2=alpha*t/L2**2\n", - "#At Fo=1.83 and (1/Bi)=7.3...We read from graphs B=((To-Tinf)/(Ti-Tinf))plate2= 0.8\n", - "B=0.8;\n", - "print\"B=\",B\n", - "#Therefore ((To-Tinf)/(Ti-Tinf))plate1*((To-Tinf)/(Ti-Tinf))plate2=A*B\n", - "T=A*B\n", - "#Since the calculated value of 0.68 is greater than the required value of 0.60 and Tinf>To>Ti,The assume dvalue of t is less.\n", - "#So let us take time,t=1200s for the second iteration\n", - "t=1200;\n", - "print\"For plate 1\"\n", - "#For plate1 Biot number Bi1=h*L1/k \n", - "Bi1=h*L1/k \n", - "Y=1/Bi1\n", - "#Fourier number (Fo1)\n", - "Fo1=alpha*t/L1**2\n", - "#At Fo=1.08 and (1/Bi)=4.87...We read from graphs A=((To-Tinf)/(Ti-Tinf))plate1= 0.83\n", - "A=0.83;\n", - "print\"A=\",A\n", - "print\"For plate 2\"\n", - "#For plate1 Biot number Bi2=h*L2/k \n", - "Bi2=h*L2/k \n", - "Y=1/Bi2\n", - "#Fourier number (Fo2)\n", - "Fo2=alpha*t/L2**2\n", - "#At Fo=2.44 and (1/Bi)=7.3...We read from graphs B=((To-Tinf)/(Ti-Tinf))plate2= 0.72\n", - "B=0.72;\n", - "print\"B=\",B\n", - "#Therefore ((To-Tinf)/(Ti-Tinf))plate1*((To-Tinf)/(Ti-Tinf))plate2=A*B\n", - "T=A*B\n", - "print\"The calculated value is very close to the required value of 0.6.Hence the time required for the centre of the beam to reach 310°C is nearly 1200s or 20 minutes.\" \n", - "print\"T=\",T\n", - " \n", - " \n", - " \n", - " \n", - " \n", - " \n", - " \n", - " \n", - " \n", - " \n" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex4.11:pg-182" - ] - }, - { - "cell_type": "code", - "execution_count": 9, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 4, Example 11\n", - "The time required for the temprature to reach 255°C at a depth of 80mm, in minutes is\n", - "T= 255\n" - ] - } - ], - "source": [ - " \n", - "import math\n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 4, Example 11\"\n", - "#A large slab wrought-iron is at a uniform temprature of Ti=550°C.\n", - "#The temprature of one surface is suddenly changed to Tinf=50°C\n", - "Tinf=50;\n", - "Ti=550; \n", - "#For slab conductivity(k=60W/(m*K)),Thermal diffusivity(alpha=1.6*10**-5m**2/s)\n", - "#To calculate the time(t) required for the temprature to reach T=255°C at a depth of 80mm\n", - "k=60;\n", - "T=255;\n", - "alpha=1.6**10-5;\n", - "#Similarity parameter,eta=x/(2*(alpha*t)**0.5)=(10/t**0.5)\n", - "#((T-Tinf)/(Ti-Tinf))=erf(10/t**0.5)...where erf is the error function.\n", - "#Let ((T-Tinf)/(Ti-Tinf))=X\n", - "X=((T-Tinf)/(Ti-Tinf));\n", - "#This implies erf(10/t**0.5)=0.41\n", - "#We read from the table the value of eta(=10/t**0.5)=0.38....corresponding to erf(eta)=0.41\n", - "#Therefore 10/t**0.5=0.38...this implies t=(10/0.38)**2\n", - "print\"The time required for the temprature to reach 255°C at a depth of 80mm, in minutes is\"\n", - "t=(10/0.38)**2/60\n", - "print\"T=\",T\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex4.12:pg-186" - ] - }, - { - "cell_type": "code", - "execution_count": 15, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 4, Example 12\n", - "gaussian error function is \n", - "E= 0.998109069322\n", - "The temprature at a depth(x) of 100mm after a time(t) of 100 seconds,in °C is\n", - "T= -29851.5095103\n" - ] - } - ], - "source": [ - " \n", - "import math\n", - "import scipy \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 4, Example 12\"\n", - "#A large block of nickel steel conductivity(k=20W/(m*K)),thermal diffusivity(alpha=0.518*10-5 m**2/s) is at uniform temprature(Ti) of 30°C.\n", - "Ti=30.0;\n", - "k=20.0;\n", - "alpha=0.518*10.0**-5.0;\n", - "#One surface of the block is suddenly exposed to a constant surface heat flux(qo) of 6MW/m**2.\n", - "qo=6*10**6;#in W/m**2\n", - "#To determine the temprature at a depth(x) of 100mm after a time(t) of 100 seconds.\n", - "t=100.0;\n", - "x=0.1;#in metre\n", - "#Similarity parameter,eta=x/(4*alpha*t)\n", - "eta=x/((4.0*alpha*t)**0.5)\n", - "#E is gaussian error function\n", - "print\"gaussian error function is \"\n", - "E=scipy.special.erf(eta)\n", - "print\"E=\",E\n", - "#The equation to determine temprature is T-Ti=((2*qo(alpha*t/math.pi)**0.5)/(k))*e**((-x**2)/(4*alpha*t))-((qo*x)/(k))*erf(x/(2.0*(alpha*t)**0.5))\n", - "#Above equation can also be written as T=Ti+((2*qo(alpha*t/math.pi)**0.5)/(k))*e**((-x**2)/(4*alpha*t))-((qo*x)/(k))*erf(x/(2.0*(alpha*t)**0.5))\n", - "print\"The temprature at a depth(x) of 100mm after a time(t) of 100 seconds,in °C is\"\n", - "T=Ti+((2*qo*(alpha*t/math.pi)**0.5)/(k))*math.e**((-x**2.0)/(4*alpha*t))-((qo*x)/(k))*scipy.special.erf(x/(2*(alpha*t)**0.5))\n", - "print\"T=\",T\n", - "#NOTE:The answer in the book is incorrect(Calculation mistake)\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex4.14:pg-187 " - ] - }, - { - "cell_type": "code", - "execution_count": 17, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 4, Example 14\n", - "Temperature distribution after 25 mins in °C\n", - "[[ 2.29192547e+02 2.91925466e+00 1.11801242e+00 4.34782609e-01\n", - " 1.86335404e-01 6.21118012e-02]\n", - " [ 8.75776398e+01 8.75776398e+00 3.35403727e+00 1.30434783e+00\n", - " 5.59006211e-01 1.86335404e-01]\n", - " [ 3.35403727e+01 3.35403727e+00 8.94409938e+00 3.47826087e+00\n", - " 1.49068323e+00 4.96894410e-01]\n", - " [ 1.30434783e+01 1.30434783e+00 3.47826087e+00 9.13043478e+00\n", - " 3.91304348e+00 1.30434783e+00]\n", - " [ 5.59006211e+00 5.59006211e-01 1.49068323e+00 3.91304348e+00\n", - " 1.02484472e+01 3.41614907e+00]\n", - " [ 3.72670807e+00 3.72670807e-01 9.93788820e-01 2.60869565e+00\n", - " 6.83229814e+00 8.94409938e+00]]\n" - ] - } - ], - "source": [ - " \n", - "import math\n", - "import numpy\n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 4, Example 14\"\n", - "#Nodal distance Deltax in m\n", - "deltax = 0.1;\n", - "#Time in seconds\n", - "t = 25*60;\n", - "#timestep deltaT in seconds\n", - "deltaT = 500;\n", - "#Number of increment\n", - "n = t/deltaT;\n", - "#Temperature raised in °C\n", - "To = 580.0;\n", - "#Using Eq. 4.114 for interior grid points, table 4.8 for exterior node\n", - "#Using Eq. 4.125a to 4.125f are written in matrix form\n", - "#Coefficient matrix A is\n", - "A = [[-3,1,0,0,0,0],[1,-3,1,0,0,0],[0,1,-3,1,0,0],[0,0,1,-3,1,0],[0,0,0,1,-3,1],[0,0,0,0,2,-3]]\n", - "#Coefficient matrix B is\n", - "B = [-600,-20,-20,-20,-20,-20];\n", - "#Temperature matrix is transpose of [T2 T3 T4 T5 T6 T7] where\n", - "#T2 to T7 are temperature in °C\n", - "#From Eq. 4.126\n", - "#Temperature distribution after one time step\n", - "T = numpy.linalg.inv(A)*B;\n", - "\n", - " \n", - "print\"Temperature distribution after 25 mins in °C\"\n", - "print T\n" - ] - } - ], - "metadata": { - "kernelspec": { - "display_name": "Python 2", - "language": "python", - "name": "python2" - }, - "language_info": { - "codemirror_mode": { - "name": "ipython", - "version": 2 - }, - "file_extension": ".py", - "mimetype": "text/x-python", - "name": "python", - "nbconvert_exporter": "python", - "pygments_lexer": "ipython2", - "version": "2.7.11" - } - }, - "nbformat": 4, - "nbformat_minor": 0 -} diff --git a/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter5.ipynb b/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter5.ipynb index 5b3d46e7..1751c7ce 100644 --- a/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter5.ipynb +++ b/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter5.ipynb @@ -38,6 +38,7 @@ } ], "source": [ + " \n", "import math \n", "from scipy.integrate import quad\n", " \n", @@ -73,7 +74,23 @@ "#Q is the rate of heat transfer\n", "print\"The rate of heat transfer in W/m of width is\"\n", "Q=hbarL*L*(T2-T1)\n", - "print\"Q=\",Q" + "print\"Q=\",Q\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n" ] }, { @@ -85,7 +102,7 @@ }, { "cell_type": "code", - "execution_count": 27, + "execution_count": 2, "metadata": { "collapsed": false }, @@ -102,6 +119,7 @@ } ], "source": [ + " \n", "import math\n", " \n", "print\"Introduction to heat transfer by S.K.Som, Chapter 5, Example 4\"\n", @@ -126,7 +144,18 @@ "#from an enrgy balance we can write as E=27.063*U**0.85*L*B*(Ts-Tinf)\n", "print\"The minimum flow velocity in m/s is\"\n", "U=(E/(27.063*L*B*(Ts-Tinf)))**(1/0.85)\n", - "print\"U=\",U" + "print\"U=\",U\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n" ] }, { @@ -138,7 +167,7 @@ }, { "cell_type": "code", - "execution_count": 1, + "execution_count": 3, "metadata": { "collapsed": false }, @@ -161,8 +190,10 @@ } ], "source": [ + " \n", "import math\n", " \n", + " \n", "print\"Introduction to heat transfer by S.K.Som, Chapter 5, Example 6\"\n", "#Air at 1atm pressure and temprature(Tin)=30°C enters a tube of 25mm diameter(D) with a velocity(U) of 10m/s\n", "D=0.025;#in metre\n", @@ -200,7 +231,25 @@ "k=0.0285;\n", "print\"Overall Nusselt number is \"\n", "NuL=hx*D/k\n", - "print\"NuL=\",NuL" + "print\"NuL=\",NuL\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n" ] }, { @@ -212,7 +261,7 @@ }, { "cell_type": "code", - "execution_count": 3, + "execution_count": 4, "metadata": { "collapsed": false }, @@ -236,6 +285,7 @@ } ], "source": [ + " \n", "import math\n", " \n", "print\"Introduction to heat transfer by S.K.Som, Chapter 5, Example 7\"\n", @@ -274,7 +324,21 @@ "#Q is the heat loss from the plate\n", "print\"The heat loss from the plate in W is\"\n", "Q=hbar*A*(Ts-Tinf)\n", - "print\"Q=\",Q" + "print\"Q=\",Q\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n" ] }, { @@ -306,6 +370,7 @@ } ], "source": [ + " \n", "import math\n", " \n", "print\"Introduction to heat transfer by S.K.Som, Chapter 5, Example 8\"\n", @@ -333,7 +398,28 @@ "#I is the current flow.\n", "print\"The current in Ampere is\"\n", "I=(Q/(R*L))**0.5\n", - "print\"I=\",I" + "print\"I=\",I\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n" ] } ], diff --git a/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter5_2AAnLS8.ipynb b/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter5_2AAnLS8.ipynb deleted file mode 100644 index 1751c7ce..00000000 --- a/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter5_2AAnLS8.ipynb +++ /dev/null @@ -1,447 +0,0 @@ -{ - "cells": [ - { - "cell_type": "markdown", - "metadata": { - "collapsed": true - }, - "source": [ - "# Chapter 5:Convection" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex5.3:pg-206" - ] - }, - { - "cell_type": "code", - "execution_count": 1, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 5, Example 3\n", - "Reynolds number is\n", - "ReL= 55263.1578947\n", - "The average heat transfer coefficient over a length(L)= 1m ,in W/m**2 is\n", - "hbarL= 4.16\n", - "The rate of heat transfer in W/m of width is\n", - "Q= 332.8\n" - ] - } - ], - "source": [ - " \n", - "import math \n", - "from scipy.integrate import quad\n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 5, Example 3\"\n", - "#Air at temprature (T1=20°C) and 1 atmospheric pressure flows over a flat plate with a free stream velocity(Uinf) of 1m/s.\n", - "Uinf=1;\n", - "T1=20;\n", - "#The length of plate is 1m and is heated over its entire length to a constant temprature of T2=100°C.\n", - "T2=100;\n", - "#For air at 20°C(The mean temprature of 100°C and 20°C),viscosity(mu=1.9*10**-5kg/(m*s)),density(rho=1.05kg/m**3),conductivity(k=0.03W/(m*K)),specific heat(cp=1.007kJ/(kg*K))\n", - "#Prandtl number is Pr=0.7\n", - "mu=1.9*10**-5;\n", - "rho=1.05;\n", - "k=0.03;\n", - "cp=1.007;\n", - "Pr=0.7;\n", - "#For laminar flow over a plate Nusselt number is Nux=0.332*Rex**0.5*Pr**(1/3)\n", - "#The boundary layer flow over a flat plate will be laminar if Reynolds number is Rex=(rho*Uinf*x)/mu<5*10**5\n", - "#First of all we have to check whether the flow is laminar or not.\n", - "#Let us check at x=1m\n", - "x=1.0;\n", - "print\"Reynolds number is\"\n", - "ReL=(rho*Uinf*x)/mu\n", - "print\"ReL=\",ReL\n", - "#There fore the flow is laminar and we can use the relationships of Nux,\n", - "#Thus Rex=(1.05*1*x)/(1.9*10**-5)=0.5526*10**5*x\n", - "#Therefore we can write Nux=(hx*x/k)=0.332*(0.5526*10**5*x)**0.5*Pr**(1/3)....or hx=2.08*x**(-1/2) W/(m**2*°C)\n", - "#hbarL is the average heat transfer coefficient over a length(L)\n", - "print\"The average heat transfer coefficient over a length(L)= 1m ,in W/m**2 is\"\n", - "L=1;\n", - "hbarL=(1.0/L)*quad(lambda x:2.08*x**(-1/2.0),0,L)[0]\n", - "print\"hbarL=\",hbarL\n", - "#Q is the rate of heat transfer\n", - "print\"The rate of heat transfer in W/m of width is\"\n", - "Q=hbarL*L*(T2-T1)\n", - "print\"Q=\",Q\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex5.4:pg-207" - ] - }, - { - "cell_type": "code", - "execution_count": 2, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 5, Example 4\n", - "The local heat transfer coefficient hx is hx=27.063*U**0.85\n", - "The minimum flow velocity in m/s is\n", - "U= 15.4806813943\n" - ] - } - ], - "source": [ - " \n", - "import math\n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 5, Example 4\"\n", - "#Air at atmospheric pressure is required to flow over a circuit board to cool the electronics element mounted on it.\n", - "#Chip has length (L)=3mm and width(B)=3mm located x=0.1m from the leading edge\n", - "L=0.003;#in metre\n", - "B=0.003;#in metre\n", - "x=0.1;\n", - "#The Nusselt no. is given by Nux=0.06*Rex**0.85*Pr**0.33\n", - "#The chip has to dissipate E=50mW of energy while its surface temprature has to be kept below temprature,Ts=45°C and free strem Temptrature of air is Tinf=25°C\n", - "Ts=45;\n", - "Tinf=25;\n", - "E=50*10**-3;#in watt\n", - "#For air ,density(rho=1.2kg/m**3),viscosity(mu=1.8*10**5kg/(m*s)),conductivity(k=0.03W/(m*K)) and specific heat(cp=1000J/(kg*K))\n", - "rho=1.2;\n", - "mu=1.8*10**5;\n", - "k=0.03;\n", - "cp=1000;\n", - "#Let the minimum flow velocity be U.\n", - "#The local heat transfer coefficient hx where the chip is mounted is determined as hx=(k/x)*0.06*(rho*U*x/mu)**0.85*(mu*cp/k)**0.33\n", - "print\"The local heat transfer coefficient hx is hx=27.063*U**0.85\"\n", - "#from an enrgy balance we can write as E=27.063*U**0.85*L*B*(Ts-Tinf)\n", - "print\"The minimum flow velocity in m/s is\"\n", - "U=(E/(27.063*L*B*(Ts-Tinf)))**(1/0.85)\n", - "print\"U=\",U\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex5.6:pg-208" - ] - }, - { - "cell_type": "code", - "execution_count": 3, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 5, Example 6\n", - "mdot= 0.0235619449019\n", - "(dTb/dx)in °C/m is\n", - "Y= 26.6666666667\n", - "Therefore Exit bulk mean temprature Tb2 in °C is\n", - "Tb2= 83.3333333333\n", - "Heat flux(hx) in W/(m**2*°C) is \n", - "hx= 100\n", - "Overall Nusselt number is \n", - "NuL= 87.7192982456\n" - ] - } - ], - "source": [ - " \n", - "import math\n", - " \n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 5, Example 6\"\n", - "#Air at 1atm pressure and temprature(Tin)=30°C enters a tube of 25mm diameter(D) with a velocity(U) of 10m/s\n", - "D=0.025;#in metre\n", - "U=10;\n", - "Tin=30;\n", - "#Tube is heated so that a constant heat flux(q) of 2kW/m**2 is maintained at the wall whose temprature is deltaT=20°C above the bulk mean air temprature through the length of tube \n", - "#Let Tw-Tb=T\n", - "q=2000;\n", - "deltaT=20;\n", - "#The length(L)= 2m\n", - "L=2;\n", - "#For air density(rho=1.2kg/m**3),specific heat(cp=1000J/(kg*K))\n", - "rho=1.2;\n", - "cp=1000;\n", - "#From an energy balance of a control volume of air we get mdot*cp*(Tb+(dTb/dx)*deltax-Tb)=q*pi*D*deltax or (dTb/dx)=(q*pi*D)/(mdot*cp)\n", - "#mass flow rate=mdot\n", - "mdot=rho*math.pi*D**2*U;\n", - "print\"mdot=\",mdot\n", - "#let (dTb/dx)=Y\n", - "print\"(dTb/dx)in °C/m is\"\n", - "Y=(4*q*math.pi*D)/(mdot*cp)\n", - "print\"Y=\",Y\n", - "#Tb2 is Exit bulk mean temprature\n", - "print\"Therefore Exit bulk mean temprature Tb2 in °C is\"\n", - "Tb2=Tin+Y*2\n", - "print\"Tb2=\",Tb2\n", - "#Again we can write at any section of the tube hx*(Tw-Tb)=q or hx=q/(Tw-Tb)\n", - "#hx is heat flux\n", - "print\"Heat flux(hx) in W/(m**2*°C) is \"\n", - "hx=q/(deltaT)\n", - "print\"hx=\",hx\n", - "#Since Tw-Tb remains the same,The heat transfer coefficient at all sections are the same\n", - "#Now Overall Nusselt number,NuL=hx*D/k\n", - "#The thermal conductivity of air at mean temprature of (30+83.4)/2=56.7°C is k=0.0285 W/(m*K)\n", - "k=0.0285;\n", - "print\"Overall Nusselt number is \"\n", - "NuL=hx*D/k\n", - "print\"NuL=\",NuL\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex5.7:pg-210" - ] - }, - { - "cell_type": "code", - "execution_count": 4, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 5, Example 7\n", - "Beta(The volumetric coefficient of expansion in K**-1 is\n", - "Beta= 0\n", - "Grashoff number is\n", - "Gr= 0.0\n", - "The average nusselt number is\n", - "NuHbar= 0.13\n", - "Heat flux hbar in W/(m**2*°C)\n", - "hbar= 0.00169\n", - "The heat loss from the plate in W is\n", - "Q= 0.4394\n" - ] - } - ], - "source": [ - " \n", - "import math\n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 5, Example 7\"\n", - "#A wall is exposed to nitrogen at one atmospheric pressure and temprature,Tinf=4°C.