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diff --git a/Fundamentals_Of_Engineering_Heat_And_Mass_Transfer/README.txt b/Fundamentals_Of_Engineering_Heat_And_Mass_Transfer/README.txt new file mode 100755 index 00000000..c62d8c2b --- /dev/null +++ b/Fundamentals_Of_Engineering_Heat_And_Mass_Transfer/README.txt @@ -0,0 +1,10 @@ +Contributed By: Hiren Shah +Course: mca +College/Institute/Organization: Financial Technology +Department/Designation: Developer +Book Title: Fundamentals Of Engineering Heat And Mass Transfer +Author: R. C. Sachdeva +Publisher: New Age Science Ltd., New Delhi +Year of publication: 2009 +Isbn: 9781906574123 +Edition: 4
\ No newline at end of file diff --git a/Fundamentals_Of_Engineering_Heat_And_Mass_Transfer/ch1.ipynb b/Fundamentals_Of_Engineering_Heat_And_Mass_Transfer/ch1.ipynb new file mode 100755 index 00000000..8a321701 --- /dev/null +++ b/Fundamentals_Of_Engineering_Heat_And_Mass_Transfer/ch1.ipynb @@ -0,0 +1,260 @@ +{ + "metadata": { + "name": "", + "signature": "sha256:756d82bd4f6b1c40b9796c02104f4ba9dd307f7a3eb5083116664c3ed159b9c9" + }, + "nbformat": 3, + "nbformat_minor": 0, + "worksheets": [ + { + "cells": [ + { + "cell_type": "heading", + "level": 1, + "metadata": {}, + "source": [ + "Chapter 1 : Basic Concepts" + ] + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 1.1 Page No : 9" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "L = 0.02;\t\t \t#Thicness of stainless steel plate in m\n", + "T = [550,50];\t\t\t#Temperatures at both the faces in degree C\n", + "k = 19.1;\t\t \t#Thermal Conductivity of stainless steel at 300 degree C in W/m.K\n", + " \n", + "# Calculations\n", + "q = ((k*(T[0]-T[1]))/(L*1000));\t\t\t#Heat transfered per uni area in kW/m**2\n", + "\n", + "# Results\n", + "print 'The heat transfered through the material per unit area is %3.1f kW/m**2'%(q)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "The heat transfered through the material per unit area is 477.5 kW/m**2\n" + ] + } + ], + "prompt_number": 1 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 1.2 Page No : 11" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "L = 1.;\t\t\t#Length of the flat plate in m\n", + "w = 0.5;\t\t\t#Width of the flat plate in m\n", + "T = 30.;\t\t\t#Air stream temperature in degree C\n", + "h = 30.;\t\t\t#Convective heat transfer coefficient in W/m**2.K\n", + "Ts = 300.;\t\t\t#Temperature of the plate in degree C\n", + "\n", + "# Calculations\n", + "A = (L*w) \t\t\t#Area of the plate in m**2\n", + "Q = (h*A*(Ts-T)/(1000));\t\t\t#Heat transfer in kW\n", + "\n", + "# Results\n", + "print 'Heat transfer rate is %3.2f kW'%(Q)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Heat transfer rate is 4.05 kW\n" + ] + } + ], + "prompt_number": 2 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 1.3 Page No : 11" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "T = 55.\t\t\t#Surface temperature in degree C\n", + "\n", + "# Calculations\n", + "q = (5.6697*10**-8*(273+T)**4)/1000;\t\t\t#The rate at which the radiator emits radiant heat per unit area if it behaves as a black body in kW/m**2\n", + "\n", + "# Results\n", + "print 'The rate at which the radiator emits radiant heat per unit area is %3.2f kW/m**2'%(q)\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "The rate at which the radiator emits radiant heat per unit area is 0.66 kW/m**2\n" + ] + } + ], + "prompt_number": 1 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 1.5 Page No : 20" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "k = 0.145;\t\t\t#Thermal conductivity of Firebrick in W/m.K\n", + "e = 0.85;\t\t\t#Emissivity\n", + "L = 0.145;\t\t\t#Thickness of the wall in m\n", + "Tg = 800.;\t\t\t#Gas temperature in degree C\n", + "Twg = 798.;\t\t\t#Wall temperature ion gas side in degree C\n", + "hg = 40.;\t\t\t#Film conductance on gas side in W/m**2.K\n", + "hc = 10.;\t\t\t#Film conductance on coolant side in W/m**2.K\n", + "F = 1.; \t\t\t#Radiation Shape factor between wall and gas\n", + "\n", + "# Calculations\n", + "R1 = (((e*5.67*10**-8*F*((Tg+273)**4-(Twg+273)**4))/(Tg-Twg))+(1./hg));\t\t\t#Thermal resistance inverse\n", + "R2 = (L/k); \t \t\t#Thermal resistance\n", + "R3 = (1./hc);\t \t \t#Thermal resistance\n", + "U = 1./((1./R1)+R2+R3);\t\t\t#Overall heat transfer coefficient in W/m**2.K\n", + "\n", + "# Results\n", + "print 'Overall heat transfer coefficient is %3.3f W/m**2.K'%(U)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Overall heat transfer coefficient is 0.906 W/m**2.K\n" + ] + } + ], + "prompt_number": 4 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 1.6 Page No : 21" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "D = 0.05;\t\t\t#Outside diameter of the pipe in m\n", + "e = 0.8;\t\t\t#Emmissivity\n", + "T = 30;\t\t\t#Room Temperature in degree C\n", + "Ts = 250;\t\t\t#Surface temperature in degree C\n", + "h = 10;\t\t\t#Convective heat transfer coefficient in W/m**2.K\n", + "\n", + "# Calculations\n", + "q = ((h*3.14*D*(Ts-T))+(e*3.14*D*5.67*10**-8*((Ts+473)**4-(T+273)**4)));\t\t\t#Heat loss per unit length of pipe in W/m\n", + "\n", + "# Results\n", + "print 'Heat loss per unit length of pipe is %3.1f W/m'%(q) \n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Heat loss per unit length of pipe is 2231.3 W/m\n" + ] + } + ], + "prompt_number": 5 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 1.7 Page No : 21" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "A = 0.1;\t\t\t#Surface area of water heater in m**2\n", + "Q = 1000.;\t\t\t#Heat transfer rate in W\n", + "Twater = 40;\t\t\t#Temperature of water in degree C\n", + "h1 = 300;\t\t\t#Heat transfer coefficient in W/m**2.K\n", + "Tair = 40;\t\t\t#Temperature of air in degree C\n", + "h2 = 9;\t\t\t#Heat transfer coefficient in W/m**2.K \n", + "\n", + "# Calculations\n", + "Tsw = (Q/(h1*A))+Twater;\t\t\t#Temperature when used in water in degree C\n", + "Tsa = (Q/(h2*A))+Tair;\t\t\t#Temperature when used in air in degree C\n", + "\n", + "# Results\n", + "print 'Temperature when used in water is %3.1f degree C \\n \\\n", + "Temperature when used in air is %i degree C'%(Tsw,Tsa)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Temperature when used in water is 73.3 degree C \n", + " Temperature when used in air is 1151 degree C\n" + ] + } + ], + "prompt_number": 7 + } + ], + "metadata": {} + } + ] +}
\ No newline at end of file diff --git a/Fundamentals_Of_Engineering_Heat_And_Mass_Transfer/ch10.ipynb b/Fundamentals_Of_Engineering_Heat_And_Mass_Transfer/ch10.ipynb new file mode 100755 index 00000000..a0d3a1bb --- /dev/null +++ b/Fundamentals_Of_Engineering_Heat_And_Mass_Transfer/ch10.ipynb @@ -0,0 +1,1000 @@ +{ + "metadata": { + "name": "", + "signature": "sha256:4a3273e6ea6b2958563a9e1b4fdabb424a50f820382694523b368d9f9ad6e27a" + }, + "nbformat": 3, + "nbformat_minor": 0, + "worksheets": [ + { + "cells": [ + { + "cell_type": "heading", + "level": 1, + "metadata": {}, + "source": [ + "Chapter 10 : Radiative Heat exchange between surfaces" + ] + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 10.1 Page No : 403" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math \n", + "\n", + "# Variables\n", + "I = 1350;\t\t\t#Solar Irradiation in W/m**2\n", + "L = (1.5*10**8);\t\t\t#Approximate dismath.tance in km\n", + "D = (1.39*10**6);\t\t\t#Approximate diameter in km\n", + "\n", + "\n", + "# Calculations\n", + "E = (I*(L*1000)**2*3.14)/((3.14/4)*(D*1000)**2);\t\t\t#Emissive power of Earth \n", + "Ts = (E/(5.67*10**-8))**0.25;\t\t\t#Surface temperature of sun in K\n", + "\n", + "# Results\n", + "print 'Surface temperature of sun is %d K'%(Ts)\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Surface temperature of sun is 5770 