From f270f72badd9c61d48f290c3396004802841b9df Mon Sep 17 00:00:00 2001 From: kinitrupti Date: Fri, 12 May 2017 18:53:46 +0530 Subject: Removed duplicates --- .../Chapter_6_Heat_Transfer_by.ipynb | 344 +++++++++++++++++++++ 1 file changed, 344 insertions(+) create mode 100755 Textbook_Of_Heat_Transfer/Chapter_6_Heat_Transfer_by.ipynb (limited to 'Textbook_Of_Heat_Transfer/Chapter_6_Heat_Transfer_by.ipynb') diff --git a/Textbook_Of_Heat_Transfer/Chapter_6_Heat_Transfer_by.ipynb b/Textbook_Of_Heat_Transfer/Chapter_6_Heat_Transfer_by.ipynb new file mode 100755 index 00000000..8e90d8f1 --- /dev/null +++ b/Textbook_Of_Heat_Transfer/Chapter_6_Heat_Transfer_by.ipynb @@ -0,0 +1,344 @@ +{ + "metadata": { + "name": "", + "signature": "sha256:aaada7e9a1621c5448fcc2c4bafb69518918476f74efee2f04521ed97f085e1c" + }, + "nbformat": 3, + "nbformat_minor": 0, + "worksheets": [ + { + "cells": [ + { + "cell_type": "heading", + "level": 1, + "metadata": {}, + "source": [ + "Chapter 6: Heat Transfer by Natural convection" + ] + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 6.1, Page no:258" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math\n", + "from __future__ import division\n", + "\n", + "#Variable declaration\n", + "H = 0.5 ; #m\n", + "Th = 100; #degree C\n", + "Tl = 40; #degree C\n", + "Pr = 0.694;\n", + "k = 0.0297; #W/m K\n", + "\n", + "#calculations\n", + "v = 20.02*10**-6 ; #m/s\n", + "T = (Th+ Tl )/2 + 273 ; #K\n", + "B = 1/T;\n", + "Gr = 9.81* B *(( Th - Tl )*H**3) /(v**2) ;\n", + "Ra = Gr*Pr;\n", + "Nua = 0.64*( Gr**(1/4) )*( Pr**0.5) *((0.861+ Pr)**( -1/4) ); #Exact analysis\n", + "Nub = 0.68*( Gr**(1/4) )*( Pr**0.5) *((0.952+ Pr)**( -1/4) ); #Integral method\n", + "Nuc = 0.59*( Ra)**(1/4) ; #McAdams correlation\n", + "Nud = 0.68 + 0.670*( Ra**(1/4) ) /(1+(0.492/ Pr)**(9/16))**(4/9) ; #Churchill and Chu correlation\n", + "\n", + "#result\n", + "print\"Mean film temperature =\",round(T,4),\"K\";\n", + "print\" ( a ) \";\n", + "print\"Exact analysis\";\n", + "print\"NuL =\",round(Nua,4);\n", + "print\"\\n ( b ) \";\n", + "print\"Integral method\";\n", + "print\"NuL =\",round(Nub,4);\n", + "print\"\\n ( c ) \";\n", + "print\"McAdams correlation\";\n", + "print\"NuL =\",round(Nuc,4);\n", + "print\"\\n ( d ) \";\n", + "print\"Churchill and Chu correlation\";\n", + "print\"NuL =\",round(Nud,4);" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Mean film temperature = 343.0 K\n", + " ( a ) \n", + "Exact analysis\n", + "NuL = 72.6196\n", + "\n", + " ( b ) \n", + "Integral method\n", + "NuL = 76.0691\n", + "\n", + " ( c ) \n", + "McAdams correlation\n", + "NuL = 81.9066\n", + "\n", + " ( d ) \n", + "Churchill and Chu correlation\n", + "NuL = 71.887\n" + ] + } + ], + "prompt_number": 1 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 6.3, Page no:260" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math\n", + "from __future__ import division\n", + "\n", + "#Variable declaration\n", + "s = 0.2 ; #m\n", + "d = 0.005 ; #m\n", + "rho = 7900 ; #kg/m^3\n", + "Cp = 460 ; #J/kg K\n", + "Tair = 20 ; #C\n", + "Tavg = 380 ; #C\n", + "Pr = 0.680 ;\n", + "k = 0.0393 ; #W/m K\n", + "h2 = 7.348 ; #W/m^2 K\n", + "h3 = 6.780; #W/m^2 K\n", + "\n", + "#calculations\n", + "Tm = ( Tavg + Tair )/2 ; #C\n", + "v = 34.85*10**-6 ; #m^2/s\n", + "Re = 9.81*1/(273+ Tm)*( Tavg - Tair )*(s**3) /(v**2) *Pr;\n", + "Nu = 0.68 + 0.670*( Re**(1/4) ) /(1+(0.492/ Pr)**(4/9))**(4/9) ;\n", + "h = Nu*k/s; #W/m^2 K\n", + "t1 = rho*s*s*d*Cp /(( s**2) *2*h)* math.log ((430 - Tair )/(330 -Tair )); #s\n", + "t2 = rho*s*s*d*Cp /(( s**2) *2* h2)* math.log ((330 - Tair )/(230 -Tair )); #s\n", + "t3 = rho*s*s*d*Cp /(( s**2) *2* h3)* math.log ((230 - Tair )/(130 -Tair )); #s\n", + "time = t1+t2+t3; #Total time\n", + "minute = time /60;\n", + "\n", + "#result\n", + "print\"Time required for the plate to cool from 430 C to 330 C is\",round(t1,4),\"s\";\n", + "print\"Time required for the plate to cool from 330 C to 230 C is\",round(t2,4),\"s\";\n", + "print\"Time required for the plate to cool from 230 C to 130 C is\",round(t3,4),\"s\";\n", + "print\"Hence, time required for the plate to cool from 430 C to 130 C\";\n", + "print\" =\",round(time,4),\"s\";\n", + "print\" =\",round(minute,4),\"min\";" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Time required for the plate to cool from 430 C to 330 C is 328.9673 s\n", + "Time required for the plate to cool from 330 C to 230 C is 481.5307 s\n", + "Time required for the plate to cool from 230 C to 130 C is 866.4613 s\n", + "Hence, time required for the plate to cool from 430 C to 130 C\n", + " = 1676.9593 s\n", + " = 27.9493 min\n" + ] + } + ], + "prompt_number": 2 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 6.4, Page no:264" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math\n", + "from __future__ import division\n", + "\n", + "#Variable declaration\n", + "D = 0.006 ; #m\n", + "e = 0.1 ;\n", + "Ti = 800 ; #C\n", + "Ta = 1000 ; #C\n", + "k = 0.0763 ; #W/m K\n", + "Pr = 0.717 ;\n", + "Ra2 = 6.42 ;\n", + "Nu2 = 0.9841 ;\n", + "h2 = 12.15 ;\n", + "Ra3 = 6.93 ;\n", + "Nu3 = 0.9963 ;\n", + "h3 = 12.33 ;\n", + "\n", + "#calculations\n", + "Tm = (Ta+Ti) /2;\n", + "v = 155.1*10**-6 ; #m^2/s\n", + "Gr = 9.81*1/1173*(200* D**3) /(v**2) ;\n", + "Ra = Gr*Pr ;\n", + "Nu = 0.36 + 0.518*( Ra**(1/4) ) /(1+(0.559/ Pr)**(9/16))**(4/9) ;\n", + "h = Nu*k/D;\n", + "x = h*(Ta -Ti); #W/m^2\n", + "x2 = h2 *(900 -800) ;\n", + "x3 = h3 *(910 -800) ;\n", + "T = 900 + (910 -900) *(1306 - x2)/(x3 -x2); #Interpolation\n", + "\n", + "#result\n", + "print\"Trial 1\";\n", + "print\"Let Ta =10000 C\";\n", + "print\"Value of h(Ta-800) =\",round(x,4),\"W/m^2, which is much larger than the required value of 1306 W/m^2\";\n", + "print\"\\nTrial 2\";\n", + "print\"Let Ta = 900 C\";\n", + "print\"Value of h(Ta-800) =\",round(x2,4),\"W/m^2, which is a little less than the required value of 1306 W/m^2\";\n", + "print\"\\nTrial 