\n", - "Tinf=4;\n", - "#The wall is H=2.0m high and B=2.5m wide and is maintained at temprature,Ts=56°C\n", - "Ts=56;\n", - "H=2;\n", - "B=2.5;\n", - "A=H*B;#area is(A)\n", - "#The average nusselt number NuHbar over the height of the plate is given by NuHbar=0.13*(Gr*Pr)**(1/3)\n", - "#The properties of nitrogen at mean film temprature(Tf) is (56+4)/2=30°C are given as density(rho=1.142kg/m**3) ,conductivity(k=0.026W/(m*K)),\n", - "#kinematic viscosity(nu=15.630*10**-6 m**2/s) ,Prandtl number(Pr=0.713)\n", - "rho=1.142;\n", - "k=0.026;\n", - "nu=15.630*10**-6;\n", - "Pr=0.713;\n", - "Tf=30;\n", - "#We first have to detrmine the value of Grashoff number,Gr.In consideration of nitrogen as an ideal gas,we can write\n", - "#Beta(The volumetric coefficient of expansion)=1/T\n", - "print\"Beta(The volumetric coefficient of expansion in K**-1 is\"\n", - "Beta=1/(273+Tf)\n", - "print\"Beta=\",Beta\n", - "#Now Gr=(g*Beta*(Ts-Tinf)*H**3)/nu**2\n", - "g=9.81;#acceleration due to gravity\n", - "print\"Grashoff number is\"\n", - "Gr=(g*Beta*(Ts-Tinf)*H**3)/nu**2\n", - "print\"Gr=\",Gr\n", - "print\"The average nusselt number is\"\n", - "NuHbar=0.13*(Gr*Pr)**(1/3)\n", - "print\"NuHbar=\",NuHbar\n", - "#hbar is the heat flux\n", - "print\"Heat flux hbar in W/(m**2*°C)\"\n", - "hbar=NuHbar*k/H\n", - "print\"hbar=\",hbar\n", - "#Q is the heat loss from the plate\n", - "print\"The heat loss from the plate in W is\"\n", - "Q=hbar*A*(Ts-Tinf)\n", - "print\"Q=\",Q\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex5.8:pg-211" - ] - }, - { - "cell_type": "code", - "execution_count": 1, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 5, Example 8\n", - "The heat flux in W/(m**2*K) is\n", - "hbar 120.0\n", - "The heat loss from the wire is Q=hbar*pi*D*L*(Twire-Tair) in Watt\n", - "Q= 1.88495559215\n", - "The current in Ampere is\n", - "I= 17.7245385091\n" - ] - } - ], - "source": [ - " \n", - "import math\n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 5, Example 8\"\n", - "#Eletric current passes through a L=0.5m long horizontal wire of D=0.1mm diameter.\n", - "L=0.5;\n", - "D=0.1*10**-3;\n", - "#The wire is to be maintained at temprature,Twire=400K and the air is at temprature,Tair=300K.\n", - "Twire=400;\n", - "Tair=300;\n", - "#The resistance of the wire(R) is 0.012ohm per meter.Nusselt number(NuL) over the length of wire to be 0.4.\n", - "NuL=0.4;\n", - "R=0.012;\n", - "#At mean temprature of Tf=350K, The thermal conductivity of air is k=0.03W/(m*K)\n", - "k=0.03;\n", - "#Nusselt number is NuL=hbar*D/k\n", - "#hbar is the heat flux\n", - "print\"The heat flux in W/(m**2*K) is\"\n", - "hbar=NuL*k/D\n", - "print\"hbar\",hbar\n", - "#Q is the heat loss from the wire\n", - "print\"The heat loss from the wire is Q=hbar*pi*D*L*(Twire-Tair) in Watt\"\n", - "Q=hbar*math.pi*D*L*(Twire-Tair)\n", - "print\"Q=\",Q\n", - "#At steady state the ohmic loss in the wire equals the heat loss from its surface Therfore I**2*R=Q\n", - "#I is the current flow.\n", - "print\"The current in Ampere is\"\n", - "I=(Q/(R*L))**0.5\n", - "print\"I=\",I\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n" - ] - } - ], - "metadata": { - "kernelspec": { - "display_name": "Python 2", - "language": "python", - "name": "python2" - }, - "language_info": { - "codemirror_mode": { - "name": "ipython", - "version": 2 - }, - "file_extension": ".py", - "mimetype": "text/x-python", - "name": "python", - "nbconvert_exporter": "python", - "pygments_lexer": "ipython2", - "version": "2.7.11" - } - }, - "nbformat": 4, - "nbformat_minor": 0 -} diff --git a/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter6.ipynb b/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter6.ipynb index 5a31da63..1c386970 100644 --- a/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter6.ipynb +++ b/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter6.ipynb @@ -18,7 +18,7 @@ }, { "cell_type": "code", - "execution_count": 10, + "execution_count": 3, "metadata": { "collapsed": false }, @@ -45,6 +45,7 @@ } ], "source": [ + " \n", "import math\n", " \n", "print\"Introduction to heat transfer by S.K.Som, Chapter 6, Example 1\"\n", @@ -54,7 +55,7 @@ "mu=0.1;\n", "b=0.005; #in metre\n", " #Umax is maximum velocity\n", - " Umax=(3/2)*Uav\n", + " Umax=(3.0/2)*Uav\n", "print\"Umax in m/s is\"\n", "Umax=(3/2)*Uav\n", "print\"Umax=\",Umax\n", @@ -81,7 +82,31 @@ " #Since pressure drop is considered at a distance of 2m so L=2m\n", "L=2;\n", "deltaP=(-X)*L\n", - "print\"deltaP=\",deltaP" + "print\"deltaP=\",deltaP\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n" ] }, { @@ -93,7 +118,7 @@ }, { "cell_type": "code", - "execution_count": 14, + "execution_count": 2, "metadata": { "collapsed": false }, @@ -113,6 +138,7 @@ } ], "source": [ + " \n", "import math\n", " \n", "print\"Introduction to heat transfer by S.K.Som, Chapter 6, Example 3\"\n", @@ -133,7 +159,28 @@ " #The viscosity of oil is mu=(pi*D**4*X)/(128*Q*dz)\n", "print\"The viscosity of oil(mu)in kg/(m*s)\"\n", "mu=(math.pi*D**4*X)/(128*Q)\n", - "print\"mu=\",mu" + "print\"mu=\",mu\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n" ] }, { @@ -145,7 +192,7 @@ }, { "cell_type": "code", - "execution_count": 16, + "execution_count": 1, "metadata": { "collapsed": false }, @@ -154,7 +201,7 @@ "name": "stdout", "output_type": "stream", "text": [ - " Introduction to heat transfer by S.K.Som, Chapter 6, Example 7\n", + "Introduction to heat transfer by S.K.Som, Chapter 6, Example 7\n", "The maximum length of plate in m is \n", "L= 2.5\n", "The average skin friction coefficient is\n", @@ -165,6 +212,7 @@ } ], "source": [ + " \n", "import math\n", " \n", "print\"Introduction to heat transfer by S.K.Som, Chapter 6, Example 7\"\n", @@ -188,7 +236,26 @@ " #Fd is drag force\n", "print\"Drag force on one side of plate in N is\"\n", "Fd=cfL*(rhoair*Uinf**2/2)*B*L\n", - "print\"Fd=\",Fd" + "print\"Fd=\",Fd\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n" ] }, { @@ -200,7 +267,7 @@ }, { "cell_type": "code", - "execution_count": 17, + "execution_count": 2, "metadata": { "collapsed": false }, @@ -224,6 +291,7 @@ } ], "source": [ + " \n", "import math\n", " \n", "print\"Introduction to heat transfer by S.K.Som, Chapter 6, Example 10\"\n", @@ -252,7 +320,21 @@ " #The turbulent boundary layer thickness at the trailing edge is given by delta=L*(0.379/ReL**(1/5))\n", "print\"The turbulent boundary layer thickness at the trailing edge in metre is \"\n", "delta=L*(0.379/ReL**(1/5))\n", - "print\"delta=\",delta" + "print\"delta=\",delta\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n" ] } ], diff --git a/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter6_lGPDUWp.ipynb b/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter6_lGPDUWp.ipynb deleted file mode 100644 index 1c386970..00000000 --- a/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter6_lGPDUWp.ipynb +++ /dev/null @@ -1,362 +0,0 @@ -{ - "cells": [ - { - "cell_type": "markdown", - "metadata": { - "collapsed": true - }, - "source": [ - "# Chapter 06:Incompressible viscous flow: A brief review" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex6.1:pg-226" - ] - }, - { - "cell_type": "code", - "execution_count": 3, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 6, Example 1\n", - "Umax in m/s is\n", - "Umax= 1.6\n", - "The shear stress T in N/m**2\n", - "T= 64.0\n", - "(dp/dx) in N/m**3 is\n", - "X= -19200.0\n", - "The Shear stress at a distance of 0.002m from the lower plate in N/m**2\n", - "t= -57.6\n", - "The shear stress at a distance of 0.002m from the upper plate in N/m**2\n", - "t= 57.6\n", - "The opposite signs in t represents the opposite directions.The plus sign is in the direction of flow and the minus sign is in the direction opposite to the flow \n", - "The pressure drop over a distance of 2m in N/m**2 is\n", - "deltaP= 38400.0\n" - ] - } - ], - "source": [ - " \n", - "import math\n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 6, Example 1\"\n", - " #Oil of specific gravity 0.90 and dynamic viscosity (mu=0.1Pa*s) flows between two fixed plates kept 2*b=10mm apart,So b=5mm.\n", - "#The average velocity is Uav=1.60m/s\n", - "Uav=1.60;\n", - "mu=0.1;\n", - "b=0.005; #in metre\n", - " #Umax is maximum velocity\n", - " Umax=(3.0/2)*Uav\n", - "print\"Umax in m/s is\"\n", - "Umax=(3/2)*Uav\n", - "print\"Umax=\",Umax\n", - " #The shear stress at the plate is given by T=2*µ*(Umax/b)\n", - "print\"The shear stress T in N/m**2\"\n", - "T=2*mu*(Umax/b) \n", - " #The shear sress at a distance from plate is given by t=y*(dp/dx)\n", - "#(dp/dx)=X=-3*mu*(Uav/b**2)\n", - "print\"T=\",T\n", - "print\"(dp/dx) in N/m**3 is\"\n", - "X=-3*mu*(Uav/b**2)\n", - " #Taking modulus of X by multipying it with negative sign.\n", - "print\"X=\",X\n", - "print\"The Shear stress at a distance of 0.002m from the lower plate in N/m**2\"\n", - "y=b-0.002;\n", - "t=y*(X) #NOTE:Answer given in the book is incorrect (Calculation mistake)\n", - "print\"t=\",t\n", - "print\"The shear stress at a distance of 0.002m from the upper plate in N/m**2\"\n", - "t=-y*(X) #NOTE:Answer given in the book is incorrect (Calculation mistake)\n", - "print\"t=\",t\n", - "print\"The opposite signs in t represents the opposite directions.The plus sign is in the direction of flow and the minus sign is in the direction opposite to the flow \"\n", - " #deltaP is the pressure drop\n", - "print\"The pressure drop over a distance of 2m in N/m**2 is\"\n", - " #Since pressure drop is considered at a distance of 2m so L=2m\n", - "L=2;\n", - "deltaP=(-X)*L\n", - "print\"deltaP=\",deltaP\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex6.3:pg-229" - ] - }, - { - "cell_type": "code", - "execution_count": 2, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 6, Example 3\n", - "The rate of change of pressure with respect to length in N/m**3\n", - "X= 2000\n", - "Flow rate(Q) in m**3/s is)\n", - "Q= 0.00333333333333\n", - "The viscosity of oil(mu)in kg/(m*s)\n", - "mu= 0.0920388472731\n" - ] - } - ], - "source": [ - " \n", - "import math\n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 6, Example 3\"\n", - " #Oil of specific gravity (sg)=0.90 is discharged at a rate(mdot)=3kg/s under a pressure difference dp=10KN/m**2 over a length dz=5m of a pipe having a diameter(D) of 50mm.\n", - "dp=10*10**3; #in N/m**2\n", - "dz=5;\n", - "D=0.05; #in metre\n", - "mdot=3;\n", - "sg=0.90;\n", - " #X=dp/dz is the rate of change of pressure\n", - "print\"The rate of change of pressure with respect to length in N/m**3\"\n", - "X=dp/dz\n", - "print\"X=\",X\n", - " #Flow rate is Q\n", - "print\"Flow rate(Q) in m**3/s is)\"\n", - "Q=mdot/(sg*10**3)\n", - "print\"Q=\",Q\n", - " #The viscosity of oil is mu=(pi*D**4*X)/(128*Q*dz)\n", - "print\"The viscosity of oil(mu)in kg/(m*s)\"\n", - "mu=(math.pi*D**4*X)/(128*Q)\n", - "print\"mu=\",mu\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex6.7:pg-250 " - ] - }, - { - "cell_type": "code", - "execution_count": 1, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 6, Example 7\n", - "The maximum length of plate in m is \n", - "L= 2.5\n", - "The average skin friction coefficient is\n", - "cfL= 1.328\n", - "Drag force on one side of plate in N is\n", - "Fd= 21.5136\n" - ] - } - ], - "source": [ - " \n", - "import math\n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 6, Example 7\"\n", - " #A flat plate B=1.2m wide and of length L is kept parallel to a uniform stream of air of velocity Uinf=3m/s in a wind tunnel.\n", - "Uinf=3;\n", - "B=1.2;\n", - " #If it is desired to have a laminar boundary layer only on the plate \n", - "#Assume that the laminar flow exists up to a reynold number(ReL)=5*10**5.Take density of air as rhoair=1.2kg/m**3 and viscosity of air as nuair=1.5*10**-5 m**2/s.\n", - "nuair=1.5*10**-5;\n", - "rhoair=1.2;\n", - "ReL=5*10**5;\n", - " #For maximum length of the plate reynolds number is ReL=Uinf*L/nuair\n", - "#so L=ReL*nuair/Uinf\n", - "print\"The maximum length of plate in m is \"\n", - "L=ReL*nuair/Uinf\n", - "print\"L=\",L\n", - " #The average skin friction coefficient is cfL=1.328/(ReL)**(1/2)\n", - "print\"The average skin friction coefficient is\"\n", - "cfL=1.328/(ReL)**(1/2)\n", - "print\"cfL=\",cfL\n", - " #Fd is drag force\n", - "print\"Drag force on one side of plate in N is\"\n", - "Fd=cfL*(rhoair*Uinf**2/2)*B*L\n", - "print\"Fd=\",Fd\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex6.10:pg-268 " - ] - }, - { - "cell_type": "code", - "execution_count": 2, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 6, Example 10\n", - "Wind velocity(Uinf)in m/s is\n", - "Uinf= 10\n", - "Reynolds number is\n", - "ReL= 4000000.0\n", - "Friction coefficient is\n", - "CbarfL= 0.0735645\n", - "Drag force on one side of the plate per unit metre width in Newton is \n", - "FD= 26.48322\n", - "The turbulent boundary layer thickness at the trailing edge in metre is \n", - "delta= 2.274\n" - ] - } - ], - "source": [ - " \n", - "import math\n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 6, Example 10\"\n", - " #Wind at a speed of U=36km/hr blows over a flat plate of length,L=6m .If the density and kinematic viscosity of air are rho=1.2kg/m**3 and mu=1.5*10**-5m**2/s respectively.\n", - "U=36;\n", - "L=6;\n", - "rho=1.2;\n", - "mu=1.5*10**-5;\n", - " #Wind velocity in m/s is Uinf\n", - "print\"Wind velocity(Uinf)in m/s is\"\n", - "Uinf=U*1000/3600\n", - "print\"Uinf=\",Uinf\n", - " #Reynolds number is given by ReL=L*Uinf/mu\n", - "print\"Reynolds number is\"\n", - "ReL=L*Uinf/mu\n", - "print\"ReL=\",ReL\n", - " #We consider that transition of boundary layer takes place from laminar to turbulent takes place at ReL=5*10**5.