K\n" + ] + } + ], + "prompt_number": 1 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 10.4 Page No : 409" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "S = 1;\t\t\t#Side of a square in m\n", + "L = 0.4;\t\t\t#Distance between the plates in m\n", + "T1 = 900;\t\t\t#Temperature of one plate in degree C\n", + "T2 = 400;\t\t\t#Temperature of the other plate in degree C\n", + "\n", + "# Calculations\n", + "R = (S/L);\t\t\t#Ratio of the side of the square to the distance between plates\n", + "F12 = 0.415;\t\t\t#From Fig.10.4 on page no.409\n", + "Q = (5.67*10**-8*S*S*F12*((T1+273)**4-(T2+273)**4))/1000;\t\t\t#The net heat transfer in kW\n", + "\n", + "# Results\n", + "print 'The net exchange of energy due to radiation between the plates is %3.1f kW'%(Q)\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "The net exchange of energy due to radiation between the plates is 39.7 kW\n" + ] + } + ], + "prompt_number": 3 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 10.5 Page No : 411" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "A51 = 2;\t\t\t#Ratio of areas A5 and A1\n", + "A21 = 1;\t\t\t#Ratio of areas A2 and A1\n", + "F56 = 0.15;\t\t\t#Shape factor\n", + "F53 = 0.11;\t\t\t#Shape factor\n", + "F26 = 0.24;\t\t\t#Shape Factor\n", + "F23 = 0.2;\t\t\t#Shape Factor\n", + "\n", + "# Calculations\n", + "F14 = (A51*(F56-F53))-(A21*(F26-F23));\t\t\t#Shape factor\n", + "\n", + "# Results\n", + "print 'Shape factor F14 is %3.2f'%(F14)\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Shape factor F14 is 0.04\n" + ] + } + ], + "prompt_number": 4 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 10.8 Page No : 415" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "Th = 40.;\t\t\t#Radiating heating panel in degree C\n", + "Tb = 5.;\t\t\t#Temperature of black plane in degree C\n", + "Tc = 31.;\t\t\t#Temperature of ceiling in degree C\n", + "A = (10.*12);\t\t#Area in m**2\n", + "\n", + "# Calculations\n", + "F56 = 0.075;\t\t\t#Using Fig.10.2 on page no. 408\n", + "F63 = 0.04;\t \t\t#Using Fig.10.2 on page no. 408\n", + "F12 = 0.052;\t\t\t#Shape factor\n", + "F1w = (1-F12);\t\t\t#Shape factor between the floor and all the walls but the window\n", + "Q12 = (A*F12*5.67*10**-8*((Th+273)**4-(Tb+273)**4));\t\t\t#Heat exchange between the floor and window in W\n", + "#Q1 = (5.67*10**-8*A*((Th+273.15)**4-((F12*(Th+273.15)**4)-(F1w*(Tb+273.15)**4))))/1000;\t\t\t#Net heat given up by the floor in kW\n", + "Q1 = (5.67*10**-8*A*((Th+273)**4-((F12*(Th+273)**4)-(F1w*(294)**4))))/1000;\t\t\t#Net heat given up by the floor in kW\n", + "\n", + "\n", + "# Results\n", + "print 'Heat exchange between the floor and window is %3.0f W \\n \\\n", + "Net heat given up by the floor is %3.1f kW'%(Q12,Q1)\n", + "\n", + "\n", + "# Note : rounding off error." + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Heat exchange between the floor and window is 1283 W \n", + " Net heat given up by the floor is 110.1 kW\n" + ] + } + ], + "prompt_number": 4 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 10.14 Page No : 424" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "A2 = (6.*2);\t\t\t#Area of windows in m**2\n", + "A1 = (10.*12);\t\t\t#Area of floor in m**2\n", + "Th = 40.;\t\t\t#Radiating heating panel in degree C\n", + "Tb = 5.;\t\t\t#Temperature of black plane in degree C\n", + "F12 = 0.052;\t\t\t#Shape factor\n", + "\n", + "# Calculations\n", + "F12a = ((A2-(A1*F12**2))/(A1+A2-(2*A1*F12)));\t\t\t#Shape factor\n", + "Q12 = (A1*F12a*5.67*10**-8*((Th+273)**4-(Tb+273)**4));\t\t\t#Net heat exchange in W\n", + "X = (((A2/A1)-F12)/(1-F12));\t\t\t#X value for equilibrium temperature\n", + "T = (((Th+273)**4+(X*(Tb+273)**4))/(X+1))**0.25;\t\t\t#Equilibrium temperature in K\n", + "\n", + "# Results\n", + "print 'Net heat exchange is %3.0f W Equilibrium temperature is %3.2f K'%(Q12,T)\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Net heat exchange is 2409 W Equilibrium temperature is 311.57 K\n" + ] + } + ], + "prompt_number": 5 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 10.15 Page No : 430" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "D = 0.2;\t\t\t #Diameter of each disc in m\n", + "L = 2;\t\t\t #Distance between the plates in m\n", + "T = 800+273,300+273;\t\t\t#Temperatures of the plates in K\n", + "e = [0.3,0.5] ;\t\t\t#Emissivities of plates\n", + "\n", + "# Calculations\n", + "e1 = (e[0]*e[1]);\t\t\t#Equivalent emissivity\n", + "R = (D/L);\t\t\t#Ratio between diameter and distance between the plates\n", + "F = 0.014;\t\t\t#F value from Fig.10.4 from page no. 409\n", + "Q = (e1*(3.14/4)*D**2*F*5.67*10**-8*((T[0]**4-(T[1]**4))));\t\t\t#Radiant heat exchange for the plates in W\n", + "\n", + "# Results\n", + "print 'Radiant heat exchange for the plates is %3.2f W'%(Q)\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Radiant heat exchange for the plates is 4.55 W\n" + ] + } + ], + "prompt_number": 8 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 10.16 Page No : 430" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "e = 0.8;\t\t\t#Emissivity of brick wall\n", + "D1 = [6,4];\t\t\t#Width and Height in m\n", + "L = 0.04;\t\t\t#Distance from the wall in m\n", + "D2 = [0.2,0.2];\t\t\t#Dimensions of the furnace wall in m\n", + "D3 = [1,1];\t\t\t#Dimensions at lower and left of the centre of the wall in m\n", + "T = [1523+273,37+273];\t\t\t#Furnace temperature and wall temperature in degree C\n", + "\n", + "# Calculations\n", + "F12 = 0.033;\t\t\t#Shape factor from Fig.10.3 on page no. 409\n", + "F13 = 0.05;\t\t\t#Shape factor from Fig.10.3 on page no. 409\n", + "F14 = 0.12;\t\t\t#Shape factor from Fig.10.3 on page no. 409\n", + "F15 = 0.08;\t\t\t#Shape factor from Fig.10.3 on page no. 409\n", + "Fow = (F12+F13+F14+F15);\t\t\t#Shape factor between opening and wall\n", + "Q = (e*L*Fow*5.67*10**-8*(T[0]**4-T[1]**4))/1000;\t\t\t#Net radiation exchange in kW\n", + "\n", + "# Results\n", + "print 'Net radiation exchange between the opening and the wall is %3.1f kW'%(Q)\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Net radiation exchange between the opening and the wall is 5.3 kW\n" + ] + } + ], + "prompt_number": 9 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 10.17 Page No : 431" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "D = [2,1,1];\t\t\t#Dimensions of the math.tank in m\n", + "A = 8;\t\t\t#Area of the tank in m**2\n", + "e = 0.9;\t\t\t#Surface emissivity \n", + "Ts = 25+273;\t\t\t#Surface temperature in K\n", + "Ta = 2+273;\t\t\t#Ambient temperature in K\n", + "e1 = 0.5;\t\t\t#Emissivity of aluminium \n", + "\n", + "# Calculations\n", + "Q = (e*A*5.67*10**-8*(Ts**4-Ta**4))/1000;\t\t\t#Heat lost by radiation in kW\n", + "r = ((e-e1)/e)*Q;\t\t\t#Reduction in heat loss if the tank is coated with an aluminium paint in kW\n", + "\n", + "# Results\n", + "print 'Heat lost by radiation is %3.2f kW \\n \\\n", + "Reduction in heat loss if the tank is coated with an aluminium paint is %3.3f kW'%(Q,r)\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Heat lost by radiation is 0.88 kW \n", + " Reduction in heat loss if the tank is coated with an aluminium paint is 0.393 kW\n" + ] + } + ], + "prompt_number": 10 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 10.18 Page No : 432" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "D = 0.2;\t\t\t#Outer diameter of the pipe in m\n", + "Ta = 30+273;\t\t\t#Temperature of the air in K\n", + "Ts = 400+273;\t\t\t#Surface temperature in K\n", + "e = 0.8;\t\t\t#Emissivity of the pipe surface\n", + "D1 = 0.4;\t\t\t#Diamter of brick in m\n", + "e1 = 0.91;\t\t\t#Emissivity of brick\n", + "\n", + "# Calculations\n", + "Q = (e*3.14*D*5.67*10**-8*(Ts**4-Ta**4))/1000;\t\t\t#Loss of heat by thermal radiation in kW/m\n", + "e2 = (1./((1./e)+((D/D1)*((1./e1)-1))));\t\t\t#Equivalent emissivity\n", + "Q1 = (e2*3.14*D*5.67*10**-8*(Ts**4-Ta**4))/1000;\t\t\t#Heat loss when brick is used in kW/m\n", + "r = (round(Q,2)-round(Q1,2))*1000;\t\t\t#Reduction in heat loss in W/m\n", + "\n", + "# Results\n", + "print 'Loss of heat by thermal radiation is %3.1f*10**3 W/m \\n \\\n", + "Reduction in heat loss is %3.0f W/m'%(Q,r)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Loss of heat by thermal radiation is 5.6*10**3 W/m \n", + " Reduction in heat loss is 210 W/m\n" + ] + } + ], + "prompt_number": 5 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 10.19 Page No : 433" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "e = 0.03;\t\t\t#Emissivity of silver\n", + "T2 = -153.