3\";\n", + "print\"Let Ta = 910 C\";\n", + "print\"Value of h(Ta-800) =\",round(x3,4),\"W/m^2 \\nThis value is little more than the required value of 1306 W/m^2\";\n", + "print\"\\nThe correct value of Ta obtained by interpolation is\",round(T,4),\"C\";" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Trial 1\n", + "Let Ta =10000 C\n", + "Value of h(Ta-800) = 2722.8585 W/m^2, which is much larger than the required value of 1306 W/m^2\n", + "\n", + "Trial 2\n", + "Let Ta = 900 C\n", + "Value of h(Ta-800) = 1215.0 W/m^2, which is a little less than the required value of 1306 W/m^2\n", + "\n", + "Trial 3\n", + "Let Ta = 910 C\n", + "Value of h(Ta-800) = 1356.3 W/m^2 \n", + "This value is little more than the required value of 1306 W/m^2\n", + "\n", + "The correct value of Ta obtained by interpolation is 906.4402 C\n" + ] + } + ], + "prompt_number": 3 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 6.5, Page no:269" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math\n", + "from __future__ import division\n", + "\n", + "#Variable declaration\n", + "Tp = 75 ; #Temperature of absorber plate , degree C\n", + "Tc = 55 ; #Temperature of glass cover , degree C\n", + "L = 0.025 ; #m\n", + "H = 2 ; #m\n", + "Y = 70 ; #degree\n", + "k = 0.0294 ; #W/m K\n", + "Pr = 0.695 ;\n", + "\n", + "#calculations\n", + "a = 19/180*3.14 ; #Radians\n", + "r = H/L ;\n", + "Tavg = ( Tp +Tc) /2+273 ; #K\n", + "v = 19.50*10**-6 ; #m^2/s\n", + "Ra = 9.81*(1/ Tavg )*( Tp -Tc)*(L**3) /(v**2) *Pr*math.cos(a);\n", + "Nu = 0.229*( Ra)**0.252;\n", + "h = Nu*k/L ; #W/m^2 K\n", + "Rate = h *2*1*( Tp -Tc); #W\n", + "\n", + "#result\n", + "print\"Heat transfer rate =\",round(Rate,4),\"W\";" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Heat transfer rate = 122.8843 W\n" + ] + } + ], + "prompt_number": 4 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 6.6, Page no:270" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math\n", + "from __future__ import division\n", + "\n", + "#Variable declaration\n", + "Tair = 30 ;\n", + "D = 0.04 ;\n", + "Ts = 70 ;\n", + "V = 0.3 ;\n", + "Pr = 0.698 ;\n", + "k = 0.0283 ;\n", + "\n", + "#calculations\n", + "Tm = ( Tair + Ts )/2 ;\n", + "v = 17.95*10**-6 ;\n", + "Gr = 9.81*1/323*( Ts - Tair )*(D**3) /v**2;\n", + "Re = V*D/v ;\n", + "X = Gr/Re**2 ;\n", + "Nuforced = 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", + "Nu = Nuforced *(1+6.275*( X)**(7/4))**(1/7) ;\n", + "h = Nu *(k/D);\n", + "\n", + "#result\n", + "print\"Since Gr/Re^2 =\",round(X,4),\"is > 0.2, we have a combined convection situation.\";\n", + "print\"The Average heat transfer coefficient =\",round(h,4),\"W/m^2 K\";" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Since Gr/Re^2 = 0.5399 is > 0.2, we have a combined convection situation.\n", + "The Average heat transfer coefficient = 10.8276 W/m^2 K\n" + ] + } + ], + "prompt_number": 5 + } + ], + "metadata": {} + } + ] +} \ No newline at end of file -- cgit