\n", - "#Therfore the corresponding friction coefficient is given by CbarfL=(0.074-ReL**(1/5))-(1742/ReL)\n", - "print\"Friction coefficient is\"\n", - "CbarfL=(0.074/ReL**(1/5))-(1742/ReL)\n", - "print\"CbarfL=\",CbarfL\n", - " #Drag force on one side of the plate per unit metre width is given by FD=CbarfL*rho*Uinf**2*L/2\n", - "print\"Drag force on one side of the plate per unit metre width in Newton is \"\n", - "FD=CbarfL*rho*Uinf**2*L/2\n", - "print\"FD=\",FD\n", - " #The turbulent boundary layer thickness at the trailing edge is given by delta=L*(0.379/ReL**(1/5))\n", - "print\"The turbulent boundary layer thickness at the trailing edge in metre is \"\n", - "delta=L*(0.379/ReL**(1/5))\n", - "print\"delta=\",delta\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n" - ] - } - ], - "metadata": { - "kernelspec": { - "display_name": "Python 2", - "language": "python", - "name": "python2" - }, - "language_info": { - "codemirror_mode": { - "name": "ipython", - "version": 2 - }, - "file_extension": ".py", - "mimetype": "text/x-python", - "name": "python", - "nbconvert_exporter": "python", - "pygments_lexer": "ipython2", - "version": "2.7.11" - } - }, - "nbformat": 4, - "nbformat_minor": 0 -} diff --git a/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter7.ipynb b/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter7.ipynb index bffd25f6..85b7eec5 100644 --- a/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter7.ipynb +++ b/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter7.ipynb @@ -42,6 +42,7 @@ } ], "source": [ + " \n", "import math \n", " \n", "print\"Introduction to heat transfer by S.K.Som, Chapter 7, Example 1\"\n", @@ -114,7 +115,11 @@ } ], "source": [ - "import math\n", + " \n", + " \n", + " \n", + " \n", + " import math\n", " \n", "print\"Introduction to heat transfer by S.K.Som, Chapter 7, Example 2\"\n", "#Atmospheric air at temprature,Tinf=300K and with a free stream Velocity Uinf=30m/s flows over a flat plate parallel to a side of length(L)=2m.\n", @@ -156,7 +161,24 @@ "A=L*B;\n", "print\"The rate of heat transfer per unit width in W is\"\n", "Q=hbarL*A*(Tw-Tinf)\n", - "print\"Q=\",Q" + "print\"Q=\",Q\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n" ] }, { @@ -196,7 +218,11 @@ } ], "source": [ - "import math\n", + " \n", + " \n", + " \n", + " \n", + " import math\n", " \n", "print\"Introduction to heat transfer by S.K.Som, Chapter 7, Example 3\"\n", "#Air at a pressure of 101kPa and temprature,Tinf=20°C flows with a velocity(Uinf) of 5m/s over a flat plate whose temprature is kept constant at Tw=140°C.\n", @@ -246,7 +272,33 @@ "#Q is the rate of heat transfer\n", "print\"The rate of heat transfer per unit width in W is\"\n", "Q=h*A*(Tw-Tinf)\n", - "print\"Q=\",Q" + "print\"Q=\",Q\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n" ] }, { @@ -288,7 +340,11 @@ } ], "source": [ - "import math\n", + " \n", + " \n", + " \n", + " \n", + " import math\n", " \n", "print\"Introduction to heat transfer by S.K.Som, Chapter 7, Example 4\"\n", "#Castor oil at temprature,Tinf=36°C flows over a heated plate of length,L=6m and breadth,B=1m at velocity,Uinf=0.06m/s\n", @@ -336,7 +392,29 @@ "A=L*B;\n", "print\"(c)The rate of heat transfer in W is\"\n", "Q=hbarL*A*(Tw-Tinf)\n", - "print\"Q=\",Q" + "print\"Q=\",Q\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n" ] }, { @@ -369,7 +447,11 @@ } ], "source": [ - "import math\n", + " \n", + " \n", + " \n", + " \n", + " import math\n", " \n", "print\"Introduction to heat transfer by S.K.Som, Chapter 7, Example 5\"\n", "#A flat plate of width B=1m is maintained at a uniform surface temprtaure(Tw)=225°C\n", @@ -405,7 +487,24 @@ "#If qm be the power generation in W/m**2 within the module ,we can write from energy balance qm*(t/0.1000)*(l/0.1000)*(B)=hbarL*(t/0.1000)*(B)*(Tw-Tinf)\n", "print\"The required power generation in W/m**3 is\"\n", "qm=(hL*(l/0.1000)*(B)*(Tw-Tinf))/((t/0.1000)*(l/0.1000)*(B))\n", - "print\"qm=\",qm" + "print\"qm=\",qm\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n" ] }, { @@ -441,7 +540,11 @@ } ], "source": [ - "import math\n", + " \n", + " \n", + " \n", + " \n", + " import math\n", "\n", "print\"Introduction to heat transfer by S.K.Som, Chapter 7, Example 6\"\n", "#An aircraft is moving at a velocity of Uinf=150m/s in air at an altitude where the pressure is 0.7bar and the temprature is Tinf=-5°C.\n", @@ -476,7 +579,21 @@ "#Therefore we can write Surface temprature of wing, Tw=Tinf+(Qr/(2*hbarL))\n", "print\"Surface temprature of wing in kelvin is\"\n", "Tw=(273+Tinf)+(Qr/(2*hbarL))\n", - "print\"Tw=\",Tw" + "print\"Tw=\",Tw\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n" ] }, { @@ -516,7 +633,11 @@ } ], "source": [ - "import math\n", + " \n", + " \n", + " \n", + " \n", + " import math\n", " \n", "print\"Introduction to heat transfer by S.K.Som, Chapter 7, Example 7\"\n", "#A fine wire having a diameter(D)=0.04mm is placed in an air stream at temprature,Tinf=25°C having a flow velocity of Uinf=60m/s perpendicular to wire.\n", @@ -558,7 +679,32 @@ "#Heat transfer per unit length(qL) is given by pi*D*hbar*(Tw-Tinf)\n", "print\"Heat transfer per unit length in W/m is\"\n", "qL=math.pi*(D*10**-3)*hbar*(Tw-Tinf)\n", - "print\"qL=\",qL" + "print\"qL=\",qL\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n" ] }, { @@ -596,7 +742,11 @@ } ], "source": [ - "import math\n", + " \n", + " \n", + " \n", + " \n", + " import math\n", "\n", "print\"Introduction to heat transfer by S.K.Som, Chapter 7, Example 8\"\n", "#Mercury and a light oil flowing at Uinf=4mm/s in a smooth tube having diameter(D)=25mm at a bulk temprature of 80°C.\n", @@ -633,7 +783,24 @@ "#Ltoil is the thermal entry length for oil\n", "print\"The thermal entry length for oil in m is\"\n", "Ltoil=0.05*Reoil*Proil*D\n", - "print\"Ltoil=\",Ltoil" + "print\"Ltoil=\",Ltoil\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n" ] }, { @@ -673,7 +840,11 @@ } ], "source": [ - "import math\n", + " \n", + " \n", + " \n", + " \n", + " import math\n", " \n", "print\"Introduction to heat transfer by S.K.Som, Chapter 7, Example 9\"\n", "#Air at one atmospheric pressure and temprature(Tbi=75°C) enters a tube of internal diameter(D)=4.0mm with average velocity(U)=2m/s\n", @@ -724,7 +895,21 @@ "#Let Twe be the surface temprature at the exit plane.Then we can write hL*(Twe-Tbo)=qw\n", "print\"The tube surface temprature at the exit plane in °C is \"\n", "Twe=Tbo+(qw/hL)\n", - "print\"Twe=\",Twe" + "print\"Twe=\",Twe\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n" ] }, { @@ -767,7 +952,11 @@ } ], "source": [ - "import math\n", + " \n", + " \n", + " \n", + " \n", + " import math\n", " \n", "print\"Introduction to heat transfer by S.K.Som, Chapter 7, Example 10\"\n", "#Air at one atmospheric pressure and temprature(Tbi=75°C) enters a tube of internal diameter(D)=4.0mm with average velocity(U)=2m/s\n", @@ -822,7 +1011,18 @@ "#Let Twe be the surface temprature at the exit plane.Then we can write hL*(Twe-Tbo)=qw\n", "print\"The tube surface temprature at the exit plane in °C is \"\n", "Twe=Tbo+(qw/hL)\n", - "print\"Twe=\",Twe" + "print\"Twe=\",Twe\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n" ] }, { @@ -867,7 +1067,11 @@ } ], "source": [ - "import math\n", + " \n", + " \n", + " \n", + " \n", + " import math\n", " \n", "print\"Introduction to heat transfer by S.K.Som, Chapter 7, Example 11\"\n", "#Liquid sulphur di oxide in a saturated state flows inside a L=5m long tube and D=25mm internal diameter with a mass flow rate(mdot) of 0.15 kg/s.\n", diff --git a/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter7_Ie2FcUI.ipynb b/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter7_Ie2FcUI.ipynb deleted file mode 100644 index 85b7eec5..00000000 --- a/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter7_Ie2FcUI.ipynb +++ /dev/null @@ -1,1176 +0,0 @@ -{ - "cells": [ - { - "cell_type": "markdown", - "metadata": { - "collapsed": true - }, - "source": [ - "# Chapter 07:Principles of forced convection" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex7.1:pg-296" - ] - }, - { - "cell_type": "code", - "execution_count": 1, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 7, Example 1\n", - "First we check from reynolds no. that the flow is laminar or tubulent\n", - "Reynold number is\n", - "Re= 20000.0\n", - "which is less than critical reynolds number,So the flow is laminar.\n", - "The average nusselt number over the entire length under the situation is given by NuL=0.664*Re**0.5*Pr**(1/3)\n", - "NuL= 93.9037805416\n", - "Heat flux in W/(m**2*K) is\n", - "h= 2.72320963571\n", - "The rate of heat transfer per unit width in W is\n", - "Q= 408.481445356\n" - ] - } - ], - "source": [ - " \n", - "import math \n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 7, Example 1\"\n", - "#Engine oil at temprature,Tinf=60°C with a velocity of Uinf=1m/s flows over plate of length(L)=5m whose temprature(Tw)=30°C\n", - "Tw=30;\n", - "L=5;\n", - "Uinf=1;\n", - "Tinf=60;\n", - "#The properties at a film temprature of 45°C are as follows density(rho=870kg/m**3),Prandtl number(Pr=2850),conductivity(k=0.145W/(m*°C)),kinematic viscosity(nu=250*10**-6m**2/s).\n", - "rho=870;\n", - "Pr=2850;\n", - "k=0.145;\n", - "nu=250*10**-6;\n", - "print\"First we check from reynolds no. that the flow is laminar or tubulent\"\n", - "#Reynolds number is given by Re=(Uinf*L)/nu\n", - "print\"Reynold number is\"\n", - "Re=(Uinf*L)/nu\n", - "print\"Re=\",Re\n", - "print\"which is less than critical reynolds number,So the flow is laminar.\"\n", - "#NuL is the average nusselt number\n", - "print\"The average nusselt number over the entire length under the situation is given by NuL=0.664*Re**0.5*Pr**(1/3)\"\n", - "NuL=0.664*Re**0.5*Pr**(1/3)\n", - "print\"NuL=\",NuL\n", - "#Heat flux is given by h=(k/L)*NuL\n", - "print\"Heat flux in W/(m**2*K) is\"\n", - "h=(k/L)*NuL\n", - "print\"h=\",h\n", - "#The rate of heat transfer per unit width is Q=h*A*(Tinf-Tw)\n", - "#Since unit width is considerd so B=1\n", - "#Area(A)=L*B\n", - "B=1;\n", - "A=L*B;\n", - "print\"The rate of heat transfer per unit width in W is\"\n", - "Q=h*A*(Tinf-Tw)\n", - "print\"Q=\",Q" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex7.2:pg-298" - ] - }, - { - "cell_type": "code", - "execution_count": 2, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 7, Example 2\n", - "The location x in m where the transition occurs\n", - "x= 0.275\n", - "The average Nusselt number for the laminar zone is\n", - "Nux= 469.518902708\n", - "Heat flux in W/(m**2*K) is\n", - "h= 44.3908780742\n", - "The reynolds number at L=2m is\n", - "ReL= 3636363.63636\n", - "The average heat transfer coefficient over L=2m in W/(m**2*K)\n", - "hbarL= -11.322519\n", - "The rate of heat transfer per unit width in W is\n", - "Q= -2264.5038\n" - ] - } - ], - "source": [ - " \n", - " \n", - " \n", - " \n", - " import math\n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 7, Example 2\"\n", - "#Atmospheric air at temprature,Tinf=300K and with a free stream Velocity Uinf=30m/s flows over a flat plate parallel to a side of length(L)=2m.\n", - "Tinf=300;\n", - "Uinf=30;\n", - "L=2;\n", - "#It is maintained at a uniform temprature of Tw=400K.\n", - "Tw=400;\n", - "#The properties of air at the film temprature of 350K are Prandtl number(Pr=0.705),conductivity(k=0.026W/(m*°C)),kinematic viscosity(nu=16.5*10**-6m**2/s)\n", - "Pr=0.705; \n", - "k=0.026;\n", - "nu=16.5*10**-6;\n", - "#We first find the location x(for reynolds number,Re=5*10**5) where the transition occurs\n", - "#Rex is reynolds number\n", - "print\"The location x in m where the transition occurs\"\n", - "Rex=5*10**5;\n", - "x=(nu*Rex)/Uinf\n", - "print\"x=\",x\n", - "#The average Nusselt number for the laminar zone is given by Nux=0.664*Re**0.5*Pr**(1/3)\n", - "print\"The average Nusselt number for the laminar zone is\"\n", - "Nux=0.664*Rex**0.5*Pr**(1/3)\n", - "print\"Nux=\",Nux\n", - "#Heat flux is given by h=(k/x)*Nux\n", - "print\"Heat flux in W/(m**2*K) is\"\n", - "h=(k/x)*Nux\n", - "print\"h=\",h\n", - "#Reynolds number is given by ReL=(Uinf*L)/nu\n", - "print\"The reynolds number at L=2m is\"\n", - "ReL=(Uinf*L)/nu\n", - "print\"ReL=\",ReL\n", - "#The average heat transfer coefficient over L=2m is determined from hbarL=(k/L)*(0.037*(ReL)**(4/5)-871)*Pr**(1/3)\n", - "print\"The average heat transfer coefficient over L=2m in W/(m**2*K)\"\n", - "hbarL=(k/L)*(0.037*(ReL)**(4/5)-871)*Pr**(1/3)\n", - "print\"hbarL=\",hbarL\n", - "#The rate of heat transfer per unit width is Q=h*A*(Tinf-Tw)\n", - "#Since unit width is considerd so B=1\n", - "#Area(A)=L*B\n", - "B=1;\n", - "A=L*B;\n", - "print\"The rate of heat transfer per unit width in W is\"\n", - "Q=hbarL*A*(Tw-Tinf)\n", - "print\"Q=\",Q\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex7.3:pg-314" - ] - }, - { - "cell_type": "code", - "execution_count": 4, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 7, Example 3\n", - "(a)When the air flows parallel to the long side we have L=5 and the Reynolds no. becomes\n", - "ReL= 1250000.0\n", - "which is greater than critical Reynolds number.\n", - "The average heat transfer coefficient over L=5m in W/(m**2*K)\n", - "hbarL= -5.225778\n", - "The rate of heat transfer per unit width in W is\n", - "Q= -3135.4668\n", - "(b)When the air flow is parallel to the 1m side we have L=1 an the Reynolds no. becomes \n", - "which is less than critical Reynolds number.\n", - "ReL= 250000.0\n", - "Heat flux in W/(m**2*K) is\n", - "h= 9.96\n", - "The rate of heat transfer per unit width in W is\n", - "Q= 5976.0\n" - ] - } - ], - "source": [ - " \n", - " \n", - " \n", - " \n", - " import math\n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 7, Example 3\"\n", - "#Air at a pressure of 101kPa and temprature,Tinf=20°C flows with a velocity(Uinf) of 5m/s over a flat plate whose temprature is kept constant at Tw=140°C.\n", - "Tw=140;\n", - "Tinf=20;\n", - "Uinf=5;\n", - "#The properties at the film temprature of 80°C are Prandtl number(Pr=0.706),Conductivity(k=0.03W/(m*°C)),kinematic viscosity(nu=2*10**-5m**2/s)\n", - "Pr=0.706;\n", - "k=0.03;\n", - "nu=2*10**-5;\n", - "#ReL is reynolds number and L is length of flat plate\n", - "print\"(a)When the air flows parallel to the long side we have L=5 and the Reynolds no. becomes\"\n", - "L=5;\n", - "ReL=(Uinf*L)/nu\n", - "print\"ReL=\",ReL\n", - "print\"which is greater than critical Reynolds number.\"\n", - "#Thus we have combined laminar and tubulent flow.\n", - "# So The average heat transfer coefficient over L=5m is determined from hbarL=(k/L)*(0.037*(ReL)**(4/5)-871)*Pr**(1/3)\n", - "print\"The average heat transfer coefficient over L=5m in W/(m**2*K)\"\n", - "hbarL=(k/L)*(0.037*(ReL)**(4/5)-871)*Pr**(1/3)\n", - "print\"hbarL=\",hbarL\n", - "#The rate of heat transfer per unit width is Q=h*A*(Tinf-Tw)\n", - "#Since width is 1m so B=1\n", - "#Area(A)=L*B\n", - "B=1;\n", - "A=L*B;\n", - "#Q is the rate of heat transfer\n", - "print\"The rate of heat transfer per unit width in W is\"\n", - "Q=hbarL*A*(Tw-Tinf)\n", - "print\"Q=\",Q\n", - "#When the air flow is parallel to the 1m side we have L=1\n", - "print\"(b)When the air flow is parallel to the 1m side we have L=1 an the Reynolds no. becomes \"\n", - "L=1;\n", - "ReL=(Uinf*L)/nu\n", - "print\"which is less than critical Reynolds number.