+273;\t\t\t#Temperature of the outer surface of the inner wall in K\n", + "T1 = 27.+273;\t\t\t#Temperature of the inner surface of the outer wall in K\n", + "D1 = 0.42;\t\t\t#Diamter of first sphere in m\n", + "D2 = 0.6;\t\t\t#Diamter of the second sphere in m\n", + "V = 220.;\t\t\t#Rate of vapourization in kJ/kg\n", + "\n", + "# Calculations\n", + "e1 = (1./((1./e)+((D1/D2)**2*((1./e)-1))));\t\t\t#Equivalent emissivity\n", + "A = (4*3.14*(D1/2)**2);\t\t\t#Area in m**2\n", + "Q = (e1*A*5.67*10**-8*(T1**4-T2**4))/(1000./3600);\t\t\t#Radiation heat transfer through walls into the vessel in kJ/h\n", + "R = (Q/V);\t\t\t#Rate of evaporation in kg/h\n", + "\n", + "# Results\n", + "print 'Radiation heat transfer through walls into the vessel is %3.3f kJ/h \\n \\\n", + "Rate of evaporation of liqiud oxygen is %3.4f kg/h'%(Q,R)\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Radiation heat transfer through walls into the vessel is 18.146 kJ/h \n", + " Rate of evaporation of liqiud oxygen is 0.0825 kg/h\n" + ] + } + ], + "prompt_number": 16 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 10.20 Page No : 433" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "T = [800+273,300+273];\t\t\t#Temperatures of the plates in K\n", + "e = [0.3,0.5];\t\t\t#Emissivities of the plates\n", + "\n", + "# Calculations\n", + "Q = ((5.67*10**-8*(T[0]**4-T[1]**4))/((1./e[0])+((1./e[1]))-1))/1000;\t\t\t#Net radiant heat exchange in kW/m**2\n", + "\n", + "# Results\n", + "print 'Net radiant heat exchange is %3.2f kW/m**2'%(Q)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Net radiant heat exchange is 15.93 kW/m**2\n" + ] + } + ], + "prompt_number": 17 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 10.21 Page No : 434" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "T1 = 127+273;\t\t\t#Temperature of the outer side of the brick setting in K\n", + "T2 = 50+273;\t\t\t#Temperature of the inside of the steel plate in K\n", + "e1 = 0.6;\t\t\t#Emissivity of steel\n", + "e2 = 0.8;\t\t\t#Emissivity of fireclay\n", + "\n", + "# Calculations\n", + "Q = ((5.67*10**-8*(T1**4-T2**4))/((1./e1)+((1./e2))-1));\t\t\t#Net radiant heat exchange in W/m**2\n", + "\n", + "# Results\n", + "print 'Net radiant heat exchange is %3.0f W/m**2'%(Q)\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Net radiant heat exchange is 435 W/m**2\n" + ] + } + ], + "prompt_number": 18 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 10.22 Page No : 445" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "D = 1;\t\t\t#Dimension of the plate in m\n", + "L = 0.5;\t\t\t#Distance between the plates in m\n", + "Ts = 27+273;\t\t\t#Surface temperature of the walls in K\n", + "T = [900+273,400+273];\t\t\t#Temperature of the plates in K\n", + "e = [0.2,0.5];\t\t\t#Emissivities of the plates \n", + "\n", + "# Calculations\n", + "F12 = 0.415;\t\t\t#From Fig.10.4 on page no.409\n", + "F13 = (1-F12);\t\t\t#Shape factor\n", + "F23 = (1-F12);\t\t\t#Shape factor\n", + "R1 = (1-e[0])/(e[0]*D*D);\t\t\t#Resistance for 1\n", + "R2 = (1-e[1])/(e[1]*D*D);\t\t\t#Resistance for 2\n", + "R3 = 0;\t\t\t #Resistance for 3\n", + "A1F12I = (1./(D*D*F12));\t\t\t#Inverse of the product of area and Shape factor\n", + "A1F13I = (1./(D*D*F13));\t\t\t#Inverse of the product of area and Shape factor\n", + "A2F23I = (1./(D*D*F23));\t\t\t#Inverse of the product of area and Shape factor\n", + "Eb1 = (5.67*10**-8*T[0]**4)/1000;\t\t\t#Emissive power of 1 in kW/m**2\n", + "Eb2 = (5.67*10**-8*T[1]**4)/1000;\t\t\t#Emissive power of 2 in kW/m**2\n", + "Eb3 = (5.67*10**-8*Ts**4);\t\t\t#Emissive power of 3 in W/m**2\n", + "J1 = 25;\t\t\t#Radiosity at node 1 in kW/m**2\n", + "J2 = 11.53;\t\t\t#Radiosity at node 2 in kW/m**2\n", + "J3 = 0.46;\t\t\t#Radiosity at node 3 in kW/m**2\n", + "Q1 = ((Eb1-J1)/R1);\t\t\t#Total heat loss by plate 1 in kW\n", + "Q2 = ((Eb2-J2)/R2);\t\t\t#Total heat loss by plate 2 in kW\n", + "Q3 = ((J1-J3)/(A1F13I))+((J2-J3)/(A2F23I));\t\t\t#Total heat received by the room in kW\n", + "\n", + "# Results\n", + "print 'Total heat loss by plate 1 is %3.1f kW Total heat loss by plate 2 is %3.1f kW \\n \\\n", + "Total heat received by the room is %3.2f kW'%(Q1,Q2,Q3)\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Total heat loss by plate 1 is 20.6 kW Total heat loss by plate 2 is 0.1 kW \n", + " Total heat received by the room is 20.83 kW\n" + ] + } + ], + "prompt_number": 19 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 10.23 Page No : 447" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "T = [800+273,300+273];\t\t\t#Temperatures of the plates in K\n", + "e = [0.3,0.5];\t\t\t#Emissivities of the plates\n", + "e3 = 0.05;\t\t\t#Emissivity of aluminium\n", + "\n", + "# Calculations\n", + "q = ((5.67*10**-8*(T[0]**4-T[1]**4))/((1./e[0])+(1./e[1])-1))/1000;\t\t\t#Heat transfer without the shield in kW/m**2\n", + "R1 = (1-e[0])/e[0];\t\t\t#Resistance in 1\n", + "R2 = (1-e[1])/e[1];\t\t\t#Resistance in 2\n", + "R3 = (1-e3)/e3;\t\t\t#Resistance in 3\n", + "R = (R1+(2*R2)+(2*R3));\t\t\t#Total resismath.tance \n", + "q1 = ((5.67*10**-8*(T[0]**4-T[1]**4))/R)/1000;\t\t\t#Heat transfer with shield in kW/m**2\n", + "r = ((q-q1)*100)/q;\t\t\t#Reduction in heat transfer \n", + "X1 = ((1./e3)+(1./e[1])-1);\t\t\t#X1 for tempearture T3\n", + "X2 = ((1./e[0])+(1./e3)-1);\t\t\t#X1 for tempearture T3\n", + "T3 = (((X1*T[0]**4)+(X2*T[1]**4))/(X2+X1))**0.25;\t\t\t#Temperature of the sheild in K\n", + "T3c = T3-273;\t\t\t#Temperature of the sheild in degree C\n", + "\n", + "# Results\n", + "print 'Percentage reduction in heat transfer is %3.0f percent \\n \\\n", + "Temperature of the sheild is %3.2f degree C'%(r,T3c)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Percentage reduction in heat transfer is 90 percent \n", + " Temperature of the sheild is 641.02 degree C\n" + ] + } + ], + "prompt_number": 20 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 10.24 Page No : 448" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "Q = 79;\t\t\t#Reduction in net radiation from the surfaces \n", + "e1 = 0.05;\t\t\t#Emissivity of the screen\n", + "e2 = 0.8;\t\t\t#Emissivity of the surface\n", + "\n", + "# Calculations\n", + "n = (((Q*((2/e2)-1))-((2/e2)+1))/((2/e1)-1));\t\t\t#Number of screens to be placed between the two surfaces to achieve the reduction in heat exchange\n", + "\n", + "# Results\n", + "print 'Number of screens to be placed between the two surfaces to achieve the reduction in heat exchange is%3.0f'%(n)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Number of screens to be placed between the two surfaces to achieve the reduction in heat exchange is 3\n" + ] + } + ], + "prompt_number": 21 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 10.25 Page No : 449" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "e = 0.8;\t\t\t#Emissivity of the pipe\n", + "D = 0.275;\t\t\t#Diameter of the pipe in m\n", + "Ts = 500+273;\t\t\t#Surface temperature in