\"\n", - "print\"ReL=\",ReL\n", - "#Thus we have laminar flow\n", - "#Heat flux is given by h=(k/L)*0.664*ReL**0.5*Pr**(1/3)\n", - "print\"Heat flux in W/(m**2*K) is\"\n", - "h=(k/L)*0.664*ReL**0.5*Pr**(1/3)\n", - "print\"h=\",h\n", - "#The rate of heat transfer per unit width is Q=h*A*(Tinf-Tw)\n", - "#Now width is 5m so B=5\n", - "#Area(A)=L*B\n", - "B=5;\n", - "A=L*B;\n", - "#Q is the rate of heat transfer\n", - "print\"The rate of heat transfer per unit width in W is\"\n", - "Q=h*A*(Tw-Tinf)\n", - "print\"Q=\",Q\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex7.4:pg-322" - ] - }, - { - "cell_type": "code", - "execution_count": 5, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 7, Example 4\n", - "(a)Reynolds number is\n", - "ReL= 6000.0\n", - "The boundary layer thickness in m is\n", - "delta= 0.387298334621\n", - "Prandtl no. is\n", - "Pr= 831.024930748\n", - "The thermal boundary layer thickness in m is\n", - "deltaT= 0.387298334621\n", - "(b)Since the prandtl number is high So Nusselt no. is\n", - "NuL= 26.2588270873\n", - "Heat flux in W/(m**2*K) is\n", - "hL= 0.919058948055\n", - "hbarL in W/(m**2*K) is\n", - "hbarL= 1.83811789611\n", - "(c)The rate of heat transfer in W is\n", - "Q= 661.7224426\n" - ] - } - ], - "source": [ - " \n", - " \n", - " \n", - " \n", - " import math\n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 7, Example 4\"\n", - "#Castor oil at temprature,Tinf=36°C flows over a heated plate of length,L=6m and breadth,B=1m at velocity,Uinf=0.06m/s\n", - "Tinf=36;\n", - "L=6;\n", - "B=1;\n", - "Uinf=0.06;\n", - "#For a surface temprature at Tw=96°C\n", - "Tw=96;\n", - "#The properties at film temprature 66°C conductivity(k=0.21W/(m*K)),kinematic viscosity(nu=6*10**-5m**2/s),Thermal diffusivity(alpha=7.22*10**-8 m**2/s)\n", - "nu=6*10**-5;\n", - "k=0.21;\n", - "alpha=7.22*10**-8;\n", - "#ReL is reynolds number\n", - "print\"(a)Reynolds number is\"\n", - "ReL=(Uinf*L)/nu\n", - "print\"ReL=\",ReL\n", - "#Therefore the boundary layer is laminar over the entire plate.\n", - "#delta is the boundary layer thickness\n", - "print\"The boundary layer thickness in m is\"\n", - "delta=(5*L)/(ReL)**0.5\n", - "print\"delta=\",delta\n", - "#Pr is prandtl number.\n", - "print\"Prandtl no. is\"\n", - "Pr=nu/alpha\n", - "print\"Pr=\",Pr\n", - "#deltaT is thermal boundary layer thickness\n", - "print\"The thermal boundary layer thickness in m is\"\n", - "deltaT=delta/(Pr**(1/3))#NOTE:Answer in the book is incorrect(calculation mistake)\n", - "print\"deltaT=\",deltaT\n", - "#NuL is the nusselt number\n", - "print\"(b)Since the prandtl number is high So Nusselt no. is\"\n", - "NuL=0.339*(ReL)**0.5*Pr**(1/3)\n", - "print\"NuL=\",NuL\n", - "#Heat flux is given by hL=(k/L)*NuL\n", - "print\"Heat flux in W/(m**2*K) is\"\n", - "hL=(k/L)*NuL\n", - "print\"hL=\",hL\n", - "#hbarL is the average heat flux over length L\n", - "print\"hbarL in W/(m**2*K) is\"\n", - "hbarL=2*hL\n", - "print\"hbarL=\",hbarL\n", - "#The rate of heat transfer is Q=h*A*(Tinf-Tw)\n", - "#Area(A)=L*B\n", - "A=L*B;\n", - "print\"(c)The rate of heat transfer in W is\"\n", - "Q=hbarL*A*(Tw-Tinf)\n", - "print\"Q=\",Q\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex7.5:pg-322" - ] - }, - { - "cell_type": "code", - "execution_count": 2, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 7, Example 5\n", - "Reynolds number is\n", - "ReL= 11181.8181818\n", - "Therefore the flow is turbulent over the module \n", - "The local heat transfer coefficient at L in W/(m**2*K)is\n", - "hL= 8.32911955901e+30\n", - "The required power generation in W/m**3 is\n", - "qm= 1.6658239118e+31\n" - ] - } - ], - "source": [ - " \n", - " \n", - " \n", - " \n", - " import math\n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 7, Example 5\"\n", - "#A flat plate of width B=1m is maintained at a uniform surface temprtaure(Tw)=225°C\n", - "Tw=225;\n", - "B=1;\n", - "#Heating is done by rectangular modules of thickness t=10mm and length l=40mm.\n", - "t=10;\n", - "l=40;\n", - "#atmospheric air at temprature,Tinf=25°C flows over the plate at velocity(Uinf)=30m/s.\n", - "Tinf=25;\n", - "Uinf=30;\n", - "#The thermophysical properties of module are conductivity(km=5.2W/(m*K)),specific heat(cp=320J/(kg/K)),density(rho=2300kg/m**3).\n", - "km=5.2;\n", - "cp=320;\n", - "rho=2300;\n", - "#Assume the air properties at the film temprature of 125°C conductivity(ka=0.031W/(m*K)),kinematic viscosity(nu=22*10**-6m**2/s),Prandtl number(Pr=0.7)\n", - "ka=0.031;\n", - "nu=22*10**-6;\n", - "Pr=0.7;\n", - "#Module is placed at a distance of 800mm from the leading edge\n", - "#The distance from leading edge to the centre-line of the module,L=800+20=820mm.\n", - "L=0.0082;#in metre\n", - "#ReL is the reynolds number \n", - "print\"Reynolds number is\"\n", - "ReL=(Uinf*L)/nu\n", - "print\"ReL=\",ReL\n", - "print\"Therefore the flow is turbulent over the module \"\n", - "#The local heat transfer coefficient at L is calculated using hL=(k/L)*0.0296*(ReL)**(4/5)*(Pr)**(1/3)\n", - "print\"The local heat transfer coefficient at L in W/(m**2*K)is\"\n", - "hL=(ka/L)*0.0296*(ReL)**(4/0.5)*(Pr)**(1/0.3)\n", - "print\"hL=\",hL\n", - "#We consider that the local heat transfer coefficient at L=0.82m remains the same over the module which extends from L=0.80m to 0.84m \n", - "#If qm be the power generation in W/m**2 within the module ,we can write from energy balance qm*(t/0.1000)*(l/0.1000)*(B)=hbarL*(t/0.1000)*(B)*(Tw-Tinf)\n", - "print\"The required power generation in W/m**3 is\"\n", - "qm=(hL*(l/0.1000)*(B)*(Tw-Tinf))/((t/0.1000)*(l/0.1000)*(B))\n", - "print\"qm=\",qm\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex7.6:pg-327" - ] - }, - { - "cell_type": "code", - "execution_count": 6, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 7, Example 6\n", - "Reynolds number is\n", - "ReL= 15000000.0\n", - "Since ReL>Rec(=5*10**5) the flow is approximated as turbulent over the entire surface of the wing \n", - "Nux= 0.0308\n", - "Nusselt number is \n", - "NubarL= 0.0308\n", - "Average heat transfer coefficient in W/(m**2*K) is\n", - "hbarL= 0.0003696\n", - "Surface temprature of wing in kelvin is\n", - "Tw= 1217800.46753\n" - ] - } - ], - "source": [ - " \n", - " \n", - " \n", - " \n", - " import math\n", - "\n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 7, Example 6\"\n", - "#An aircraft is moving at a velocity of Uinf=150m/s in air at an altitude where the pressure is 0.7bar and the temprature is Tinf=-5°C.\n", - "Tinf=-5;\n", - "Uinf=150;\n", - "#The top surface of the wing absorbs solar radiation at a rate of Qr=900W/m**2.\n", - "Qr=900;\n", - "#Considering the wing as a flat plate of length(L)=2m and to be of solid construction with a single uniform surface temprature .\n", - "L=2;\n", - "#The properties of air at 268K and 0.7 bar are conductivity(k=0.024W/(m*K)),kinematic viscosity(nu=2*10**-5m**2/s),Prandtl number(Pr=0.72)\n", - "k=0.024;\n", - "nu=2*10**-5;\n", - "Pr=0.72;\n", - "#ReL is reynolds number\n", - "print\"Reynolds number is\"\n", - "ReL=Uinf*L/nu\n", - "print\"ReL=\",ReL\n", - "#Rec is critical reynolds number\n", - "print\"Since ReL>Rec(=5*10**5) the flow is approximated as turbulent over the entire surface of the wing \"\n", - "#Nusselt number is given by Nux=0.0308*ReL**(4/5)*Pr**(1/3)\n", - "Nux=0.0308*ReL**(4/5)*Pr**(1/3);\n", - "print\"Nux=\",Nux\n", - "#NubarL is average nusselt number over length L\n", - "print\"Nusselt number is \"\n", - "NubarL=(5/4)*Nux\n", - "print\"NubarL=\",NubarL\n", - "#Average heat transfer coefficient is given by hbarL=(k/L)*NubarL\n", - "print\"Average heat transfer coefficient in W/(m**2*K) is\"\n", - "hbarL=(k/L)*NubarL\n", - "print\"hbarL=\",hbarL\n", - "#From an energy balance the airfoil at steady state,Qr*As=2*hbarL*As*(Tw-Tinf) where Qr=radiation flux,As=upper or lower surface area.\n", - "#Therefore we can write Surface temprature of wing, Tw=Tinf+(Qr/(2*hbarL))\n", - "print\"Surface temprature of wing in kelvin is\"\n", - "Tw=(273+Tinf)+(Qr/(2*hbarL))\n", - "print\"Tw=\",Tw\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex7.7:pg-331" - ] - }, - { - "cell_type": "code", - "execution_count": 7, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 7, Example 7\n", - "Reynolds number is\n", - "Re= 141.176470588\n", - "Nusselt number is\n", - "NuD= 6.85819682626\n", - "The average Heat transfer coefficient in W/(m**2*K) is\n", - "hbar= 4629.28285773\n", - "Heat transfer per unit length in W/m is\n", - "qL= 14.5433210172\n", - "If we use eq NuD=0.3+((0.62*Re**0.5*Pr**(1/3))/(1+(0.4/Pr**(2/3))**(1/4))*(1+(Re/282000)**(5/8))**(4/5)\n", - "NuD= 7.66669771975\n", - "The average Heat transfer coefficient in W/(m**2*K) is\n", - "hbar= 5175.02096083\n", - "Heat transfer per unit length in W/m is\n", - "qL= 16.2578078327\n" - ] - } - ], - "source": [ - " \n", - " \n", - " \n", - " \n", - " import math\n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 7, Example 7\"\n", - "#A fine wire having a diameter(D)=0.04mm is placed in an air stream at temprature,Tinf=25°C having a flow velocity of Uinf=60m/s perpendicular to wire.\n", - "D=0.04;\n", - "Tinf=25;\n", - "Uinf=60;\n", - "#An electric current is passed through the wire ,raising its surface temprature to Tw=50°C\n", - "Tw=50;\n", - "#For air at the film temprature of 37.5°C,conductivity(k=0.027 W/(m*K)),kinematic viscosity(nu=17*10**-6m**2/s) and Prandtl number(Pr=0.71)\n", - "k=0.027;\n", - "nu=17*10**-6;\n", - "Pr=0.71;\n", - "#Re is reynolds number\n", - "print\"Reynolds number is\"\n", - "Re=Uinf*(D*10**-3)/nu\n", - "print\"Re=\",Re\n", - "#C and n are constants\n", - "#The values of C and n are found for Re=141 are C=0.683 and n=0.466\n", - "#NuD is nusselt number\n", - "print\"Nusselt number is\"\n", - "NuD=(0.683)*Re**0.466*Pr**(1/3)\n", - "print\"NuD=\",NuD\n", - "#hbar is the average Heat transfer coefficient\n", - "print\"The average Heat transfer coefficient in W/(m**2*K) is\"\n", - "hbar=(k/(D*10**-3))*NuD\n", - "print\"hbar=\",hbar\n", - "#Heat transfer per unit length(qL) is given by pi*D*hbar*(Tw-Tinf)\n", - "print\"Heat transfer per unit length in W/m is\"\n", - "qL=math.pi*(D*10**-3)*hbar*(Tw-Tinf)\n", - "print\"qL=\",qL\n", - "#NuD is nusselt number\n", - "print\"If we use eq NuD=0.3+((0.62*Re**0.5*Pr**(1/3))/(1+(0.4/Pr**(2/3))**(1/4))*(1+(Re/282000)**(5/8))**(4/5)\"\n", - "NuD=0.3+((0.62*Re**0.5*Pr**(1/3))/(1+(0.4/Pr)**(2/3))**(1/4))*(1+(Re/282000)**(5/8))**(4/5)\n", - "print\"NuD=\",NuD\n", - "#hbar is the average Heat transfer coefficient\n", - "print\"The average Heat transfer coefficient in W/(m**2*K) is\"\n", - "hbar=(k/(D*10**-3))*NuD\n", - "print\"hbar=\",hbar\n", - "#Heat transfer per unit length(qL) is given by pi*D*hbar*(Tw-Tinf)\n", - "print\"Heat transfer per unit length in W/m is\"\n", - "qL=math.pi*(D*10**-3)*hbar*(Tw-Tinf)\n", - "print\"qL=\",qL\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex7.8:pg-334" - ] - }, - { - "cell_type": "code", - "execution_count": 8, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 7, Example 8\n", - "Reynolds number for mercury is\n", - "ReHg= 1000.0\n", - "Reynolds number for oil is\n", - "Reoil= 15.3846153846\n", - "The hydrodynamic entry length for mercury in m is\n", - "LeHg= 1.25\n", - "The hydrodynamic entry length for oil in m is\n", - "Leoil= 0.0192307692308\n", - "The thermal entry length for mercury in m is \n", - "LtHg= 0.02375\n", - "The thermal entry length for oil in m is\n", - "Ltoil= 1.63461538462\n" - ] - } - ], - "source": [ - " \n", - " \n", - " \n", - " \n", - " import math\n", - "\n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 7, Example 8\"\n", - "#Mercury and a light oil flowing at Uinf=4mm/s in a smooth tube having diameter(D)=25mm at a bulk temprature of 80°C.\n", - "Uinf=4*10**-3;#in metre\n", - "D=25*10**-3;#in metre\n", - "#The pertinent properties of the fluid at that temprature are kinematic viscosity of mercury(nuHg=1*10**-7m**2/s),kinematic viscosity of oil(nuoil=6.5*10**-6m**2/s)\n", - "#Prandtl number of mercury(PrHg=0.019),Prandtl number of oil(Proil=85).\n", - "nuHg=1*10**-7;\n", - "nuoil=6.5*10**-6;\n", - "PrHg=0.019;\n", - "Proil=85;\n", - "#ReHg is Reynolds number for mercury\n", - "print\"Reynolds number for mercury is\"\n", - "ReHg=Uinf*D/nuHg\n", - "print\"ReHg=\",ReHg\n", - "#Reoil is Reynolds number for oil\n", - "print\"Reynolds number for oil is\"\n", - "Reoil=Uinf*D/nuoil\n", - "print\"Reoil=\",Reoil\n", - "#The hydrodynamic length are given by L=0.05*Re*D\n", - "#LeHg is the hydrodynamic entry length for mercury\n", - "print\"The hydrodynamic entry length for mercury in m is\"\n", - "LeHg=0.05*ReHg*D\n", - "print\"LeHg=\",LeHg\n", - "#Leoil the hydrodynamic entry length for oil\n", - "print\"The hydrodynamic entry length for oil in m is\"\n", - "Leoil=0.05*Reoil*D\n", - "print\"Leoil=\",Leoil\n", - "#The thermal entry length are given by L=0.05*Re*Pr*D\n", - "#LtHg is the thermal entry length for mercury\n", - "print\"The thermal entry length for mercury in m is \"\n", - "LtHg=0.05*ReHg*PrHg*D\n", - "print\"LtHg=\",LtHg\n", - "#Ltoil is the thermal entry length for oil\n", - "print\"The thermal entry length for oil in m is\"\n", - "Ltoil=0.05*Reoil*Proil*D\n", - "print\"Ltoil=\",Ltoil\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex7.9:pg-336" - ] - }, - { - "cell_type": "code", - "execution_count": 9, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 7, Example 9\n", - "Reynold number is\n", - "Re= 348.623853211\n", - "Therefore the flow is laminar.The hydrodynamic entrance length in m is\n", - "Leh= 0.0697247706422\n", - "The thermal entrance length in m is\n", - "Let= 0.0488073394495\n", - "The heat transfer coefficient in W/(m**2*K) is \n", - "h= 32.7\n", - "The mass flow rate of air in kg/s is\n", - "mdot= 2.38761041673e-05\n", - "Therefore the constant surface heat flux qw in W/m**2 is\n", - "qw= 95.95\n", - "The tube surface temprature at the exit plane in °C is \n", - "Twe= 127.934250765\n" - ] - } - ], - "source": [ - " \n", - " \n", - " \n", - " \n", - " import math\n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 7, Example 9\"\n", - "#Air at one atmospheric pressure and temprature(Tbi=75°C) enters a tube of internal diameter(D)=4.0mm with average velocity(U)=2m/s\n", - "Tbi=75;\n", - "D=4*10**-3;#in metre\n", - "U=2;\n", - "#The tube length is L=1.0m and a constant heat flux is imposed by the tube surface on the air over the entire length.\n", - "L=1;\n", - "#An exit bulk mean temprature(Tbo)=125°C is required.\n", - "Tbo=125;\n", - "#The properties of air 100°C are density(rho=0.95kg/m**3),Prandtl number(Pr=0.70),conductivity(k=0.03W/(m*K)),viscosity(mu=2.18*10**-5kg/(m*s)),specific heat(cp=1.01kJ/(kg/K))\n", - "rho=0.95;\n", - "Pr=0.70;\n", - "k=0.03;\n", - "mu=2.18*10**-5;\n", - "cp=1.01*10**3;\n", - "#Re is reynolds number\n", - "print\"Reynold number is\"\n", - "Re=rho*U*D/mu\n", - "print\"Re=\",Re\n", - "#Leh is the hydrodynamic entrance length\n", - "print\"Therefore the flow is laminar.The hydrodynamic entrance length in m is\"\n", - "Leh=0.05*Re*D\n", - "print\"Leh=\",Leh\n", - "#Let is the thermal entrance length\n", - "print\"The thermal entrance length in m is\"\n", - "Let=0.05*Re*Pr*D\n", - "print\"Let=\",Let\n", - "#The length of tube is given as 1m.A reasonable approach is to consider the flow to be fully developed for both velocity and tempratures over the entire profile lengths.\n", - "#For a fully developed flow with constant surface heat flux,Nusselt number is Nu=4.36\n", - "Nu=4.36;\n", - "#h is the heat transfer coefficient\n", - "print\"The heat transfer coefficient in W/(m**2*K) is \"\n", - "h=Nu*(k/D)\n", - "print\"h=\",h\n", - "#Here h=hL Since the heat transfer coefficient is constant over the entire length of tube.\n", - "#hL is the local heat transfer coefficient\n", - "hL=h;\n", - "#from an energy balance qw*pi*D*L=mdot*cp*(Tbo-Tbi)\n", - "#mdot is mass flow rate\n", - "print\"The mass flow rate of air in kg/s is\"\n", - "mdot=rho*(math.pi/4)*D**2*U\n", - "print\"mdot=\",mdot\n", - "#qw is the constant surface heat flux\n", - "print\"Therefore the constant surface heat flux qw in W/m**2 is\"\n", - "qw=(mdot*cp*(Tbo-Tbi))/(math.pi*D*L)\n", - "print\"qw=\",qw\n", - "#Let Twe be the surface temprature at the exit plane.Then we can write hL*(Twe-Tbo)=qw\n", - "print\"The tube surface temprature at the exit plane in °C is \"\n", - "Twe=Tbo+(qw/hL)\n", - "print\"Twe=\",Twe\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex7.10:pg-338" - ] - }, - { - "cell_type": "code", - "execution_count": 10, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 7, Example 10\n", - "Reynold number is\n", - "Re= 348.623853211\n", - "Therefore the flow is laminar.The hydrodynamic entrance length in m is\n", - "Leh= 0.0697247706422\n", - "The thermal entrance length in m is\n", - "Let= 0.0488073394495\n", - "The thermal entrance length is greater than the tube length Therefore the flow is hydrodynamically developed but not thermally developed\n", - "The inverse of graetz number Gr_1 is\n", - "Gr_1= 0.040977443609\n", - "Therefore the local heat transfer coefficient in W/(m**2*K) is\n", - "hL= 35.25\n", - "The mass flow rate of air in kg/s is\n", - "mdot= 2.38761041673e-05\n", - "Therefore surafce heat flux qw in W/m**2 is\n", - "qw= 2398.75\n", - "The tube surface temprature at the exit plane in °C is \n", - "Twe= 193.04964539\n" - ] - } - ], - "source": [ - " \n", - " \n", - " \n", - " \n", - " import math\n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 7, Example 10\"\n", - "#Air at one atmospheric pressure and temprature(Tbi=75°C) enters a tube of internal diameter(D)=4.0mm with average velocity(U)=2m/s\n", - "Tbi=75;\n", - "D=4*10**-3;\n", - "U=2;\n", - "#The heated tube length is L=0.04m and a constant heat flux is imposed by the tube surface on the air over the entire length.\n", - "L=0.04;\n", - "#An exit bulk mean temprature(Tbo)=125°C is required.\n", - "Tbo=125;\n", - "#The properties of air 100°C are density(rho=0.95kg/m**3),Prandtl number(Pr=0.70),conductivity(k=0.03W/(m*K)),viscosity(mu=2.18*10**-5kg/(m*s)),specific heat(cp=1.01kJ/(kg/K))\n", - "rho=0.95;\n", - "Pr=0.70;\n", - "k=0.03;\n", - "mu=2.18*10**-5;\n", - "cp=1.01*10**3;\n", - "#Re is the reynolds number \n", - "print\"Reynold number is\"\n", - "Re=rho*U*D/mu\n", - "print\"Re=\",Re\n", - "#Leh is the hydrodynamic entrance length\n", - "print\"Therefore the flow is laminar.The hydrodynamic entrance length in m is\"\n", - "Leh=0.05*Re*D\n", - "print\"Leh=\",Leh\n", - "#Let is thermal entrance length\n", - "print\"The thermal entrance length in m is\"\n", - "Let=0.05*Re*Pr*D\n", - "print\"Let=\",Let\n", - "print\"The thermal entrance length is greater than the tube length Therefore the flow is hydrodynamically developed but not thermally developed\" \n", - "#We calculate the inverse graetz number at x=L=0.04m\n", - "x=0.04;\n", - "#Gr_1 is inverse of graetz number\n", - "print\"The inverse of graetz number Gr_1 is\"\n", - "Gr_1=(x/D)*(1/(Re*Pr))\n", - "print\"Gr_1=\",Gr_1\n", - "#For constant surface heat flux nusselt number is Nu=4.7 and Graetz number is Gr=4.1*10**-2\n", - "Nu=4.7;\n", - "Gr=4.1*10**-2;\n", - "#hL is the local heat transfer coefficient\n", - "print\"Therefore the local heat transfer coefficient in W/(m**2*K) is\"\n", - "hL=Nu*(k/D)\n", - "print\"hL=\",hL\n", - "#from an energy balance qw*pi*D*L=mdot*cp*(Tbo-Tbi)\n", - "#mdot is the mass flow rate\n", - "print\"The mass flow rate of air in kg/s is\"\n", - "mdot=rho*(math.pi/4)*D**2*U\n", - "print\"mdot=\",mdot\n", - "#qw is the surface heat flux\n", - "print\"Therefore surafce heat flux qw in W/m**2 is\"\n", - "qw=(mdot*cp*(Tbo-Tbi))/(math.pi*D*L)\n", - "print\"qw=\",qw\n", - "#Let Twe be the surface temprature at the exit plane.Then we can write hL*(Twe-Tbo)=qw\n", - "print\"The tube surface temprature at the exit plane in °C is \"\n", - "Twe=Tbo+(qw/hL)\n", - "print\"Twe=\",Twe\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex7.11:pg-339" - ] - }, - { - "cell_type": "code", - "execution_count": 6, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - " Introduction to heat transfer by S.K.Som, Chapter 7, Example 11\n", - "Reynold number is\n", - "Re1= 13541.3214942\n", - "Nusselt number is\n", - "Nubar1= 56.808608087\n", - "The heat transfer transfer coefficient in W/(m**2*°C) \n", - "hbar1= 522.6391944\n", - "Outlet fluid temprature in first iteration is Tbo2 in °C is\n", - "Tb2 in °C is\n", - "Tb2= -30.4912413164\n", - "Reynold number is\n", - "Re2= 13938.8493187\n", - "Nusselt number is\n", - "The heat transfer transfer coefficient in W/(m**2*°C) \n", - "hbar2= 784.03829067\n", - "Outlet fluid temprature in second iteration is Tbo3 in °C is\n", - "Tbo3= -16.646852652\n", - "Tb3 in °C is\n", - "The Exit fluid temprature after second iteration is obtained as Tbo=-16.67°C\n", - "Tb3= -28.323426326\n" - ] - } - ], - "source": [ - " \n", - " \n", - " \n", - " \n", - " import math\n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 7, Example 11\"\n", - "#Liquid sulphur di oxide in a saturated state flows inside a L=5m long tube and D=25mm internal diameter with a mass flow rate(mdot) of 0.15 kg/s.\n", - "#The tube is heated at a constant surface temprature(Tw) of -10°C and the inlet fluid temprature is Tbi=-40°C\n", - "Tw=-10;\n", - "Tbi=-40;\n", - "mdot=0.15;\n", - "D=0.025;#in metre\n", - "L=5;\n", - "#The properties to be used shoud be estimated at a temprature which is arithmetic mean of Tbi and Tbo.\n", - "#Since (outlet fluid temprature Tbo) is not known a priori,the solution has to be based on an iterative method starting with a guess value of Tb1=(Tbi+Tbo)/2\n", - "#Here we denote bulk mean temprature as Tb.The superscript refers to the no. of trials\n", - "#For first trial,guess Tbo1=-20°C;so Tb1=-30°C\n", - "#We have the property values as follows at a temprature of -30°C.\n", - "rhob1=1520.64;#density in kg/m**3\n", - "nub1=0.371*10**-6;#kinematic viscosity in m**2/s\n", - "kb1=0.23;#conductivity in W/(m*°C)\n", - "Prb1=3.31;#Prandtl number\n", - "mub1=nub1*rhob1;#viscosity in kg/(m*s)\n", - "cpb1=1361.6;#specific heat in J/(kg*K)\n", - "#muw=nuw*rhow at Tw=10°C\n", - "nuw=0.288*10**-6;#kinematic viscosity at Tw in m**2/s\n", - "rhow=1463.61;#density at Tw in kg/m**3\n", - "muw=nuw*rhow;#viscosity at Tw in kg/(m*s)\n", - "#The reynolds number is found as Re1=(4*mdot)/(math.pi*D*mub1)\n", - "print\"Reynold number is\"\n", - "Re1=(4*mdot)/(math.pi*D*mub1)\n", - "print\"Re1=\",Re1\n", - "#Hence the flow is turbulent\n", - "#Now using equation, nusselt number is,Nubar1=0.027*(Re1)**0.8*Prb1**(1/3)*(mub1/muw)**0.14\n", - "print\"Nusselt number is\"\n", - "Nubar1=0.027*(Re1)**0.8*Prb1**(1/3)*(mub1/muw)**0.14\n", - "print\"Nubar1=\",Nubar1\n", - "#The heat transfer transfer coefficient hbar1=(kb1/D)*Nubar1\n", - "print\"The heat transfer transfer coefficient in W/(m**2*°C) \"\n", - "hbar1=(kb1/D)*Nubar1\n", - "print\"hbar1=\",hbar1\n", - "#The outlet fluid temprature can be found by making use of eqn Tbo2=Tw-(Tw-Tbi)*math.e((-math.pi*D*L*hbar1)/(mdot*cpb1))\n", - "print\"Outlet fluid temprature in first iteration is Tbo2 in °C is\"\n", - "Tbo2=Tw-(Tw-Tbi)*math.e**((-math.pi*D*L*hbar1)/(mdot*cpb1))\n", - "#Tb2 is the bulk mean temprature.\n", - "print\"Tb2 in °C is\"\n", - "Tb2=(Tbi+Tbo2)/2\n", - "print\"Tb2=\",Tb2\n", - "#Since the value differs from the assumed value of Tb1=-30°C,WE require furtheriteration,Therfore we start second trial with Tb2=-28.36°C\n", - "#We have the property value at a temprature of -28.36°C as follows\n", - "rhob2=1514;#density in kg/m**3\n", - "nub2=0.362*10**-6;#kinematic viscosity in m**2/s\n", - "kb2=0.229;#conductivity in W/(m*°C)\n", - "Prb2=3.23;#Prandtl number\n", - "mub2=nub2*rhob2;#viscosity in kg/(m*s)\n", - "cpb2=1362;#specific heat in J/(kg*K)\n", - "#muw=nuw*rhow at Tw=10°C\n", - "nuw=0.288*10**-6;#viscosity at Tw in m**2/s\n", - "rhow=1463.61;#density at Tw in kg/m**3\n", - "muw=nuw*rhow;#kinematic viscosity at Tw in kg/(m*s)\n", - "#The reynolds number is found as Re2=(4*mdot)/(math.pi*D*mub2)\n", - "print\"Reynold number is\"\n", - "Re2=(4*mdot)/(math.pi*D*mub2)\n", - "print\"Re2=\",Re2\n", - "#Now using equation, nusselt number is,Nubar2=0.027*(Re2)**0.8*Prb2**(1/3.0)*(mub2/muw)**0.14\n", - "print\"Nusselt number is\"\n", - "Nubar2=0.027*(Re2)**0.8*Prb2**(1/3.0)*(mub2/muw)**0.14\n", - "#The heat transfer transfer coefficient hbar2=(kb2/D)*Nubar2\n", - "print\"The heat transfer transfer coefficient in W/(m**2*°C) \"\n", - "hbar2=(kb2/D)*Nubar2\n", - "print\"hbar2=\",hbar2\n", - "#The outlet fluid temprature can be found by making use of eqn Tbo3=Tw-(Tw-Tbi)*math.e((-math.pi*D*L*hbar2)/(mdot*cpb2))\n", - "print\"Outlet fluid temprature in second iteration is Tbo3 in °C is\"\n", - "Tbo3=Tw-(Tw-Tbi)*math.e**((-math.pi*D*L*hbar2)/(mdot*cpb2))\n", - "print\"Tbo3=\",Tbo3\n", - "#Tb3 is the bulk mean temprature.\n", - "print\"Tb3 in °C is\"\n", - "Tb3=(Tbi+Tbo3)/2\n", - "#We see that difference between Tbo2 and Tbo3 and that between Tb2 and Tb3 is marginal.Therfore we can stop iteration and present the result as Tbo=-16.67°C\n", - "print\"The Exit fluid temprature after second iteration is obtained as Tbo=-16.67°C\"\n", - "print\"Tb3=\",Tb3" - ] - } - ], - "metadata": { - "kernelspec": { - "display_name": "Python 2", - "language": "python", - "name": "python2" - }, - "language_info": { - "codemirror_mode": { - "name": "ipython", - "version": 2 - }, - "file_extension": ".py", - "mimetype": "text/x-python", - "name": "python", - "nbconvert_exporter": "python", - "pygments_lexer": "ipython2", - "version": "2.7.11" - } - }, - "nbformat": 4, - "nbformat_minor": 0 -} diff --git a/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter8.ipynb b/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter8.ipynb index 882c8bf9..a6c237e4 100644 --- a/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter8.ipynb +++ b/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter8.ipynb @@ -79,7 +79,20 @@ "#The rate of heat transfer is given by q=hbarL*A*(Tw-Tinf)\n", "print\"The rate of heat transfer in W is\"\n", "q=hbarL*A*(Tw-Tinf)\n", - "print\"q=\",q" + "print\"q=\",q\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n" ] }, { @@ -115,6 +128,7 @@ } ], "source": [ + " \n", "import math \n", " \n", "print\"Introduction to heat transfer by S.K.Som, Chapter 8, Example 2\"\n", @@ -151,7 +165,24 @@ "#spac is the minimum spacing \n", "print\"The minimum spacing in metre is\"\n", "spac=2*delta\n", - "print\"spac=\",spac" + "print\"spac=\",spac\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n" ] }, { @@ -188,6 +219,7 @@ } ], "source": [ + "\n", "from scipy.integrate import quad\n", "print \"Introduction to heat transfer by S.K.Som, Chapter 8, Example 3\"\n", "#Considering question 5.7\n", @@ -243,7 +275,14 @@ "print \"Mass flow rate at x=0.8m,in kG is\"\n", "I=quad(lambda y:465.9*(y-116*y*2+3341*y*3),0,delta)\n", "mdot=rho*B*I[0]\n", - "print\"mdot=\",mdot" + "print\"mdot=\",mdot\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n" ] }, { @@ -275,6 +314,7 @@ } ], "source": [ + " \n", "import math \n", " \n", "print\"Introduction to heat transfer by S.K.Som, Chapter 8, Example 4\"\n", @@ -312,7 +352,33 @@ "hL=(2*k)/delta;\n", "hbarL=(4.0/3)*(hL)#NOTE:The answer in the book is incorrect(calculation mistake)\n", "print\"hL=\",hL\n", - "print\"hbarL=\",hbarL" + "print\"hbarL=\",hbarL\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n" ] }, { @@ -366,6 +432,7 @@ } ], "source": [ + " \n", "import math \n", " \n", "print\"Introduction to heat transfer by S.K.Som, Chapter 8, Example 5\"\n", @@ -442,7 +509,51 @@ "print hbarL\n", "print\"The rate of heat transfer in W is \"\n", "Q=hbarL*A*(Tw-Tinf)\n", - "print Q" + "print Q\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n" ] }, { @@ -488,6 +599,10 @@ } ], "source": [ + " \n", + " \n", + " \n", + " \n", "import math \n", " \n", "print\"Introduction to heat transfer by S.K.Som, Chapter 8, Example 6\"\n", @@ -548,7 +663,16 @@ "#The current flowing in the wire I=(q/(R*L)**(1/2.0)\n", "print\"The current flowing in the wire in Ampere is\"\n", "I=(q/(R*L))**(1/2.0)\n", - "print\"I=\",I" + "print\"I=\",I\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n" ] }, { @@ -585,6 +709,7 @@ } ], "source": [ + " \n", "import math \n", " \n", "print\"Introduction to heat transfer by S.K.Som, Chapter 8, Example 7\"\n", @@ -625,7 +750,26 @@ "#The heat loss per meter length is given by q=hbar*A*(Tw-Tinf)\n", "print\"The heat loss per meter length in W is\"\n", "q=hbar*A*(Tw-Tinf)\n", - "print\"q=\",q" + "print\"q=\",q\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n" ] }, { @@ -664,6 +808,7 @@ } ], "source": [ + " \n", "import math \n", " \n", "print\"Introduction to heat transfer by S.K.Som, Chapter 8, Example 8\"\n", @@ -709,7 +854,18 @@ "print\"Hence,steady state Surface temprature in °C is\"\n", "Tw=Tinf+(P/(hbarD*math.pi*D*L))\n", "print\"Hence we see that our guess is in excellent agreement with the calculated value\"\n", - "print\"Tw=\",Tw" + "print\"Tw=\",Tw\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n" ] } ], diff --git a/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter8_vyeGLD8.ipynb b/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter8_vyeGLD8.ipynb deleted file mode 100644 index a6c237e4..00000000 --- a/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter8_vyeGLD8.ipynb +++ /dev/null @@ -1,893 +0,0 @@ -{ - "cells": [ - { - "cell_type": "markdown", - "metadata": { - "collapsed": true - }, - "source": [ - "# Chapter 08:Principles of free convection" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex8.1:pg-355" - ] - }, - { - "cell_type": "code", - "execution_count": 1, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 8, Example 1\n", - "Grashoff number is\n", - "GrL= 2175146201.53\n", - "Rayleigh number is\n", - "RaL= 9440134514.65\n", - "Therefore the flow is turbulent\n", - "Now we use [(hbarL*L)/k]=0.10*(GrL*Pr)**(1/3)\n", - "The average heat transfer coefficient in W/(m**2*K) is\n", - "hbarL= 0.314\n", - "The rate of heat transfer in W is\n", - "q= 0.5024\n" - ] - } - ], - "source": [ - "import math \n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 8, Example 1\"\n", - "#Water is heated by a vertical flat plate length(L=200mm or .2m )by breadth(B=200mm) which is maintained at temprature,Tw=60°C\n", - "Tw=60;\n", - "L=.2;\n", - "B=.2;# in metre\n", - "#Area(A) is L*B \n", - "A=L*B;\n", - "#Water is at temprature,Tinf=20°C\n", - "Tinf=20;\n", - "#At mean film temprature 40°C The physical properties parameters can be taken as \n", - "#conductivity(k=0.0628W/(m*K)),Prandtl number(Pr=4.34),density(rho=994.59kg/m**3),kinematic viscosity(nu=0.658*10**-6m**2/s),volume expnasion coefficient(Beta=3*10**-4K**-1))\n", - "k=0.628;\n", - "Pr=4.34;\n", - "rho=994.59;\n", - "nu=0.658*10**-6;\n", - "Beta=3*10**-4;\n", - "#g is acceleration due to gravity =9.81m/s**2\n", - "g=9.81;\n", - "#Grashoff number is given by GrL=(g*beta*(Tw-Tinf)*L**3)/(nu)**2\n", - "print\"Grashoff number is\"\n", - "GrL=(g*Beta*(Tw-Tinf)*L**3)/(nu)**2\n", - "print\"GrL=\",GrL\n", - "#Rayleigh number is defined as RaL=GrL*Pr\n", - "print\"Rayleigh number is\"\n", - "RaL=GrL*Pr\n", - "print\"RaL=\",RaL\n", - "print\"Therefore the flow is turbulent\"\n", - "print\"Now we use [(hbarL*L)/k]=0.10*(GrL*Pr)**(1/3)\"\n", - "#hbarL is the average heat transfer coefficient\n", - "print\"The average heat transfer coefficient in W/(m**2*K) is\"\n", - "hbarL=(0.10*(GrL*Pr)**(1/3)*k)/L\n", - "print\"hbarL=\",hbarL\n", - "#The rate of heat transfer is given by q=hbarL*A*(Tw-Tinf)\n", - "print\"The rate of heat transfer in W is\"\n", - "q=hbarL*A*(Tw-Tinf)\n", - "print\"q=\",q\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex8.2:pg-357" - ] - }, - { - "cell_type": "code", - "execution_count": 2, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 8, Example 2\n", - "The minimum spacing between the plates will be twice the thickness of the boundary layer at the trailing edge where x=0.09\n", - "Grashoff number is\n", - "GrL= 198210197.615\n", - "Rayleigh number is\n", - "RaL= 860232257.647\n", - "Since Ra<10**9,Therefore the flow is laminar\n", - "The thickness of the boundary layer in metre is\n", - "delta= 4.11168026839e-10\n", - "The minimum spacing in metre is\n", - "spac= 8.22336053678e-10\n" - ] - } - ], - "source": [ - " \n", - "import math \n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 8, Example 2\"\n", - "#The thin plates are kept at temprature(Tw)=60°C while the temprature of water bath(Tinf)=20°C\n", - "Tw=60;\n", - "Tinf=20;\n", - "#The plates have length(L)=90mm or .09m\n", - "L=.09;\n", - "#The minimum spacing between the plates will be twice the thickness of the boundary layer at the trailing edge where x=0.09.