K\n", + "Te = 30+273;\t\t\t#Temperature of enclosure in K\n", + "D1 = 0.325;\t\t\t#Diamter of the steel screen in m\n", + "e1 = 0.7;\t\t\t#Emissivity of steel screen\n", + "Tsc = 240+273;\t\t\t#Temperature of screen in K\n", + "\n", + "#CALCUATIONS\n", + "Q = (e*5.67*10**-8*3.14*D*(Ts**4-Te**4))/1000;\t\t\t#Loss of heat per unit length by radiation in kW/m\n", + "e2 = (1./((1./e)+((D/D1)*((1./e1)-1))));\t\t\t#Equivalent emissivity\n", + "Q1 = (e2*5.67*10**-8*3.14*D*(Ts**4-Tsc**4))/1000;\t\t\t#Radiant heat exchange per unit length of header with screen in kW/m\n", + "R = (Q-Q1);\t\t\t#Reduction in heat by radiation due to the provision of the screen in kW/m\n", + "\n", + "# Results\n", + "print 'Loss of heat per unit length by radiation is %3.1f kW/m \\n \\\n", + "Reduction in heat by radiation due to the provision of the screen is %3.2f kW/m'%(Q,R)\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Loss of heat per unit length by radiation is 13.7 kW/m \n", + " Reduction in heat by radiation due to the provision of the screen is 4.92 kW/m\n" + ] + } + ], + "prompt_number": 22 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 10.26 Page No : 451" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "e = 0.6;\t\t \t#Emissivity of thermocouple\n", + "Ta = 20+273;\t\t\t#Ambient temperature in K\n", + "Tt = 500+273;\t\t\t#Temperature from the thermocouple in K\n", + "e = 0.3;\t \t\t#Emissivity of radiation shield\n", + "h = 200;\t\t \t#Convective heat transfer coefficient in W/m**2.K\n", + "Ts = 833;\t\t\t #Temperature in K\n", + "\n", + "# Calculations\n", + "T = ((5.67*10**-8*e*(Tt**4-Ta**4))/(h*1000))+Tt;\t\t\t#Temperature of the shield in K\n", + "T1 = (Ts-T);\t\t\t#Error between the thermocouple temperature and gas temperature in K\n", + "Ts = 825.; \t\t\t#Surface temperature with radiation shield in K\n", + "Tc = 829.;\t \t\t#Thermocouple temperature with radiation shield in K\n", + "e = (Tc-Ts);\t\t\t#Error between the thermocouple temperature and gas temperature with the shielded thermocouple arrangement in K\n", + "\n", + "# Results\n", + "print 'Error between the thermocouple temperature and gas temperature is%3.0f K \\n \\\n", + "Error between the thermocouple temperature and gas temperature with the shielded thermocouple arrangement is%3.0f K'%(T1,e)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Error between the thermocouple temperature and gas temperature is 60 K \n", + " Error between the thermocouple temperature and gas temperature with the shielded thermocouple arrangement is 4 K\n" + ] + } + ], + "prompt_number": 23 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 10.27 Page No : 452" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "D = 0.2;\t\t\t#Diameter of pipe in m\n", + "Ta = 30+273;\t\t\t#Temperature of air in K\n", + "Ts = 200+273;\t\t\t#Temperature of surface in K\n", + "e = 0.8;\t\t\t#Emissivity of the pipe\n", + "\n", + "# Calculations\n", + "Q = (e*5.67*10**-8*3.14*D*(Ts**4-Ta**4));\t\t\t#Heat lost by thermal radiation in W/m\n", + "T = (Ta+Ts)/2;\t\t\t#Film temperature in degree C\n", + "k = 0.03306;\t\t\t#Thermal conductivity in W/m.K\n", + "v1 = (24.93*10**-6);\t\t\t#Kinematic viscosity in m**2/s\n", + "b = (1./388);\t\t\t#Coefficient of thermal expansion in 1./K\n", + "Pr = 0.687;\t\t\t#Prantl number\n", + "Ra = ((9.81*b*D**3*(Ts-Ta)*Pr)/(v1**2));\t\t\t#Rayleigh number\n", + "Nu = (0.53*(Ra)**0.25);\t\t\t#Nussults number\n", + "h = (k*Nu)/D;\t\t\t#Heat transfer coefficient in W/m**2.K\n", + "Q1 = (h*3.14*D*(Ts-Ta));\t\t\t#Heat lost by convection in W/m\n", + "Q2 = (Q+Q1);\t\t\t#Total heat lost per meter length in W/m\n", + "\n", + "# Results\n", + "print 'Heat lost by thermal radiation is %3.0f W/m \\n \\\n", + "Heat lost by convection is %3.1f W/m'%(Q,Q1)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Heat lost by thermal radiation is 1186 W/m \n", + " Heat lost by convection is 734.4 W/m\n" + ] + } + ], + "prompt_number": 24 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 10.28 Page No : 453" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "Ts = 200+273;\t\t\t#Temperature of stream main in K\n", + "Ta = 30+273;\t\t\t#Rooom temperature in K\n", + "h = 17.98;\t\t\t#Heat transfer coefficient in W/m**2.K\n", + "e = 0.8;\t\t\t#Emissivity of the pipe surface\n", + "\n", + "# Calculations\n", + "q = (5.67*10**-8*e*(Ts**4-Ta**4));\t\t\t#Heat transfer by radiation in W/m**2\n", + "hr = (q/(Ts-Ta));\t\t\t #Heat transfer coefficient due to radiation in W/m**2.K\n", + "hc = (h-hr);\t\t\t #Heat transfer coefficient due to convection in W/m**2.K\n", + "\n", + "# Results\n", + "print 'Heat transfer coefficient due to radiation is %3.1f W/m**2.K \\n \\\n", + "Heat transfer coefficient due to convection is %3.2f W/m**2.K'%(hr,hc)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Heat transfer coefficient due to radiation is 11.1 W/m**2.K \n", + " Heat transfer coefficient due to convection is 6.87 W/m**2.K\n" + ] + } + ], + "prompt_number": 25 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 10.29 Page No : 461" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math\n", + "# Variables\n", + "t = 0.05;\t\t\t#Thickness of the gas layer in m\n", + "r = 0.1;\t\t\t#Remaining radiation intensity\n", + "\n", + "# Calculations\n", + "a = (-1./t)*2.3*(math.log(r)/math.log(10));\t\t\t#Extinction coefficient per m\n", + "\n", + "# Results\n", + "print 'Extinction coefficient is %3.2f/m'%(a)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Extinction coefficient is 46.00/m\n" + ] + } + ], + "prompt_number": 26 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 10.30 Page No : 462" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "A = 30.;\t\t\t#Total surface area in m**2\n", + "V = 10.;\t\t\t#Volume in m**3\n", + "Ts = 1000.;\t\t\t#Temperature of the furnace in degree C\n", + "p = 2.; \t\t\t#Total pressure in atm\n", + "ph2o = 0.1;\t\t\t#Partial pressure of water vapour in atm\n", + "pco2 = 0.3;\t\t\t#Partial pressure of CO2\n", + "\n", + "# Calculations\n", + "lms = (3.6*V)/A;\t\t\t#Mean beam length in m\n", + "pco2lms = (pco2*lms);\t\t\t#pco2lms in m.atm\n", + "eco2 = 0.16;\t\t\t#From Fig.10.23 on page no. 458\n", + "cco2 = 1.11;\t\t\t#From Fig.10.23 on page no. 458\n", + "cco2eco2 = (cco2*eco2);\t\t\t#cco2eco2 value\n", + "ph2olms = (ph2o*lms);\t\t\t#ph2olms in m.atm\n", + "eh2o = 0.12;\t\t\t#From Fig.10.24 on page no. 459\n", + "P = (p+ph2o)/2;\t\t\t#P value in atm\n", + "ch2o = 1.43;\t\t\t#From Fig.10.26 on page no. 460\n", + "ch2oeh2o = (ch2o*eh2o);\t\t\t#ch2oeh2o value\n", + "P1 = (ph2o/(ph2o+pco2));\t\t\t#Ratio of pressures\n", + "X = (pco2lms+ph2olms);\t\t\t#X value in m.atm\n", + "e = 0.035;\t\t\t#Error value from Fig. 10.27 on page no.461\n", + "et = (cco2eco2+ch2oeh2o-e);\t\t\t#Total emissivity of the gaseous mixture \n", + "\n", + "# Results\n", + "print 'Emissivity of the gaseous mixture is %3.4f'%(et)" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Emissivity of the gaseous mixture is 0.3142\n" + ] + } + ], + "prompt_number": 27 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 10.31 Page No : 463" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "Tg = 950+273;\t\t\t#Flue gas temperature in K\n", + "p = 1;\t\t\t#Total pressure in atm\n", + "pco2 = 0.1;\t\t\t#Percent of co2\n", + "ph2o = 0.04;\t\t\t#Percent of h2o\n", + "D = 0.044;\t\t\t#Diameter of the tube in m\n", + "e = 0.8;\t\t\t#Emissivity of grey surface \n", + "Tw = 500+273.;\t\t\t#Uniform temperature in K\n", + "\n", + "# Calculations\n", + "lms = (3*0.044);\t\t\t#lms value from Table 10.2 on page no. 457\n", + "pco2lms = (pco2*lms);\t\t\t#pco2lms in m.atm\n", + "ph2olms = (ph2o*lms);\t\t\t#ph2olms in m.atm\n", + "eco2 = 0.05;\t\t\t#From Fig.10.23 on page no. 458\n", + "eh2o = 0.005;\t\t\t#From Fig.10.24 on page no. 459\n", + "b = 1.05;\t\t\t#Correction factor from Fig. 10.28 on page no. 461\n", + "eg = 0.061;\t\t\t#Total emissivity of gaseous mixture\n", + "ag = ((0.056*(Tg/Tw)**0.65)+(b*0.021));\t\t\t#Absorbtivity of the gases \n", + "q = (0.5*(e+1)*5.67*10**-8*((eg*Tg**4)-(ag*Tw**4)));\t\t\t#Heat transfer rate by radiation in W/m**2\n", + "hr = (q/(Tg-Tw));\t\t\t#Radiation heat transfer coefficient in W/m**2.degree C\n", + "\n", + "# Results\n", + "print 'Net radiation exchange between the gas and the tube walls is %3.0f W/m**2 \\n \\\n", + "Radiation heat transfer coefficient is %3.2f W/m**2.degree C'%(q,hr)\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Net radiation exchange between the gas and the tube walls is 5187 W/m**2 \n", + " Radiation heat transfer coefficient is 11.53 W/m**2.degree C\n" + ] + } + ], + "prompt_number": 6 + } + ], + "metadata": {} + } + ] +}