\n", - "print\"The minimum spacing between the plates will be twice the thickness of the boundary layer at the trailing edge where x=0.09\"\n", - "x=.09;\n", - "#At mean film temprature 40°C The physical properties parameters can be taken as\n", - "# conducivity(k=0.0628W/(m*K)),Prandtl number(Pr=4.34),Density(rho=994.59kg/m**3),kinematic viscosity(nu=0.658*10**-6m**2/s),Volume expansion coefficient(Beta=3*10**-4K**-1)\n", - "k=0.628;\n", - "Pr=4.34;\n", - "rho=994.59;\n", - "nu=0.658*10**-6;\n", - "Beta=3*10**-4;\n", - "#g is acceleration due to gravity =9.81m/s**2\n", - "g=9.81;\n", - "#Grashoff number is given by GrL=(g*beta*(Tw-Tinf)*L**3)/(nu)**2\n", - "print\"Grashoff number is\"\n", - "GrL=(g*Beta*(Tw-Tinf)*L**3)/(nu)**2\n", - "print\"GrL=\",GrL\n", - "#Rayleigh number is defined as RaL=GrL*Pr\n", - "print\"Rayleigh number is\"\n", - "RaL=GrL*Pr\n", - "print\"RaL=\",RaL\n", - "print\"Since Ra<10**9,Therefore the flow is laminar\"\n", - "#delta is the thickness of the boundary layer\n", - "print\"The thickness of the boundary layer in metre is\"\n", - "delta=x*3.93*Pr**(-1/2)*(0.952+Pr)**(1/4)*GrL**(-1/4)\n", - "print\"delta=\",delta\n", - "#spac is the minimum spacing \n", - "print\"The minimum spacing in metre is\"\n", - "spac=2*delta\n", - "print\"spac=\",spac\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex8.3:pg-366" - ] - }, - { - "cell_type": "code", - "execution_count": 3, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 8, Example 3\n", - "Grashoff number is\n", - "Grx= 517025.52213\n", - "The boundary layer thickness in metre is\n", - "delta= 60304.3038858\n", - "The velocity at point x is ux in m/s is\n", - "ux= 3247798354.51\n", - "For maximum value of velocity,u\n", - "Maximum velocity in m/s is\n", - "Umax= 3.57089835848\n", - "Mass flow rate at x=0.8m,in kG is\n", - "mdot= 2.36830073295e+16\n" - ] - } - ], - "source": [ - "\n", - "from scipy.integrate import quad\n", - "print \"Introduction to heat transfer by S.K.Som, Chapter 8, Example 3\"\n", - "#Considering question 5.7\n", - "#A wall is exposed to nitrogen at one atmospheric pressure and temprature,Tinf=4°C.\n", - "Tinf=4.0;\n", - "#The wall is H=2.0m high and 2.5m wide and is maintained at temprature,Tw=56°C\n", - "Tw=56.0;\n", - "H=2.0;\n", - "B=2.5;\n", - "A=H*B;#Area of wall in m**2\n", - "#The properties of nitrogen at mean film temprature (56+4)/2=30°C are given as \n", - "#density(rho=1.142kg/m*3) ,conductivity(k=0.026W/(m*K)),kinematic viscosity(nu=15.630*10-6 m*2/s) ,prandtl number(Pr=0.713)\n", - "rho=1.142;\n", - "k=0.026;\n", - "nu=15.630*10**-6;\n", - "Pr=0.713;\n", - "Tf=30.0;#mean film temprature\n", - "Beta=1/(273.0+Tf);#volume expansion coefficient:unit K**-1\n", - "#Now Grashoff number is Grx=(g*Beta*(Tw-Tinf)*x*3)/nu*2\n", - "g=9.81;#acceleration due to gravity\n", - "print \"Grashoff number is\"\n", - "x=0.8;#distance from the bottom of wall\n", - "Grx=(g*Beta*(Tw-Tinf)*x*3)/nu*2\n", - "print\"Grx=\",Grx\n", - "#Using equation delta=x*Pr*(-0.5)(0.952+Pr)*(0.25)*Grx*(-0.25)\n", - "#delta is the boundary layer thickness\n", - "print \"The boundary layer thickness in metre is\"\n", - "delta=x*3.93*Pr*(-0.5)*(0.952+Pr)*(0.25)*Grx*(-0.25)\n", - "print\"delta=\",delta\n", - "#Now using equation ux=(g*Beta*delta*2(Tw-Tinf))/(4*nu)\n", - "#ux is the velocity at point x\n", - "print \"The velocity at point x is ux in m/s is\"\n", - "ux=(g*Beta*delta*2*(Tw-Tinf))/(4*nu)\n", - "print\"ux=\",ux\n", - "# (u/ux)=(y/delta)*(1-y/delta)**2\n", - "#Putting value of ux we get velovity function,u=465.9*(y-116*y*2+3341*y*3)\n", - "#For maximum value of u,du/dy=465.9*(1-232*y+10023*y**2)=0...this is a quadratic equation in which coefficients a=10023,b=232,c=1\n", - "a=10023;\n", - "b=232;\n", - "c=1;\n", - "#Solution for quadratic equation is given by y=(-b+-(b*2-4ac)*0.5)/2*a\n", - "print \"For maximum value of velocity,u\"\n", - "y=(b+(b*2-4*a*c)*0.5)/(2*a)#root of the quadratic equation\n", - "y=(b-(b*2-4*a*c)*0.5)/(2*a)#root of the quadratic equation\n", - "#The value of 0.0173 is at the edge of boundary layer,where u=0\n", - "#Therefore the maximum value occurs at y=0.00573m i.e Umax=465.9*y*(1-57.8*y)**2\n", - "y=0.00573;\n", - "#Umax is maximum velocity\n", - "print \"Maximum velocity in m/s is\"\n", - "Umax=465.9*y*(1-57.8*y)*2#NOTE:The answer given in the book is incorrect,in this expresssion they considered square on y only,however it is on whole expression (1-57.8*y)*2\n", - "#mdot is mass flow rate\n", - "print\"Umax=\",Umax\n", - "print \"Mass flow rate at x=0.8m,in kG is\"\n", - "I=quad(lambda y:465.9*(y-116*y*2+3341*y*3),0,delta)\n", - "mdot=rho*B*I[0]\n", - "print\"mdot=\",mdot\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex8.4:pg-369" - ] - }, - { - "cell_type": "code", - "execution_count": 11, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 8, Example 4\n", - "Grashoff number is\n", - "Rayleigh number is\n", - "Hence,the flow is laminar\n", - "The thickness of the boundary layer in metre is\n", - "The average heat transfer coeficient in W/(m**2*K) is\n", - "0.101781170483\n" - ] - } - ], - "source": [ - " \n", - "import math \n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 8, Example 4\"\n", - "#A square plate length,L=0.2m by breadth,B=0.2m is suspended vertically in a quiescent atmospheric air at a temprature(Tinf)=300K\n", - "L=0.2;\n", - "B=0.2;\n", - "Tinf=300;\n", - "#The Temprature of plate(Tw) is maintained at 400K\n", - "Tw=400;\n", - "#The required property value of air at a film temprature(Tf)=350K,kinematic viscosity (nu=20.75*10**-6),Prandtl number(Pr=0.69),conductivity(k=0.03W/(m*K))\n", - "Tf=350;\n", - "nu=20.75*10**-6;\n", - "Pr=0.69;\n", - "k=0.03;\n", - "#volume expansion coefficient is Beta\n", - "Beta=(1/Tf);\n", - "#g is acceleration due to gravity =9.81m/s**2\n", - "g=9.81;\n", - "#Grashoff number is given by GrL=(g*beta*(Tw-Tinf)*L**3)/(nu)**2\n", - "print\"Grashoff number is\"\n", - "GrL=(g*Beta*(Tw-Tinf)*L**3)/(nu)**2 \n", - "print\"GrL=\",GrL\n", - "#Rayleigh number is defined as RaL=GrL*Pr\n", - "print\"Rayleigh number is\"\n", - "RaL=GrL*Pr\n", - "print\"Hence,the flow is laminar\"\n", - "print\"RaL=\",RaL\n", - "#delta is the thickness of the boundary layer\n", - "print\"The thickness of the boundary layer in metre is\"\n", - "x=0.2;#location of trailing edge of plate\n", - "delta=(x*3.93*(0.952+Pr)**(1/4))/(Pr**(1/2)*(GrL)**(1/4))#NOTE:The answer in the book is incorrect(calculation mistake)\n", - "print\"delta=\",delta\n", - "#hL and hbarL are local and average heat transfer coefficient respectively\n", - "print\"The average heat transfer coeficient in W/(m**2*K) is\"\n", - "hL=(2*k)/delta;\n", - "hbarL=(4.0/3)*(hL)#NOTE:The answer in the book is incorrect(calculation mistake)\n", - "print\"hL=\",hL\n", - "print\"hbarL=\",hbarL\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex8.5:pg-373" - ] - }, - { - "cell_type": "code", - "execution_count": 4, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 8, Example 5\n", - "Grashoff number is\n", - "503958851.066\n", - "Rayleigh number is\n", - "357810784.257\n", - "Therefore the flow is laminar\n", - "Nusselt number is\n", - "75.3134665126\n", - "Average heat transfer coefficient(hbarL)in W/(m**2*°C)\n", - "The rate of heat transfer in W is \n", - "Now if we use NuL2=0.59*RaL**(1/4) with the value of C=0.59,n=(1/4)\n", - "Nusselt number is\n", - "Average heat transfer coefficient(hbarL)in W/(m**2*°C)\n", - "The rate of heat transfer in W is \n", - "49.9857347505\n", - "(b)For the horizontal plate facing up\n", - "Now RaL2=Gr*Pr*(Lc/L)**3\n", - "Rayleigh number is\n", - "Nusselt number is given by NuL3=C*(GrL*Pr)**n\n", - "Average heat transfer coefficient(hbarL)in W/(m**2*°C)\n", - "The rate of heat transfer in W is \n", - "64.6997833306\n", - "(c)When the hot surface faces is down\n", - "Nusselt number is given by NuL4=0.27*RaL2**(1/4)\n", - "13.1290144745\n", - "Average heat transfer coefficient(hbarL) in W/(m**2)\n", - "2.9408992423\n", - "The rate of heat transfer in W is \n", - "32.3498916653\n" - ] - } - ], - "source": [ - " \n", - "import math \n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 8, Example 5\"\n", - "#A square plate of length(L)=0.5m by breadth,B=0.5m in a room at temprature,Tinf=30°C\n", - "#One side of plate is kept a uniform temprature(Tw)=74°C\n", - "Tw=74;\n", - "L=0.5;\n", - "B=0.5;\n", - "Tinf=30.0;\n", - "#The required properties at the film temprature(Tf)=52°C are kinematic viscosity(nu=1.815*10**-5),Prandtl number(Pr=0.71),conductivity(k=0.028W/(m*°C))\n", - "Tf=52.0;\n", - "Pr=0.71;\n", - "nu=1.815*10**-5;\n", - "k=0.028;\n", - "#Area(A)=L*B m**2\n", - "A=L*B;\n", - "#Volume expansion coefficient is Beta\n", - "Beta=1/(273+Tf);\n", - "#g is acceleration due to gravity =9.81m/s**2\n", - "g=9.81;\n", - "#Grashoff number is given by GrL=(g*beta*(Tw-Tinf)*L**3)/(nu)**2\n", - "print\"Grashoff number is\"\n", - "GrL=(g*Beta*(Tw-Tinf)*L**3)/(nu)**2 \n", - "print GrL\n", - "#Rayleigh number is defined as RaL1=GrL*Pr\n", - "print\"Rayleigh number is\"\n", - "RaL1=GrL*Pr\n", - "print RaL1\n", - "print\"Therefore the flow is laminar\"\n", - "#We make use of following equation to find Nusselt number,NuL1=(4/3)*(0.508*Pr**(-1/2)*(0.952+Pr)**(-1/4)*Gr**(1/4))\n", - "print\"Nusselt number is\"\n", - "NuL1=(4.0/3)*(0.508*Pr**(1.0/2)*(0.952+Pr)**(-1.0/4)*GrL**(1.0/4))\n", - "#Average heat transfer coefficient(hbarL) is given by (NuL*k)/L\n", - "print NuL1\n", - "print\"Average heat transfer coefficient(hbarL)in W/(m**2*°C)\"\n", - "hbarL=(NuL1*k)/L\n", - "#The rate of heat transfer(Q) from the plate by free convection is given by Q=hbarL*A*(Tw-Tinf)\n", - "print\"The rate of heat transfer in W is \"\n", - "Q=hbarL*A*(Tw-Tinf)\n", - "print\"Now if we use NuL2=0.59*RaL**(1/4) with the value of C=0.59,n=(1/4)\"\n", - "print\"Nusselt number is\"\n", - "NuL2=0.59*RaL1**(1.0/4)\n", - "#Average heat transfer coefficient(hbarL) is given by (NuL*k)/L\n", - "print\"Average heat transfer coefficient(hbarL)in W/(m**2*°C)\"\n", - "hbarL=(NuL2*k)/L\n", - "#The rate of heat transfer(Q) from the plate by free convection is given by Q=hbarL*A*(Tw-Tinf)\n", - "print\"The rate of heat transfer in W is \"\n", - "Q=hbarL*A*(Tw-Tinf)\n", - "print Q\n", - "print\"(b)For the horizontal plate facing up\"\n", - "#Perimeter(P) for a square plate is P=4*L\n", - "P=4*L;\n", - "#Characterstic length(Lc)=A/P\n", - "Lc=A/P\n", - "print\"Now RaL2=Gr*Pr*(Lc/L)**3\"\n", - "print\"Rayleigh number is\"\n", - "RaL2=GrL*Pr*(Lc/L)**3\n", - "#The values of constants,C=0.54 and n=(1/4)\n", - "C=0.54;\n", - "n=(1.0/4);\n", - "print\"Nusselt number is given by NuL3=C*(GrL*Pr)**n\"\n", - "NuL3=C*(RaL2)**n\n", - "print\"Average heat transfer coefficient(hbarL)in W/(m**2*°C)\"\n", - "hbarL=(NuL3*k)/Lc\n", - "print\"The rate of heat transfer in W is \"\n", - "Q=hbarL*A*(Tw-Tinf)\n", - "print Q\n", - "print\"(c)When the hot surface faces is down\"\n", - "print\"Nusselt number is given by NuL4=0.27*RaL2**(1/4)\"\n", - "NuL4=0.27*RaL2**(1.0/4)\n", - "print NuL4\n", - "print\"Average heat transfer coefficient(hbarL) in W/(m**2)\"\n", - "hbarL=(NuL4*k)/Lc\n", - "print hbarL\n", - "print\"The rate of heat transfer in W is \"\n", - "Q=hbarL*A*(Tw-Tinf)\n", - "print Q\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex8.6:pg-375" - ] - }, - { - "cell_type": "code", - "execution_count": 5, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 8, Example 6\n", - "Grashoff number is\n", - "GrL= 813719594.384\n", - "Rayleigh number is\n", - "RaL= 569603716.069\n", - "Therefore the flow is laminar\n", - "Now we use NuL=0.59*RaL**(1/4.0) with the value of constants C=0.59,n=(1/4.0)\n", - "Nusselt number is\n", - "NuL= 91.1475952489\n", - "Average heat transfer coefficient in W/(m**2*K)\n", - "hbarL1= 5.46885571493\n", - "Grashoff number GrD=GrL*(D/L)**3\n", - "GrD= 0.00650975675508\n", - "The correction factor is\n", - "F= 39.485281111\n", - "The correct value of Average heat transfer coefficient(hbarL2)=hbarL1*F in W/(m**2*K) is\n", - "hbarL2= 215.939305259\n", - "The ohmic loss in W is \n", - "q= 3.39196667512\n", - "The current flowing in the wire in Ampere is\n", - "I= 7.51882822777\n" - ] - } - ], - "source": [ - " \n", - " \n", - " \n", - " \n", - "import math \n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 8, Example 6\"\n", - "#A vertical wire of length(L)=0.5m and Dimeter(D)=0.1mm is maintained at temprature, Tw=400K\n", - "#The temprature of quicsent air is Tinf=300K\n", - "#Resistance(R) per meter length is 0.12ohm\n", - "R=0.12;\n", - "Tw=400.0;\n", - "L=0.5;\n", - "D=0.1*10**-3;#in metre\n", - "Tinf=300;\n", - "#The required properties at the film temprature(Tf)=350K are kinematic viscosity(nu=20.75*10**-6m**2/s),Prandtl number(Pr=0.70),conductivity(k=0.03W/(m*°C))\n", - "Tf=350.0;\n", - "Pr=0.70;\n", - "nu=20.75*10**-6;\n", - "k=0.03;\n", - "#Area(A)=L*B m**2\n", - "A=math.pi*D*L;\n", - "#Volume expansion Coefficient is Beta\n", - "Beta=1/(Tf);\n", - "#g is acceleration due to gravity =9.81m/s**2\n", - "g=9.81;\n", - "#Grashoff number is given by GrL=(g*beta*(Tw-Tinf)*L**3)/(nu)**2\n", - "print\"Grashoff number is\"\n", - "GrL=(g*Beta*(Tw-Tinf)*L**3)/(nu)**2 \n", - "print\"GrL=\",GrL\n", - "#Rayleigh number is defined as RaL=GrL*Pr\n", - "print\"Rayleigh