\ No newline at end of file diff --git a/Fundamentals_Of_Engineering_Heat_And_Mass_Transfer/ch11.ipynb b/Fundamentals_Of_Engineering_Heat_And_Mass_Transfer/ch11.ipynb new file mode 100755 index 00000000..b7e9b3c7 --- /dev/null +++ b/Fundamentals_Of_Engineering_Heat_And_Mass_Transfer/ch11.ipynb @@ -0,0 +1,486 @@ +{ + "metadata": { + "name": "", + "signature": "sha256:a7f87932a4eea8107911ad53ff496ae266946836f956d53145d3e7186e5c88d6" + }, + "nbformat": 3, + "nbformat_minor": 0, + "worksheets": [ + { + "cells": [ + { + "cell_type": "heading", + "level": 1, + "metadata": {}, + "source": [ + "Chapter 11 : Boiling and Condensation" + ] + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 11.1 Page No : 480" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math \n", + "\n", + "# Variables\n", + "Tsat = 100.;\t\t\t#Saturation temperature of water in degree C\n", + "p1 = 957.9;\t\t\t#Density of liquid in kg/m**3\n", + "Cpl = 4217.;\t\t\t#Specific heat in J/kg.K\n", + "u = (279.*10**-6);\t\t\t#Dynamic viscosity in N.s/m**2\n", + "Pr = 1.76;\t\t\t#Prantl number\n", + "hjg = 2257.;\t\t\t#Enthalpy in kJ/kg\n", + "s = (58.9*10**-3);\t\t\t#Surface tension in N/m\n", + "pv = 0.5955;\t\t\t#Density of vapour in kg/m**3\n", + "m = 30.;\t\t\t#Rate of water in kg/h\n", + "D = 0.3;\t\t\t#Diameter in m\n", + "\n", + "# Calculations\n", + "q = round((m*hjg*1000)/(3600*math.pi*D**2/4));\t\t\t#Heat transfer in W/m**2\n", + "Ts = Tsat+(((q/(u*hjg*1000))*math.sqrt(s/(9.81*(p1-pv)))))**0.33\n", + "\n", + "# Results\n", + "print 'Temperature of the bottom surface of the pan is %3.2f degree C'%(Ts)\n", + "\n", + "# NOte: answer in book is wrong." + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Temperature of the bottom surface of the pan is 101.02 degree C\n" + ] + } + ], + "prompt_number": 7 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 11.2 Page No : 481" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "Tsat = 100;\t\t\t#Saturation temperature of water in degree C\n", + "p1 = 957.9;\t\t\t#Density of liquid in kg/m**3\n", + "Cpl = 4217;\t\t\t#Specific heat in J/kg.K\n", + "u = (279*10**-6);\t\t\t#Dynamic vismath.cosity in N.s/m**2\n", + "Pr = 1.76;\t\t\t#Prantl number\n", + "hjg = 2257;\t\t\t#Enthalpy in kJ/kg\n", + "s = (58.9*10**-3);\t\t\t#Surface tension in N/m\n", + "pv = 0.5955;\t\t\t#Density of vapour in kg/m**3\n", + "m = 30;\t\t\t#Rate of water in kg/h\n", + "D = 0.3;\t\t\t#Diameter in m\n", + "\n", + "# Calculations\n", + "q = (0.18*hjg*1000*pv*((s*9.81*(p1-pv))/pv**2)**0.25)/10**6;\t\t\t#Burnout heat flux in MW/m**2\n", + "\n", + "# Results\n", + "print 'Burnout heat flux is %3.3f MW/m**2'%(q)\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Burnout heat flux is 1.520 MW/m**2\n" + ] + } + ], + "prompt_number": 2 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 11.3 Page No : 481" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "D = 0.0016;\t\t\t#Diameter of the wire in m\n", + "T = 255;\t\t\t#Temperature difference in degree C\n", + "p1 = 957.9;\t\t\t#Density of liquid in kg/m**3\n", + "Cpl = 4640;\t\t\t#Specific heat in J/kg.K\n", + "u = (18.6*10**-6);\t\t\t#Dynamic viscosity in N.s/m**2\n", + "hjg = 2257;\t\t\t#Enthalpy in kJ/kg\n", + "k = (58.3*10**-3);\t\t\t#Thermal conductivity in W/m.K\n", + "pv = 31.54;\t\t\t#Density of vapour in kg/m**3\n", + "Ts = 628;\t\t\t#Surface temperature in K\n", + "Tsat = 373;\t\t\t#Saturation temperature in K\n", + "\n", + "# Calculations\n", + "hc = (0.62*((k**3*pv*(p1-pv)*9.81*((hjg*1000)+(0.4*Cpl*T)))/(u*D*T))**0.25);\t\t\t#Convective heat transfer coefficient in W/m**2.K\n", + "hr = ((5.67*10**-8)*(Ts**4-Tsat**4))/(Ts-Tsat);\t\t\t#Radiative heat transfer coefficient in W/m**2.K\n", + "hm = (hc+(0.75*hr));\t\t\t#Mean heat transfer coefficient in W/m**2.K\n", + "Q = (hm*3.14*D*T)/1000;\t\t\t#Power dissipation rate per unit length of the heater in kW/m\n", + "\n", + "# Results\n", + "print 'Mean heat transfer coefficient is %3.1f W/m**2.K \\n \\\n", + "Power dissipation rate per unit length of the heater is %3.3f kW/m'%(hm,Q)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Mean heat transfer coefficient is 1340.9 W/m**2.K \n", + " Power dissipation rate per unit length of the heater is 1.718 kW/m\n" + ] + } + ], + "prompt_number": 3 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 11.4 Page No : 485" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "Ts = 10.;\t\t\t#Surface temperature in degree C\n", + "p1 = 10.;\t\t\t#Pressure of water in atm\n", + "\n", + "# Calculations\n", + "hp = (5.56*Ts**0.4);\t\t\t#Heat transfer coefficient in kW/m**2.K\n", + "hp1 = (5.56*(2*Ts)**3*p1**0.4);\t\t\t#Heat transfer coefficient in kW/m**2.K\n", + "hp2 = (5.56*Ts**3*(2*p1)**0.4);\t\t\t#Heat transfer coefficient in kW/m**2.K\n", + "x1 = (hp1/hp)/1000;\t\t\t#Ratio of heat transfer coefficients\n", + "x2 = (hp2/hp)*100;\t\t\t#Ratio of heat transfer coefficients\n", + "\n", + "# Results\n", + "print 'Heat transfer coefficient becomes %.f times the original value in the first case\\n \\\n", + "Heat transfer coefficient is increased only by 32 percent in the second case'%(x1)\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Heat transfer coefficient becomes 8 times the original value in the first case\n", + " Heat transfer coefficient is increased only by 32 percent in the second case\n" + ] + } + ], + "prompt_number": 3 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 11.5 Page No : 485" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math\n", + "\n", + "# Variables\n", + "p = 6.;\t\t\t#Pressure of water in atm\n", + "D = 0.02;\t\t\t#Diameter of the tube in m\n", + "Ts = 10.;\t\t\t#Wall temperature in degree C\n", + "L = 1.;\t\t\t#Length of the tube in m\n", + "\n", + "# Calculations\n", + "p1 = (p*1.0132*10**5)/10**6;\t\t\t#Pressure in MN/m**2\n", + "h = (2.54*Ts**3*math.exp(p1/1.551));\t\t\t#Heat transfer coefficient in W/m**2.K\n", + "Q = (h*math.pi*D*L*Ts);\t\t\t#Heat transfer rate in W/m\n", + "\n", + "\n", + "# Results\n", + "print 'Heat transfer rate is %3.1f W/m'%(Q)\n", + "\n", + "\n", + "# note : rounding off error." + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Heat transfer rate is 2361.8 W/m\n" + ] + } + ], + "prompt_number": 13 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 11.6 Page No : 489" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "p = 2.45;\t\t\t#Pressure of dry saturated steam in bar\n", + "h = 1;\t\t\t#Height of vertical tube in m\n", + "Ts = 117;\t\t\t#Tube surface temperature in degree C\n", + "d = 0.2;\t\t\t#Distance from upper end of the tube in m\n", + "\n", + "# Calculations\n", + "Tsat = 127;\t\t\t#Saturation temperature of water in degree C\n", + "p1 = 941.6;\t\t\t#Density of liquid in kg/m**3\n", + "k1 = 0.687;\t\t\t#Thermal conductivity in W/m.K\n", + "u = (227*10**-6);\t\t\t#Dynamic vismath.cosity in N.s/m**2\n", + "hfg = 2183;\t\t\t#Enthalpy in kJ/kg\n", + "pv = 1.368;\t\t\t#Density of vapour in kg/m**3\n", + "q = round((((4*k1*u*10*d)/(9.81*p1*(p1-pv)*hfg*1000))**0.25)*1000,2);\t\t\t#Thickness of condensate film in mm\n", + "h = (k1/(q/1000));\t\t\t#Local heat transfer coefficient at x = 0.2 in W/m**2.K\n", + "\n", + "# Results\n", + "print 'Thickness of condensate film is %3.2f mm \\n \\\n", + "Local heat transfer coefficient at x = 0.2 is %3.0f W/m**2.K'%(q,h)\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Thickness of condensate film is 0.09 mm \n", + " Local heat transfer coefficient at x = 0.2 is 7633 W/m**2.K\n" + ] + } + ], + "prompt_number": 17 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 11.7 Page No : 491" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math\n", + "\n", + "# Variables\n", + "D = 0.05;\t\t\t#Diameter of the tube in m\n", + "L = 2;\t\t\t#Length of the tube in m\n", + "Ts = 84;\t\t\t#Outer surface temperature in degree C\n", + "Tsat = 100;\t\t\t#Saturation temperature of water in degree C\n", + "Tf = (Tsat+Ts)/2;\t\t\t#Film temperature in degree C\n", + "p1 = 963.4;\t\t\t#Density of liquid in kg/m**3\n", + "u = (306*10**-6);\t\t\t#Dynamic vismath.cosity in N.s/m**2\n", + "hfg = 2257;\t\t\t#Enthalpy in kJ/kg\n", + "pv = 0.596;\t\t\t#Density of vapour in kg/m**3\n", + "k1 = 0.677;\t\t\t#Thermal conductivity in W/m.K\n", + "\n", + "# Calculations\n", + "hL = (1.13*((9.81*p1*(p1-pv)*k1**3*hfg*1000)/(u*16*L))**0.25);\t\t\t#Heat transfer coefficient in W/m**2.K\n", + "Ref = ((4*hL*L*2)/(hfg*1000*u));\t\t\t#Reynolds nmber\n", + "Q = (hL*math.pi*D*L*10);\t\t\t#Heat transfer rate in W\n", + "m = (Q/(hfg*1000))*3600;\t\t\t#Condensate mass flow rate in kg/h\n", + "\n", + "# Results\n", + "print 'Heat transfer rate is %3.0f W \\n \\\n", + "Condensate mass flow rate is %3.1f kg/h'%(Q,m)\n", + "\n", + "# note : rounding off error." + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Heat transfer rate is 17930 W \n", + " Condensate mass flow rate is 28.6 kg/h\n" + ] + } + ], + "prompt_number": 21 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 11.8 Page No : 492" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "h = 2.8;\t\t\t#Height of the plate in m\n", + "T = 54.;\t\t\t#Temperature of the plate in degree C\n", + "Tsat = 100.;\t\t\t#Saturation temperature of water in degree C\n", + "Tf = (Tsat+T)/2;\t\t\t#Film temperature in degree C\n", + "p1 = 973.7;\t\t\t#Density of liquid in kg/m**3\n", + "u = (365.*10**-6);\t\t\t#Dynamic viscosity in N.s/m**2\n", + "hfg = 2257.;\t\t\t#Enthalpy in kJ/kg\n", + "pv = 0.596;\t\t\t#Density of vapour in kg/m**3\n", + "k1 = 0.668;\t\t\t#Thermal conductivity in W/m.K\n", + "\n", + "# Calculations\n", + "Re = (0.00296*((p1*9.81*(p1-pv)*k1**3*(Tsat-T)**3*h**3)/(u**5*(hfg*1000)**3))**(5./9));\t\t\t#Reynolds number\n", + "hL = (0.0077*((9.81*p1*(p1-pv)*k1**3)/u**2)**(1./3)*Re**0.4);\t\t\t#Heat transfer coefficient in W/m**2.K\n", + "Q = (hL*h*(Tsat-T))/1000;\t\t\t#Heat transfer rate per unit width in kW/m\n", + "\n", + "# Results\n", + "print 'Heat transfer rate per unit width is %3.2f kW/m'%(Q)\n", + "\n", + "\n", + "# note : rounding error." + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Heat transfer rate per unit width is 702.33 kW/m\n" + ] + } + ], + "prompt_number": 26 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 11.9 Page No : 494" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "T = 100;\t\t\t#Temperature of dry steam in degree C\n", + "Do = 0.025;\t\t\t#Outer diameter of the pipe in m\n", + "Ts = 84;\t\t\t#Surface temmperature of pipe in degree C\n", + "Tf = (T+Ts)/2;\t\t#Film temperature in degree C\n", + "p1 = 963.4;\t\t\t#Density of liquid in kg/m**3\n", + "u = (306*10**-6);\t#Dynamic viscosity in N.s/m**2\n", + "hfg = 2257;\t\t\t#Enthalpy in kJ/kg\n", + "pv = 0.596;\t\t\t#Density of vapour in kg/m**3\n", + "k1 = 0.677;\t\t\t#Thermal conductivity in W/m.K\n", + "\n", + "# Calculations\n", + "h = (0.725*((9.81*p1*(p1-pv)*k1**3*hfg*1000)/(u*(T-Ts)*Do))**0.25);\t\t\t#Heat transfer coefficient in W/m**2.K\n", + "q = (h*3.14*Do*(T-Ts))/1000;\t\t\t#Heat transfer per unit length in kW/m\n", + "m = (q/hfg)*3600;\t\t\t #Total mass flow of condensate per unit length in kg/h\n", + "\n", + "# Results\n", + "print 'Rate of formation of condensate per unit length is %3.2f kg/h'%(m)\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Rate of formation of condensate per unit length is 21.94 kg/h\n" + ] + } + ], + "prompt_number": 13 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 11.10 Page No : 494" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "m = 50;\t\t\t#Mass of vapour per hour\n", + "n = 100;\t\t\t#Number of tubes\n", + "D = 0.01;\t\t\t#Diameter of the tube in m\n", + "L = 1;\t\t\t#Length of the tube in m\n", + "n1 = 10;\t\t\t#Array of 10*10\n", + "\n", + "# Calculations\n", + "mr = ((0.725/1.13)*(L/(n1*D))**0.25);\t\t\t#Ratio of horizontal and vertical position \n", + "mv = (m/mr);\t\t\t#Mass flow rate in the vertical position in kg/h\n", + "\n", + "# Results\n", + "print 'Mass flow rate in the vertical position is %3.2f kg/h'%(mv)\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Mass flow rate in the vertical position is 43.82 kg/h\n" + ] + } + ], + "prompt_number": 14 + } + ], + "metadata": {} + } + ] +}
\ No newline at end of file diff --git a/Fundamentals_Of_Engineering_Heat_And_Mass_Transfer/ch12.ipynb b/Fundamentals_Of_Engineering_Heat_And_Mass_Transfer/ch12.ipynb new file mode 100755 index 00000000..eb722971 --- /dev/null +++ b/Fundamentals_Of_Engineering_Heat_And_Mass_Transfer/ch12.ipynb @@ -0,0 +1,923 @@ +{ + "metadata": { + "name": "", + "signature": "sha256:0803cdabadcb852bdbb9c79bc32fa04b5ddfc37dadc8bca5c47a13f22864faf2" + }, + "nbformat": 3, + "nbformat_minor": 0, + "worksheets": [ + { + "cells": [ + { + "cell_type": "heading", + "level": 1, + "metadata": {}, + "source": [ + "Chapter 12 : Heat Exchangers" + ] + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 12.1 Page No : 503" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math \n", + "\n", + "#INPUT\n", + "T = 80.;\t\t \t#Bulk Temperature of water in degrees C\n", + "Di = 0.0254;\t\t\t#Inner diameter of steel pipe in m\n", + "Do = 0.0288;\t\t\t#Outer diameter of steel pipe in m\n", + "k = 50.;\t\t\t #Thermal conductivity of steel in W/m.K\n", + "ho = 30800.;\t\t \t#Average convection coefficient in W/m**2.K\n", + "v = 0.50;\t\t \t#Velocity of water in m/s\n", + "# Variables FROM HEAT AND MASS TRANSFER DATA BOOK FOR WATER AT BULK TEMPERATURE OF 80 degree C\n", + "d = 974.;\t\t \t#Density in kg/m**3\n", + "v1 = 0.000000364;\t\t#Kinematic viscosity in m**2/s\n", + "k1 = 0.6687;\t\t\t#Thermal conductivity in W/m.K\n", + "Pr = 2.2;\t\t\t #Prantl Number\n", + "\n", + "# Calculations\n", + "Re = (v*Di)/v1;\t\t\t#Reynold's number\n", + "Nu = (0.023*Re**0.8*Pr**0.4);\t\t\t#Nusselts number\n", + "hi = Nu*(k1/Di);\t\t\t#Heat transfer coefficient in W/m**2.K\n", + "ri = (Di/2);\t\t\t#Inner radius of steel pipe in m\n", + "ro = (Do/2);\t\t\t#Outer radius of steel pipe in m\n", + "U = (1./((1./ho)+((ro/k)*math.log(ro/ri))+(ro/(ri*hi))));\t\t\t#Overall heat transfer coefficient in W/m**2.K\n", + "\n", + "# Results\n", + "print 'Overall heat transfer coefficient is %3.1f W/m**2.K'%(U)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Overall heat transfer coefficient is 2591.8 W/m**2.K\n" + ] + } + ], + "prompt_number": 1 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 12.2 Page No : 504" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math\n", + "# Variables\n", + "Do = 0.0254;\t\t\t#Outer Diameter of heat