number is\"\n", - "RaL=GrL*Pr\n", - "print\"RaL=\",RaL\n", - "print\"Therefore the flow is laminar\"\n", - "#NuL is nusselt number\n", - "#C and n are constants\n", - "print\"Now we use NuL=0.59*RaL**(1/4.0) with the value of constants C=0.59,n=(1/4.0)\"\n", - "print\"Nusselt number is\"\n", - "NuL=0.59*RaL**(1/4.0)\n", - "print\"NuL=\",NuL\n", - "#hbarL1 is the Average heat transfer coefficient\n", - "print\"Average heat transfer coefficient in W/(m**2*K)\"\n", - "hbarL1=(NuL*k)/L\n", - "print\"hbarL1=\",hbarL1\n", - "#Grashoff number GrD=GrL*(D/L)**3\n", - "print\"Grashoff number GrD=GrL*(D/L)**3\"\n", - "GrD=GrL*(D/L)**3\n", - "print\"GrD=\",GrD\n", - "#The correction factor is given By F=1.3*((L/D)/GrD)**(1/4.0)+1.0\n", - "print\"The correction factor is\"\n", - "F=1.3*((L/D)/GrD)**(1/4.0)+1.0\n", - "print\"F=\",F\n", - "print\"The correct value of Average heat transfer coefficient(hbarL2)=hbarL1*F in W/(m**2*K) is\"\n", - "hbarL2=hbarL1*F\n", - "print\"hbarL2=\",hbarL2\n", - "#The ohmic power loss is given by energy balance I**2*R=q=hbar2*A*(Tw-Tinf)\n", - "#q is the ohmic power loss\n", - "print\"The ohmic loss in W is \"\n", - "q=hbarL2*A*(Tw-Tinf)\n", - "print\"q=\",q\n", - "#The current flowing in the wire I=(q/(R*L)**(1/2.0)\n", - "print\"The current flowing in the wire in Ampere is\"\n", - "I=(q/(R*L))**(1/2.0)\n", - "print\"I=\",I\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex8.7:pg-378" - ] - }, - { - "cell_type": "code", - "execution_count": 6, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 8, Example 7\n", - "Grashoff number is\n", - "GrD= 53311595.6796\n", - "Rayleigh number is\n", - "RaD= 37318116.9757\n", - "The flow is laminar over the entire cylinder\n", - "we use following equation to find Nusselt number NuD=(0.60+((0.387*RaD**(1/6))/(1+(0.559/Pr**(9/16)))**(8/27)))**2\n", - "NuD= 0.974169\n", - "Average heat transfer coefficient in W/(m**2*K)\n", - "hbar= 0.14612535\n", - "The heat loss per meter length in W is\n", - "q= 9.64039284733\n" - ] - } - ], - "source": [ - " \n", - "import math \n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 8, Example 7\"\n", - "#A long horizontal pressurized hot water of diameter(D)=200mm passes through a room where the air temprature is Tinf=25°C\n", - "D=.2;\n", - "Tinf=25;\n", - "#Length(L)=1m ,since the unit length is considered\n", - "L=1;\n", - "#Area(A)=pi*L*D\n", - "A=math.pi*L*D;\n", - "#The pipe surface temprature is Tw=130°C\n", - "Tw=130;\n", - "#The properties of air at the film temprature Tf=77.5°C are kinematic viscosity(nu=21*10**-6m**2/s),Prandtl number(Pr=0.70),Conductivity(k=0.03W/(m*K))\n", - "Tf=77.5;\n", - "nu=21*10**-6;\n", - "k=0.03;\n", - "Beta=(1/(273+Tf));#Volume expansion coefficient in k**-1)\n", - "Pr=0.70;\n", - "#g is acceleration due to gravity =9.81m/s**2\n", - "g=9.81;\n", - "#Grashoff number is given by GrD=(g*beta*(Tw-Tinf)*L**3)/(nu)**2\n", - "print\"Grashoff number is\"\n", - "GrD=(g*Beta*(Tw-Tinf)*D**3)/(nu)**2 \n", - "print\"GrD=\",GrD\n", - "#Rayleigh number is defined as RaD=GrD*Pr\n", - "print\"Rayleigh number is\"\n", - "RaD=GrD*Pr\n", - "print\"RaD=\",RaD\n", - "print\"The flow is laminar over the entire cylinder\"\n", - "#NuD is the nusselt number\n", - "print\"we use following equation to find Nusselt number NuD=(0.60+((0.387*RaD**(1/6))/(1+(0.559/Pr**(9/16)))**(8/27)))**2\"\n", - "NuD=(0.60+((0.387*RaD**(1/6))/(1+(0.559/Pr**(9/16)))**(8/27)))**2\n", - "print\"NuD=\",NuD\n", - "#hbar is the avearge heat transfer coefficient\n", - "print\"Average heat transfer coefficient in W/(m**2*K)\"\n", - "hbar=(NuD*k)/D\n", - "print\"hbar=\",hbar\n", - "#The heat loss per meter length is given by q=hbar*A*(Tw-Tinf)\n", - "print\"The heat loss per meter length in W is\"\n", - "q=hbar*A*(Tw-Tinf)\n", - "print\"q=\",q\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex8.8:pg-381" - ] - }, - { - "cell_type": "code", - "execution_count": 7, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 8, Example 8\n", - "Let us take first trial Tw=64°C\n", - "Grashoff number is\n", - "GrD= 226303.67232\n", - "Rayleigh number is\n", - "The flow is laminar \n", - "RaD= 941423.276851\n", - "we use following equation to find Nusselt number NuD=(0.60+((0.387*RaD**(1/6))/(1+(0.559/Pr**(9/16)))**(8/27)))**2\n", - "NuD= 0.974169\n", - "Average heat transfer coefficient in W/(m**2*K)\n", - "hbarD= 77.20289325\n", - "Hence,steady state Surface temprature in °C is\n", - "Hence we see that our guess is in excellent agreement with the calculated value\n", - "Tw= 793.068225127\n" - ] - } - ], - "source": [ - " \n", - "import math \n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 8, Example 8\"\n", - "#An electric immersion heater diameter(D)=8mm and length(L)=300mm is rated at power input,P=450W\n", - "P=450;\n", - "L=0.3;#in metre\n", - "D=0.008;#in metre\n", - "#If the heater is horizontally positioned in a large tank of stationery water at temprature,Tinf=20°C\n", - "Tinf=20;\n", - "#At steady state ,The electrical power input(P)=(Q)Heat loss from the heater\n", - "#P=Q\n", - "#Q=hbarD*(pi*D)*L*(Tw-Tinf)\n", - "#This gives Tw(surface temprature)=Tinf+(P/(hbarD*pi*D*L))\n", - "#So we need to find Average heat transfer coefficient,hbarD.\n", - "#In this problem we need to take guess of steady state surface temprature(Tw) and iterate the solution for Tw till a desired convergence is achieved.\n", - "print\"Let us take first trial Tw=64°C\"\n", - "Tw=64;\n", - "Tf=(Tw+Tinf)/2;#mean film temprature\n", - "#At this temprature of 42°C,The required properties of water kinematic viscosity(nu=6.25*10**-7m**2/s),Prandtl number(Pr=4.16),Conductivity(k=0.634W/(m*K)),Beta=4*10**-4K**-1\n", - "Beta=4*10**-4;#Volume expansion coefficient\n", - "nu=6.25*10**-7;\n", - "Pr=4.16;\n", - "k=0.634;\n", - "#g is acceleration due to gravity =9.81m/s**2\n", - "g=9.81;\n", - "#Grashoff number is given by GrD=(g*beta*(Tw-Tinf)*L**3)/(nu)**2\n", - "print\"Grashoff number is\"\n", - "GrD=(g*Beta*(Tw-Tinf)*D**3)/(nu)**2 \n", - "print\"GrD=\",GrD\n", - "#Rayleigh number is defined as RaD=GrD*Pr\n", - "print\"Rayleigh number is\"\n", - "RaD=GrD*Pr\n", - "print\"The flow is laminar \"\n", - "print\"RaD=\",RaD\n", - "#/NuD is nusselt number\n", - "#hbarD is Average heat transfer coefficient\n", - "print\"we use following equation to find Nusselt number NuD=(0.60+((0.387*RaD**(1/6))/(1+(0.559/Pr**(9/16)))**(8/27)))**2\"\n", - "NuD=(0.60+((0.387*RaD**(1/6))/(1+(0.559/Pr**(9/16)))**(8/27)))**2\n", - "print\"NuD=\",NuD\n", - "print\"Average heat transfer coefficient in W/(m**2*K)\"\n", - "hbarD=(NuD*k)/D\n", - "print\"hbarD=\",hbarD\n", - "print\"Hence,steady state Surface temprature in °C is\"\n", - "Tw=Tinf+(P/(hbarD*math.pi*D*L))\n", - "print\"Hence we see that our guess is in excellent agreement with the calculated value\"\n", - "print\"Tw=\",Tw\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n" - ] - } - ], - "metadata": { - "kernelspec": { - "display_name": "Python 2", - "language": "python", - "name": "python2" - }, - "language_info": { - "codemirror_mode": { - "name": "ipython", - "version": 2 - }, - "file_extension": ".py", - "mimetype": "text/x-python", - "name": "python", - "nbconvert_exporter": "python", - "pygments_lexer": "ipython2", - "version": "2.7.11" - } - }, - "nbformat": 4, - "nbformat_minor": 0 -} diff --git a/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter9.ipynb b/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter9.ipynb index 2944362a..7d76afa3 100644 --- a/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter9.ipynb +++ b/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter9.ipynb @@ -46,6 +46,10 @@ } ], "source": [ + " \n", + " \n", + " \n", + " \n", "import math\n", " \n", "print\"Introduction to heat transfer by S.K.Som, Chapter 9, Example 1\"\n", @@ -86,7 +90,18 @@ "print\"Reynolds no. is\"\n", "ReL=(4*mdotc)/(mu)\n", "print\"Therefore the flow is laminar and hence the use of the equation is justified\"\n", - "print\"ReL=\",ReL" + "print\"ReL=\",ReL\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n" ] }, { @@ -122,6 +137,10 @@ } ], "source": [ + " \n", + " \n", + " \n", + " \n", "import math\n", " \n", "print\"Introduction to heat transfer by S.K.Som, Chapter 9, Example 2\"\n", @@ -159,7 +178,19 @@ "#Re is reynolds number\n", "print\"Reynolds number is\"\n", "Re=(4*mdotc)/(mu*P)\n", - "print\"Re=\",Re" + "print\"Re=\",Re\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n" ] }, { @@ -197,6 +228,10 @@ } ], "source": [ + " \n", + " \n", + " \n", + " \n", "import math\n", " \n", "print\"Introduction to heat transfer by S.K.Som, Chapter 9, Example 3\"\n", @@ -243,7 +278,29 @@ "#v is the average flow velocity\n", "print\"Hence the average flow velocity at the trailing edge in m/s is\"\n", "v=(mdotc)/(rho*delta*B)\n", - "print\"v=\",v" + "print\"v=\",v\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n" ] }, { @@ -277,6 +334,10 @@ } ], "source": [ + " \n", + " \n", + " \n", + " \n", "import math\n", " \n", "print\"Introduction to heat transfer by S.K.Som, Chapter 9, Example 4\"\n", @@ -312,7 +373,29 @@ "#The rate of condensation is given by mdotc=(hbar*(pi*D*L)*(Tg-Tw))/hfg\n", "print\"The total rate of condensation in kg/hr\"\n", "mdotc=((hbar*(math.pi*D*L)*(Tg-Tw))/hfg)*3600\n", - "print\"mdotc=\",mdotc" + "print\"mdotc=\",mdotc\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n" ] }, { @@ -340,6 +423,10 @@ } ], "source": [ + " \n", + " \n", + " \n", + " \n", "import math\n", " \n", "print\"Introduction to heat transfer by S.K.Som, Chapter 9, Example 5\"\n", @@ -358,7 +445,15 @@ "#h is heat transfer coefficient\n", "print\"Heat transfer coefficient in W/m**2 is\"\n", "h=(E*I)/(A*(T1-T2))\n", - "print\"h=\",h" + "print\"h=\",h\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n" ] }, { @@ -388,6 +483,10 @@ } ], "source": [ + " \n", + " \n", + " \n", + " \n", "import math\n", " \n", "print\"Introduction to heat transfer by S.K.Som, Chapter 9, Example 6\"\n", @@ -414,7 +513,23 @@ "#E is the burn out voltage\n", "print\"The burn out voltage in Volts is \"\n", "E=(qc*A)/I\n", - "print\"E=\",E" + "print\"E=\",E\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n" ] }, { @@ -443,6 +558,10 @@ } ], "source": [ + " \n", + " \n", + " \n", + " \n", "import math\n", " \n", "print\"Introduction to heat transfer by S.K.Som, Chapter 9, Example 7\"\n", @@ -468,7 +587,20 @@ "print\"Heat flux q in W/m**2 is\"\n", "q=(mul*hfg)*(((rhol-rhov)*g)/sigma)**(1/2)*((cpl*(T1-T2))/(csf*hfg*Prl**n))**3 \n", "print\"The peak heat flux for water at one atmospheric pressure is qc=1.24*10**6(found in example 9.6).Since q<qc,The regime of boiling is nucleate.\"\n", - "print\"q=\",q" + "print\"q=\",q\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n" ] }, { @@ -480,7 +612,7 @@ }, { "cell_type": "code", - "execution_count": 21, + "execution_count": 1, "metadata": { "collapsed": false }, @@ -495,11 +627,15 @@ "The surface temprature in °C is\n", "Tw= 120.0\n", "The value of the coefficient csf is \n", - "csf= 0.0214423761571\n" + "csf= 0.0151329179422\n" ] } ], "source": [ + " \n", + " \n", + " \n", + " \n", "import math\n", " \n", "print\"Introduction to heat transfer by S.K.Som, Chapter 9, Example 8\"\n", @@ -540,8 +676,30 @@ "#Now we use following equation to determine csf,q=(mul*hfg)*(((rhol-rhov)*g)/sigma1)**(1/2)*((cpl*(Tw-T))/(csf*hfg*Prl**n))**3 \n", "#Manipulating above equation to find csf we get csf=((cpl*(Tw-T))/(((q/((mul*hfg)*(((rhol-rhov)*g)/sigma1)**(1/2))**(1/3))*hfg*Prl**n))\n", "print\"The value of the coefficient csf is \"\n", - "csf=((cpl*(Tw-T))/(((q/((mul*hfg)*(((rhol-rhov)*g)/sigma1)**(1/2)))**(1/3))*hfg*Prl**n))#[NOTE:The answer in the book is incorrect.(Calcultion mistake)]\n", - "print\"csf=\",csf" + "csf=((cpl*(Tw-T))/(((q/((mul*hfg)*(((rhol-rhov)*g)/sigma1)**(1.0/2)))**(1.0/3))*hfg*Prl**n))#[NOTE:The answer in the book is incorrect.(Calcultion mistake)]\n", + "print\"csf=\",csf\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n", + "\n" ] } ], diff --git a/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter9_4YOTRPU.ipynb b/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter9_4YOTRPU.ipynb deleted file mode 100644 index 7d76afa3..00000000 --- a/Introduction_to_Heat_Transfer_by_S._K._Som/Chapter9_4YOTRPU.ipynb +++ /dev/null @@ -1,727 +0,0 @@ -{ - "cells": [ - { - "cell_type": "markdown", - "metadata": { - "collapsed": true - }, - "source": [ - "# Chapter 09:Heat transfer in condensation and boiling" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex9.1:pg-392" - ] - }, - { - "cell_type": "code", - "execution_count": 17, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 9, Example 1\n", - "The properties of condensate(liquid water) are evaluated at the mean film temprature \n", - "The mean film temprature in°C is\n", - "tf= 95\n", - "hfg= 2270000.0\n", - "The average heat transfer coefficient over length L in W/(m**2*K)\n", - "hbar= 0.745\n", - "The rate of heat transfer per unit width in W/m \n", - "Q= 3.772\n", - "The total rate of condensation in kg/(s*m)\n", - "mdotc= 1.66167400881e-06\n", - "We have to check whether the flow is laminar or not \n", - "Reynolds no. is\n", - "Therefore the flow is laminar and hence the use of the equation is justified\n", - "ReL= 0.0221556534508\n" - ] - } - ], - "source": [ - " \n", - " \n", - " \n", - " \n", - "import math\n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 9, Example 1\"\n", - "#A vertical cooling fin, Approximately a flat plate length,(L)=0.4m high is exposed to saturated steam(temprature,Tg=100°C) at atmospheric pressure.\n", - "L=0.4;\n", - "Tg=100;\n", - "#The fin is maintained at temprature,Tw=90°C by cooling water.\n", - "Tw=90;\n", - "print\"The properties of condensate(liquid water) are evaluated at the mean film temprature \"\n", - "#tf is mean film temprature\n", - "print\"The mean film temprature in°C is\"\n", - "tf=(Tg+Tw)/2\n", - "print\"tf=\",tf\n", - "#The properties of condensate are density(rho=962kg/m**3),conductivity(k=0.677W/(m*K)),viscosity(mu=3*10**-4 kg/(m*s))\n", - "rho=962;\n", - "k=0.677;\n", - "mu=3*10**-4;\n", - "#The value rhov=0.598kg/m**3 and hfg=2.27*10**6J/kg at 100°C are found from steam table\n", - "#g is acceleration due to gravity =9.81m/s**2\n", - "g=9.81;\n", - "rhov=0.598;#rhov is vapour density\n", - "hfg=2.27*10**6;#hfg is enthalpy of vaporisation\n", - "print\"hfg=\",hfg\n", - "#The average heat transfer coefficient over length L is hbarL=0.943*((rho*(rho-rhov)*g*h*L**3)/(mu*k*(Tg-Tw)))**(1/4)\n", - "print\"The average heat transfer coefficient over length L in W/(m**2*K)\"\n", - "hbarL=0.943*((rho*(rho-rhov)*g*hfg*k**3)/(mu*L*(Tg-Tw)))**(1/4)\n", - "print\"hbar=\",hbar\n", - "#The rate of heat transfer per unit width is Q=hbarL*L*(Tg-Tw)\n", - "print\"The rate of heat transfer per unit width in W/m \"\n", - "Q=hbarL*L*(Tg-Tw)\n", - "print\"Q=\",Q\n", - "#The rate of condensation is given by mdotc=(Q/hfg)\n", - "print\"The total rate of condensation in kg/(s*m)\"\n", - "mdotc=(Q/hfg)\n", - "print\"mdotc=\",mdotc\n", - "print\"We have to check whether the flow is laminar or not \"\n", - "#Reynolds no is given by ReL=(4*mdotc)/(mu)\n", - "print\"Reynolds no. is\"\n", - "ReL=(4*mdotc)/(mu)\n", - "print\"Therefore the flow is laminar and hence the use of the equation is justified\"\n", - "print\"ReL=\",ReL\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex9.2:pg-393" - ] - }, - { - "cell_type": "code", - "execution_count": 16, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 9, Example 2\n", - "The mean film temprature in°C is\n", - "tf= 95\n", - "hfg= 2270000.0\n", - "The average heat transfer coefficient in W/(m**2*K)\n", - "hbar= 0.745\n", - "The total rate of condensation in kg/s\n", - "Check for reynolds no.\n", - "mdotc= 1.54657700017e-06\n", - "Reynolds number is\n", - "Re= 0.00343683777816\n" - ] - } - ], - "source": [ - " \n", - " \n", - " \n", - " \n", - "import math\n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 9, Example 2\"\n", - "#Steam is condensed at temprature(Tg=100°C) on the outer surafce of a horizontal tube of length(L=3m) and diameter(d)=50mm or .05m\n", - "Tg=100;\n", - "L=3;\n", - "D=0.05;\n", - "#The Tube surface is maintained at temprature,Tw=90°C \n", - "Tw=90;\n", - "#tf is mean film temprature\n", - "print\"The mean film temprature in°C is\"\n", - "tf=(Tg+Tw)/2\n", - "print\"tf=\",tf\n", - "#The properties of condensate are density(rho=962kg/m**3),conductivity(k=0.677W/(m*K)),viscosity(mu=3*10**-4 kg/(m*s))\n", - "rho=962;\n", - "k=0.677;\n", - "mu=3*10**-4;\n", - "#The value rhov=0.598kg/m**3 and hfg=2.27*10**6J/kg at 100°C are found from steam table\n", - "#g is acceleration due to gravity =9.81m/s**2\n", - "g=9.81;\n", - "rhov=0.598;#vapour density\n", - "hfg=2.27*10**6;#enthalpy of vaporisation\n", - "print\"hfg=\",hfg\n", - "#The average heat transfer coefficient hbar=0.745*((rho*(rho-rhov)*g*hfg*k**3)/(mu*D*(Tg-Tw)))**(1/4)\n", - "print\"The average heat transfer coefficient in W/(m**2*K)\"\n", - "hbar=0.745*((rho*(rho-rhov)*g*hfg*k**3)/(mu*D*(Tg-Tw)))**(1/4)\n", - "print\"hbar=\",hbar\n", - "#The rate of condensation is given by mdotc=(hbar*(pi*D*L)*(Tg-Tw))/hfg\n", - "print\"The total rate of condensation in kg/s\"\n", - "mdotc=(hbar*(math.pi*D*L)*(Tg-Tw))/hfg\n", - "print\"Check for reynolds no.\"\n", - "print\"mdotc=\",mdotc\n", - "#For a horizontal tube having length,L,perimeter is P=2L\n", - "P=2*L;\n", - "#Re is reynolds number\n", - "print\"Reynolds number is\"\n", - "Re=(4*mdotc)/(mu*P)\n", - "print\"Re=\",Re\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex9.3:pg-394" - ] - }, - { - "cell_type": "code", - "execution_count": 13, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 9, Example 3\n", - "The mean film temprature in°C is\n", - "tf= 80\n", - "The average heat transfer coefficient over length L in W/(m**2*K)\n", - "hbar= 0.943\n", - "The rate of heat transfer in kW \n", - "Q= 0.016974\n", - "(b)The film thickness at the trailing edges in m is\n", - "delta= 1.0\n", - "The total rate of condensation in kg/s\n", - "mdotc= 7.47753303965e-06\n", - "Hence the average flow velocity at the trailing edge in m/s is\n", - "v= 2.56431174199e-08\n" - ] - } - ], - "source": [ - " \n", - " \n", - " \n", - " \n", - "import math\n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 9, Example 3\"\n", - "#A vertical plate having length,(L)=1.5m is maintained at temprature(Tw) of 60°C in the presence of saturated steam(temprature,Tg=100°C) at atmospheric pressure.\n", - "L=1.5;\n", - "Tg=100;\n", - "Tw=60;\n", - "#Consider the width of plate to be (B)=0.3m\n", - "B=0.3;\n", - "#tf is the mean film temprature\n", - "print\"The mean film temprature in°C is\"\n", - "tf=(Tg+Tw)/2\n", - "print\"tf=\",tf\n", - "#The relevant properties are desity(rho=972kg/m**3),conductivity(k=0.670W/(m*K)),viscosity(mu=3.54*10**-4 kg/(m*s))\n", - "#specific heat(cp=4.2J/(kg*K)),vapur density(rhov(100°C)=0.598k/m**3),Enthalpy of vaporisation(hfg(100°C)=2.27*10**6J/kg)\n", - "#g is acceleration due to gravity =9.81m/s**2\n", - "g=9.81;\n", - "rho=972;\n", - "k=0.670;\n", - "mu=3.54*10**-4;\n", - "cp=4.2;\n", - "rhov=0.598;\n", - "hfg=2.27*10**6;\n", - "#The average heat transfer coefficient over length L is hbar=0.943*((rho*(rho-rhov)*g*h*L**3)/(mu*k*(Tg-Tw)))**(1/4)\n", - "print\"The average heat transfer coefficient over length L in W/(m**2*K)\"\n", - "hbar=0.943*((rho*(rho-rhov)*g*hfg*k**3)/(mu*L*(Tg-Tw)))**(1/4)\n", - "print\"hbar=\",hbar\n", - "#The rate of heat transfer Q=hbarL*A*(Tg-Tw)\n", - "#Area(A)=L*B\n", - "A=L*B;\n", - "print\"The rate of heat transfer in kW \"\n", - "Q=(hbar*A*(Tg-Tw))/1000\n", - "print\"Q=\",Q\n", - "#The film thickness at the trailing edges is found out by delta=((4*mu*k*x*(Tg-Tw))/(g*hfg*rho*(rho-rhov)))**(1/4)\n", - "print\"(b)The film thickness at the trailing edges in m is\"\n", - "#at trailing edges x=1.5m\n", - "x=1.5;\n", - "delta=((4*mu*k*x*(Tg-Tw))/(g*hfg*rho*(rho-rhov)))**(1/4)\n", - "print\"delta=\",delta\n", - "#The rate of condensation is given by mdotc=(Q/hfg)\n", - "print\"The total rate of condensation in kg/s\"\n", - "mdotc=((Q*1000)/hfg)\n", - "print\"mdotc=\",mdotc\n", - "#v is the average flow velocity\n", - "print\"Hence the average flow velocity at the trailing edge in m/s is\"\n", - "v=(mdotc)/(rho*delta*B)\n", - "print\"v=\",v\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex9.4:pg-396" - ] - }, - { - "cell_type": "code", - "execution_count": 11, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 9, Example 4\n", - "The mean film temprature in°C is\n", - "tf= 30\n", - " Modified enthalpy in J/kg is\n", - "hfgdash= 131330.0\n", - "The average heat transfer coefficient over length L in W/(m**2*K)\n", - "hbar= 0.555\n", - "The total rate of condensation in kg/hr\n", - "mdotc= 0.00716923260703\n" - ] - } - ], - "source": [ - " \n", - " \n", - " \n", - " \n", - "import math\n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 9, Example 4\"\n", - "#Saturated freon-012 at Temprature(Tg)=35°C is condensed horizontal tube of diameter(D)=15mm or.015m at a lower vapour velocity.\n", - "#length,L=1m,Since per meter of tube is considered.\n", - "L=1;\n", - "Tg=35;\n", - "D=0.015;\n", - "#The tube wall is maintained at temprature(Tw)=25°C\n", - "Tw=25;\n", - "#For freon-12 at 35°C,enthalpy of vaporisation(hfg=131.33kJ/kg) and vapour density(rhov=42.68kg/m**3)\n", - "hfg=131.33*10**3;\n", - "rhov=42.68;\n", - "#tf is mean film temprature\n", - "print\"The mean film temprature in°C is\"\n", - "tf=(Tg+Tw)/2\n", - "print\"tf=\",tf\n", - "#The relevant properties at 30°C are density(rho=1.29*10**3kg/m**3),conductivity(k=0.071W/(mK)),viscosity(mu=2.50*10**-4kg/(m*s)),specific heat(cp=983J/(kg*°C))\n", - "rho=1.29*10**3;\n", - "k=0.071;\n", - "mu=2.50*10**-4;\n", - "cp=983;\n", - "#g is acceleration due to gravity =9.81m/s**2\n", - "g=9.81;\n", - "#we found the modified enthalpy by using following equation hfgdash=hfg+(3/8)*cp*(Tg-Tw)\n", - "print\" Modified enthalpy in J/kg is\"\n", - "hfgdash=hfg+((3/8)*cp*(Tg-Tw))\n", - "print\"hfgdash=\",hfgdash\n", - "#The average heat transfer coefficient over length L is hbar=0.555*((rho*(rho-rhov)*g*hfgdash*k**3)/(mu*D*(Tg-Tw)))**(1/4)\n", - "print\"The average heat transfer coefficient over length L in W/(m**2*K)\"\n", - "hbar=0.555*((rho*(rho-rhov)*g*hfgdash*k**3)/(mu*D*(Tg-Tw)))**(1/4)\n", - "print\"hbar=\",hbar\n", - "#The rate of condensation is given by mdotc=(hbar*(pi*D*L)*(Tg-Tw))/hfg\n", - "print\"The total rate of condensation in kg/hr\"\n", - "mdotc=((hbar*(math.pi*D*L)*(Tg-Tw))/hfg)*3600\n", - "print\"mdotc=\",mdotc\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex9.5:pg-397" - ] - }, - { - "cell_type": "code", - "execution_count": 7, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 9, Example 5\n", - "Heat transfer coefficient in W/m**2 is\n", - "h= 105042.262441\n" - ] - } - ], - "source": [ - " \n", - " \n", - " \n", - " \n", - "import math\n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 9, Example 5\"\n", - "#A nickel wire of length(L)=0.1m,Diameter(D)=1mm or .001m \n", - "#Submerged horizontally in water at pressure=1 atm(101kPa) requires current,I=150A at voltage ,E=2.2V to maintain wire at temprature(T1)=110°C\n", - "L=0.1;\n", - "T1=110;\n", - "D=0.001;\n", - "I=150;\n", - "E=2.2;\n", - "#Area(A)=(math.pi*D*L)\n", - "A=math.pi*D*L;\n", - "#The saturation temprature of water at one atmospheric pressure(101kPa) is T2=100°C.\n", - "T2=100;\n", - "#We can write from energy balance E*I=h*A*(T1-T2),we can find heat transfer coefficient from it.\n", - "#h is heat transfer coefficient\n", - "print\"Heat transfer coefficient in W/m**2 is\"\n", - "h=(E*I)/(A*(T1-T2))\n", - "print\"h=\",h\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex9.6:pg-398" - ] - }, - { - "cell_type": "code", - "execution_count": 18, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 9, Example 6\n", - "Critical Heat flux in W/m**2 is\n", - "qc= 202044.0\n", - "The burn out voltage in Volts is \n", - "E= 1.90421983831\n" - ] - } - ], - "source": [ - " \n", - " \n", - " \n", - " \n", - "import math\n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 9, Example 6\"\n", - "#In a laboratory experiment,A current(I)=100A burns out a nickel wire having Diameter(D)=1mm or 0.001mm,length(L)=0.3m\n", - "I=100;\n", - "D=.001;\n", - "L=0.3;\n", - "#It is submerged horizontally in water at one atmospheric pressure.\n", - "#For saturated water at one atmospheric pressure,density(rhol=960kg/m**3),vapour density(rhov=0.60kg/m**3),enthalpy of vaporisation(hfg=2.26*10**6J/kg),surface tension(sigma=0.055N/m).\n", - "rhol=960;\n", - "rhov=0.60;\n", - "hfg=2.26*10**6;\n", - "sigma=0.055;\n", - "#Area(A)=(pi*D*L)\n", - "A=math.pi*D*L;\n", - "#g is acceleration due to gravity =9.81m/s**2\n", - "g=9.81;\n", - "#The wire is burnt out when heat reaches its peak\n", - "#We use following expression to determine critical heat flux qc=0.149*hfg*rhov*((sigma*g*(rhol-rhov))/rhov**2)**(1/4)*((rhol+rhov)/rhol)**(1/2) \n", - "print\"Critical Heat flux in W/m**2 is\"\n", - "qc=0.149*hfg*rhov*((sigma*g*(rhol-rhov))/rhov**2)**(1/4)*((rhol+rhov)/rhol)**(1/2) \n", - "print\"qc=\",qc\n", - "#From the energy balance E*I=qc*A\n", - "#E is the burn out voltage\n", - "print\"The burn out voltage in Volts is \"\n", - "E=(qc*A)/I\n", - "print\"E=\",E\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex9.7:pg-399" - ] - }, - { - "cell_type": "code", - "execution_count": 19, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 9, Example 7\n", - "Heat flux q in W/m**2 is\n", - "The peak heat flux for water at one atmospheric pressure is qc=1.24*10**6(found in example 9.6).Since q<qc,The regime of boiling is nucleate.\n", - "q= 3636.07255495\n" - ] - } - ], - "source": [ - " \n", - " \n", - " \n", - " \n", - "import math\n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 9, Example 7\"\n", - "#A heated nickel plate at temprature (T1)=110°C is submereged in water at one atmospheric pressure.\n", - "T1=110;\n", - "#For nucleate boiling coefficient(csf=0.006) and n=1\n", - "csf=0.006;\n", - "n=1;\n", - "#For saturated water at one atmospheric pressure,density of liquid(rhol=960kg/m**3),vapour density(rhov=0.60kg/m**3)\n", - "#enthalpy of vaporisation(hfg=2.26*10**6J/kg),surface tension(sigma=0.055N/m),saturation temprature(T2)=100°C\n", - "T2=100;\n", - "rhol=960;\n", - "rhov=0.60;\n", - "hfg=2.26*10**6;\n", - "sigma=0.055;\n", - "#g is acceleration due to gravity =9.81m/s**2\n", - "g=9.81;\n", - "#We take specific heat of liquid(cpl=4.216kJ/(kg*K)),prandtl number of liquid(Prl=1.74),viscosity of liquid(mul=2.82*10**-4kg/(m*s))\n", - "cpl=4.216*10**3;\n", - "Prl=1.74;\n", - "mul=2.82*10**-4;\n", - "#The heat flux q is given by expression q=(mul*hfg)*(((rhol-rhov)*g)/sigma)**(1/2)*((cpl*(T1-T2))*(csf*hfg*prl**n))**3 \n", - "print\"Heat flux q in W/m**2 is\"\n", - "q=(mul*hfg)*(((rhol-rhov)*g)/sigma)**(1/2)*((cpl*(T1-T2))/(csf*hfg*Prl**n))**3 \n", - "print\"The peak heat flux for water at one atmospheric pressure is qc=1.24*10**6(found in example 9.6).Since q<qc,The regime of boiling is nucleate.\"\n", - "print\"q=\",q\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n" - ] - }, - { - "cell_type": "markdown", - "metadata": {}, - "source": [ - "## Ex9.8:pg-401" - ] - }, - { - "cell_type": "code", - "execution_count": 1, - "metadata": { - "collapsed": false - }, - "outputs": [ - { - "name": "stdout", - "output_type": "stream", - "text": [ - "Introduction to heat transfer by S.K.Som, Chapter 9, Example 8\n", - "The heat flux in W/m**2 is\n", - "q= 750000.0\n", - "The surface temprature in °C is\n", - "Tw= 120.0\n", - "The value of the coefficient csf is \n", - "csf= 0.0151329179422\n" - ] - } - ], - "source": [ - " \n", - " \n", - " \n", - " \n", - "import math\n", - " \n", - "print\"Introduction to heat transfer by S.K.Som, Chapter 9, Example 8\"\n", - "#A Copper bar whose one end is exposed to boiling water while the other end is encapsulated by an electric heater.\n", - "#Thermocouples are inserted in the bar to measure the tempratures at two locations A and b at distances xA=10mm and xB=30mm from the surface.\n", - "xA=.010;\n", - "xB=.030;\n", - "#Under steady condition nucleate boiling is maintained in saturated water at atmospheric pressure and the tempratures are TA=140°C and TB=180°C,n=1\n", - "TA=140;\n", - "TB=180;\n", - "n=1;\n", - "#The values of relevant properties of water and other parameters are \n", - "#density of liquid(rhol=960kg/m**3),vapour density(rhov=0.60kg/m**3),specific heat of liquid(cpl=4.216 kJ/(kg*K))\n", - "#enthalpy of vaporisation(hfg=2.26*106J/kg),prandtl number of liquiid(Prl=1.74),viscosity of liquid(mul=2.82*10**-4kg/(m*s)),surface tension(sigma1=0.055N/m).\n", - "rhol=960;\n", - "rhov=0.60;\n", - "cpl=4.216*10**3;\n", - "hfg=2.26*10**6;\n", - "Prl=1.74;\n", - "mul=2.82*10**-4;\n", - "sigma1=0.055;\n", - "#We have to know the value of heat flux(q) and the surface temprature(Tw).\n", - "#Since we know the tempratures at location A and B,The heat flux q is determined by fourier law of heat conduction in the bar at steady-state as\n", - "#q=k*((TB-TA)/(xB-xA))\n", - "#We take for copper conductivity,k=375W/(m*K)\n", - "k=375;\n", - "print\"The heat flux in W/m**2 is\"\n", - "q=k*((TB-TA)/(xB-xA))\n", - "print\"q=\",q\n", - "#g is acceleration due to gravity =9.81m/s**2\n", - "g=9.81;\n", - "#The surface temprature is given by Tw=TA-((TB-TA)/(xB-xA))*xA\n", - "print\"The surface temprature in °C is\"\n", - "Tw=TA-((TB-TA)/(xB-xA))*xA\n", - "print\"Tw=\",Tw\n", - "#Temprature,T=100°C,since copper bar is exposed to boiling water. \n", - "T=100;\n", - "#Now we use following equation to determine csf,q=(mul*hfg)*(((rhol-rhov)*g)/sigma1)**(1/2)*((cpl*(Tw-T))/(csf*hfg*Prl**n))**3 \n", - "#Manipulating above equation to find csf we get csf=((cpl*(Tw-T))/(((q/((mul*hfg)*(((rhol-rhov)*g)/sigma1)**(1/2))**(1/3))*hfg*Prl**n))\n", - "print\"The value of the coefficient csf is \"\n", - "csf=((cpl*(Tw-T))/(((q/((mul*hfg)*(((rhol-rhov)*g)/sigma1)**(1.0/2)))**(1.0/3))*hfg*Prl**n))#[NOTE:The answer in the book is incorrect.(Calcultion mistake)]\n", - "print\"csf=\",csf\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n", - "\n" - ] - } - ], - "metadata": { - "kernelspec": { - "display_name": "Python 2", - "language": "python", - "name": "python2" - }, - "language_info": { - "codemirror_mode": { - "name": "ipython", - "version": 2 - }, - "file_extension": ".py", - "mimetype": "text/x-python", - "name": "python", - "nbconvert_exporter": "python", - "pygments_lexer": "ipython2", - "version": "2.7.11" - } - }, - "nbformat": 4, - "nbformat_minor": 0 -} |