exchanger tube in m\n", + "Di = 0.02286;\t\t\t#Inner Diameter of heat exchanger tube in m\n", + "k = 102;\t\t\t#Thermal conductivity of the tube in W/m.K\n", + "hi = 5500;\t\t\t#Heat transfer coefficients at the inner side of tube in W/m**2.K\n", + "ho = 3800;\t\t\t#Heat transfer coefficients at the outer side of tube in W/m**2.K\n", + "Rfi = 0.0002;\t\t\t#Fouling factor in m**2.W.K\n", + "Rfo = 0.0002;\t\t\t#Fouling factor in m**2.W.K\n", + "\n", + "# Calculations\n", + "ro = (Do/2);\t\t\t#Outer radius of heat exchanger tube in m\n", + "ri = (Di/2);\t\t\t#Inner radius of heat exchanger tube in m\n", + "U = (1./((1./ho)+Rfo+((ro/k)*math.log(ro/ri))+((ro*Rfi)/ri)+(ro/(ri*hi))));\t\t\t#Overall heat transfer coefficient in W/m**2.K\n", + "\n", + "# Results\n", + "print 'Overall heat transfer coefficient is %i W/m**2.K'%(U)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Overall heat transfer coefficient is 1110 W/m**2.K\n" + ] + } + ], + "prompt_number": 3 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 12.3 Page No : 509" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math\n", + "# Variables\n", + "mh = 10000.;\t\t\t#Mass flow rate of oil in kg/h\n", + "ch = 2095.;\t\t\t#Specific heat of oil J/kg.K\n", + "Thi = 80.;\t\t\t#Inlet temperature of oil in degree C\n", + "Tho = 50.;\t\t\t#Outlet temperature of oil in degree C\n", + "mc = 8000.;\t\t\t#Mass flow rate of water in kg/h\n", + "Tci = 25.;\t\t\t#Inlet temperature of water in degree C\n", + "U = 300.;\t\t\t#Overall heat ransfer coefficient in W/m**2.K\n", + "cc = 4180.;\t\t\t#Specific heat of water in J/kg.K\n", + "\n", + "# Calculations\n", + "Q = (mh*ch*(Thi-Tho));\t\t\t#Heat transfer rate in W\n", + "Tco = ((Q/(mc*cc))+Tci);\t\t\t#Outlet temperature of water in degree C\n", + "T = (Thi-Tco);\t\t\t#Temperature difference between oil inlet temperature and water outlet temperature in degree C\n", + "t = (Tho-Tci);\t\t\t#Temperature difference between oil outlet temperature and water inlet temperature in degree C\n", + "A = (((Q/U)*math.log(t/T))/(3600*(t-T)));\t\t\t#Area of heat exchanger in m**2\n", + "\n", + "# Results\n", + "print 'Area of heat exchanger is %3.2f m**2'%(A)\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Area of heat exchanger is 19.23 m**2\n" + ] + } + ], + "prompt_number": 4 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 12.4 Page No : 510" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math\n", + "# Variables\n", + "Ch = 2500.;\t\t\t#Capacity rate of hot oil in W/K\n", + "Thi = 360.;\t\t\t#Temperature of hot fluid at the entrance of heat exchanger in degree C\n", + "Tho = 300.;\t\t\t#Temperature of hot fluid at the exit of heat exchanger in degree C\n", + "Tci = 30.;\t\t\t#Temperature of cold fluid at the entrance of heat exchanger in degree C\n", + "Tco = 200.;\t\t\t#Temperature of hot fluid at the exit of heat exchanger in degree C\n", + "U = 800.;\t\t\t#Overall heat transfer coefficient in W/m**2.K\n", + "\n", + "# Calculations\n", + "Q = (Ch*(Thi-Tho));\t\t\t#Heat transfer from the oil in W\n", + "#Parallel flow\n", + "T1 = Thi-Tci;\t\t\t#Temperature difference between hot fluid inlet temperature and cold fluid inlet temperature in degree C\n", + "T2 = Tho-Tco;\t\t\t#Temperature difference between hot fluid outlet temperature and cold fluid outlet temperature in degree C\n", + "Tlm1 = ((T1-T2)/math.log(T1/T2));\t\t\t#LMTD for parallel flow arrangement in degree C\n", + "A1 = (Q/(U*Tlm1));\t\t\t#Area of heat exchanger in m**2\n", + "#Counter flow\n", + "t1 = Thi-Tco;\t\t\t#Temperature difference between hot fluid inlet temperature and cold fluid outlet temperature in degree C\n", + "t2 = Tho-Tci;\t\t\t#Temperature difference between hot fluid outlet temperature and cold fluid inlet temperature in degree C\n", + "Tlm2 = ((t1-t2)/math.log(t1/t2));\t\t\t#LMTD for counter flow arrangement in degree C\n", + "A2 = (Q/(U*Tlm2));\t\t\t#Area of heat exchanger in m**2\n", + "\n", + "# Results\n", + "print 'Area of heat exchanger in parallel flow arrangement is %3.3f m**2 \\n \\\n", + "Area of heat exchanger in counter flow arrangement is %3.3f m**2'%(A1,A2)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Area of heat exchanger in parallel flow arrangement is 0.973 m**2 \n", + " Area of heat exchanger in counter flow arrangement is 0.892 m**2\n" + ] + } + ], + "prompt_number": 6 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 12.5 Page No : 511" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math\n", + "# Variables\n", + "ch = 2130.;\t\t\t#Specific heat of oil in J/kg.K\n", + "T1 = 160.;\t\t\t#Temperature of hot fluid (oil) at the entrance of heat exchanger in degree C\n", + "T2 = 60.;\t\t\t#Temperature of hot fluid (oil) at the exit of heat exchanger in degree C\n", + "t1 = 25.;\t\t\t#Temperature of cold fluid (water) at the entrance of heat exchanger in degree C\n", + "d = 0.5;\t\t\t#Inner diameter of the tube in m\n", + "mc = 2.;\t\t\t#Mass flow rate of cooling water in kg/s\n", + "D = 0.7;\t\t\t#outer annulus outer diameter in m\n", + "mh = 2.;\t\t\t#Mass flow rate of hot oil in kg/s\n", + "U = 250.;\t\t\t#Overall heat transfer coefficient in W/m**2.K\n", + "cc = 4186.;\t\t\t#Specific heat of water in J/kg.K\n", + "\n", + "# Calculations\n", + "Q = (mh*ch*(T1-T2));\t\t\t# Required heat transfer rate in W\n", + "t2 = ((Q/(mc*cc))+t1);\t\t\t#Outer water temperature in degree C\n", + "T = T1-t2; \t \t\t #Change in temperature between inlet tmperature of hot fluid and outlet temperature of cold fluid in degree C\n", + "t = T2-t1;\t \t \t#Change in temperature between outlet tmperature of hot fluid and inlet temperature of cold fluid in degree C\n", + "Tlm = ((T-t)/(math.log(T/t)));\t#Value of LMTD in degree C\n", + "L = (Q/(U*3.14*d*Tlm));\t\t\t#Length of the heat exchanger in m\n", + "\n", + "# Results\n", + "print 'Length of the heat exchanger is %3.2f m'%(L)\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Length of the heat exchanger is 19.38 m\n" + ] + } + ], + "prompt_number": 7 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 12.6 Page No : 512" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "T = 120.;\t\t\t#Saturated steam temperature in degree C\n", + "U = 1800.;\t\t\t#Heat transfer coefficient in W/m**2.K\n", + "m = 1000.;\t\t\t#mass flow rate of water in kg/h\n", + "t1 = 20.;\t\t\t#Inlet temperature of water in degree C\n", + "t2 = 90.;\t\t\t#Outlet tmperature of water in degree C\n", + "hfg = 2200.;\t\t#Enthalpy of steam in kJ/kg\n", + "c = 4186.;\t\t\t#Specific het of water in J/kg.K\n", + "\n", + "# Calculations\n", + "Tlm = (((T-t1)-(T-t2))/(math.log((T-t1)/(T-t2))));\t\t\t#LMTD in a condenser in degree C\n", + "Q = ((m/3600)*c*(t2-t1));\t \t\t#Rate of heat transfer in W\n", + "A = (Q/(U*Tlm));\t\t \t#Surface area of heat exchanger in m**2 \n", + "ms = ((Q*3600)/(hfg*1000));\t\t \t#Rate of condensation of steam in kg/h\n", + "\n", + "# Results\n", + "print 'Surface area of heat exchanger is %3.2f m**2 \\n \\\n", + "Rate of condensation of steam is %3.1f kg/h'%(A,ms)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Surface area of heat exchanger is 0.78 m**2 \n", + " Rate of condensation of steam is 133.2 kg/h\n" + ] + } + ], + "prompt_number": 8 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 12.7 Page No : 516" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math\n", + "# Variables\n", + "T = 100.;\t\t\t#Temperature of saturated steam in degree C\n", + "t1 = 30.;\t\t\t#Inlet temperature of water in degree C\n", + "t2 = 70.;\t\t\t#Exit temperature of water in degree C\n", + "\n", + "# Calculations\n", + "#COUNTER FLOW\n", + "Tc = (T-t2);\t\t\t#Temperature difference between saturated steam and exit water temperature in degree C\n", + "tc = (T-t1);\t\t\t#Temperature difference between saturated steam and inlet water temperature in degree C\n", + "Tlmc = ((Tc-tc)/math.log(Tc/tc));\t\t\t#LMTD for counter flow in degree C\n", + "\n", + "#PARALLEL FLOW\n", + "Tp = (T-t1);\t\t\t#Temperature difference between saturated steam and inlet water temperature in degree C\n", + "tp = (T-t2);\t\t\t#Temperature difference between saturated steam and exit water temperature in degree C\n", + "Tlmp = ((Tp-tp)/math.log(Tp/tp));\t\t\t#LMTD for counter flow in degree C\n", + "#CROSS FLOW\n", + "R = ((T-T)/(t2-t1));\t\t\t#R value for Correction factor F\n", + "P = ((t2-t1)/(T-t1));\t\t\t#P value for Correction Factor F\n", + "F = 1;\t\t\t#Referring to Fig.12.12 in page no 515\n", + "Tlmx = (F*Tlmc);\t\t\t#LMTD for cross flow in degree C\n", + "\n", + "# Results\n", + "print 'The effective math.log mean temperature difference for: \\\n", + "\\ni)COUNTER FLOW is %3.1f degree C \\\n", + "\\nii)PARALLEL FLOW is %3.1f degree C \\niii)CROSS FLOW is %3.1f degree C'%(Tlmc,Tlmp,Tlmx)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "The effective math.log mean temperature difference for: \n", + "i)COUNTER FLOW is 47.2 degree C \n", + "ii)PARALLEL FLOW is 47.2 degree C \n", + "iii)CROSS FLOW is 47.2 degree C\n" + ] + } + ], + "prompt_number": 11 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 12.8 Page No : 516" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "Ti = 18;\t\t\t#Inlet temperature of Shell fluid in degree C\n", + "To = 6.5;\t\t\t#Outlet temperature of Shell fluid in degree C\n", + "ti = -1.1;\t\t\t#Inlet temperature of Tube fluid in degree C\n", + "to = 2.9;\t\t\t#Outlet temperature of Tube fluid in degree C\n", + "U = 850;\t\t\t#Overall heat transfer coefficient in W/m**2.K\n", + "Q = 6000;\t\t\t#Design heat load in W\n", + "\n", + "# Calculations\n", + "T = (Ti-to);\t\t\t#Temperature difference between shell side inlet fluid and tube side outlet fluid in degree C\n", + "t = (To-ti);\t\t\t#Temperature difference between shell side outlet fluid and tube side inlet fluid in degree C\n", + "Tlm = ((T-t)/math.log(T/t));\t\t\t#LMTD for a counterflow arrangement in degree C\n", + "P = ((to-ti)/(Ti-ti));\t\t\t#P value to calculate correction factor\n", + "R = ((Ti-To)/(to-ti));\t\t\t#R value to calculate correction factor\n", + "F = 0.97\t\t\t#Taking correction factor from fig. 12.9 on page no.514\n", + "A = (Q/(U*F*Tlm));\t\t\t#Area of shell aand tube heat exchanger in m**2\n", + "\n", + "# Results\n", + "print 'Area of shell-and-tube heat exchanger is %3.2f m**2'%(A)\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Area of shell-and-tube heat exchanger is 0.67 m**2\n" + ] + } + ], + "prompt_number": 12 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 12.9 Page No : 517" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "Q = 6000;\t\t\t#Taking design heat load value in W from Example no. 12.8 on page no.516\n", + "U = 850;\t\t\t#Taking overall heat transfer coefficient value in W/m**2.K from Example no. 12.8 on page no.516\n", + "Tlm = 10.92\t\t\t#Taking LMTD for a counterflow arrangement in degree C from Example no. 12.8 on page no.517\n", + "R = 2.875;\t\t\t#Taking R value from Example no. 12.8 on page no.517\n", + "P = 0.209;\t\t\t#Taking P value from Example no. 12.8 on page no.517\n", + "F = 0.985;\t\t\t#Taking correction factor from Fig. 12.10 on page no.514\n", + "\n", + "# Calculations\n", + "A = (Q/(U*F*Tlm));\t\t\t#Area of shell-and-tube heat exchanger in m**2\n", + "\n", + "# Results\n", + "print 'Area of shell aand tube heat exchanger is %3.3f m**2'%(A)\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Area of shell aand tube heat exchanger is 0.656 m**2\n" + ] + } + ], + "prompt_number": 13 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 12.10 Page No : 517" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "Ti = 360.;\t\t\t#Inlet temperature of hot fluid in degree C taken from Example no. 12.4 on page no. 510\n", + "To = 300.;\t\t\t#Outlet temperature of hot fluid in degree C taken from Example no. 12.4 on page no. 510\n", + "ti = 30.;\t\t\t#Inlet temperature of cold fluid in degree C taken from Example no. 12.4 on page no. 510\n", + "to = 200.;\t\t\t#Outlet temperature of cold fluid in degree C taken from Example no. 12.4 on page no. 510\n", + "U = 800.;\t\t\t#Overall heat transfer coefficient in W/m**2.K taken from Example no. 12.4 on page no. 510\n", + "Q = 150000.;\t\t\t#Calculated heat transfer rate in W from Example no. 12.4 on page no. 510 \n", + "Tlm = 210.22\t\t\t#Calculated LMTD for counterflow arrangement in degree C taken from Example no. 12.4 on page no. 511\n", + "\n", + "# Calculations\n", + "P = ((to-ti)/(Ti-ti));\t\t\t#P value for calculation of correction factor\n", + "R = ((Ti-To)/(to-ti));\t\t\t#R value for calculation of correction factor\n", + "F = 0.98;\t\t\t#Correction Factor value taken from Fig.12.11 on page no.515\n", + "A = (Q/(U*F*Tlm));\t\t\t#Required surface area in a cross flow heat exchanger in m**2\n", + "\n", + "# Results\n", + "print 'The required surface area in a cross flow heat exchanger is %3.2f m**2'%(A)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "The required surface area in a cross flow heat exchanger is 0.91 m**2\n" + ] + } + ], + "prompt_number": 14 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 12.11 Page No : 518" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math\n", + "# Variables\n", + "mc = 4.;\t\t\t#Mass flow rate of cold water in kg/s\n", + "Tci = 38.;\t\t\t#Inlet Temperature of cold water in degree C\n", + "Tco = 55.;\t\t\t#Outlet Temperature of cold water in degree C\n", + "D = 0.02;\t\t\t#Diameter of the tube in m\n", + "v = 0.35;\t\t\t#Velocity of water in m/s\n", + "Thi = 95.;\t\t\t#Inlet Temperature of hot water in degree C\n", + "mh = 2.;\t\t\t#Mass flow rate of hot water in kg/s\n", + "L = 2.;\t\t\t #Length of the tube in m\n", + "U = 1500.;\t\t\t#Overall heat transfer coefficient in W/m**2.K\n", + "c = 4186.;\t\t\t#Specific heat of water in J/kg.K\n", + "d = 1000.;\t\t\t#Density of water in kg/m**3\n", + "\n", + "# Calculations\n", + "Q = (mc*c*(Tco-Tci));\t\t\t#Heat transfer rate for cold fluid in W\n", + "Tho = (Thi-(Q/(mh*c)));\t\t\t#Outlet temperature of hot fluid in degree C\n", + "T = Thi-Tco;\t\t\t#Difference of temperature between hot water inlet and cold water outlet in degree C\n", + "t = Tho-Tci;\t\t\t#Difference of temperature between hot water outlet and cold water inlet in degree C\n", + "Tlm = ((T-t)/math.log(T/t));\t\t\t#LMTD for counterflow heat exchanger\n", + "A = (Q/(U*Tlm));\t\t\t#Area of heat exchanger in m**2\n", + "A1 = (mc/(d*v));\t\t\t#Total flow area in m**2\n", + "n = ((A1*4)/(3.14*D**2));\t\t\t#Number of tubes\n", + "L = (A/(36*3.14*D));\t\t\t#Length of each tube taking n = 36 in m\n", + "N = 2;\t\t\t#Since this length is greater than the permitted length of 2m, we must use more than one tube pass. Let us try 2 tube passes\n", + "P = ((Tco-Tci)/(Thi-Tci));\t\t\t#P value for calculation of correction factor\n", + "R = ((Thi-Tho)/(Tco-Tci));\t\t\t#R value for calculation of correction factor\n", + "F = 0.9;\t\t\t#Corrction Factor from Fig.12.9 on page no. 514 \n", + "A2 = (Q/(U*F*Tlm));\t\t\t#Total area required for one shall pass,2 tube pass exchanger in m**2\n", + "L1 = (A2/(2*36*3.14*D));\t\t\t#Length of tube per pass taking n = 36 in m\n", + "\n", + "# Results\n", + "print 'Number of tubes per pass is %.f \\n \\\n", + "Number of passes is %i \\n \\\n", + "Length of tube per pass is %3.3f m'%(n,N,L1)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Number of tubes per pass is 36 \n", + " Number of passes is 2 \n", + " Length of tube per pass is 1.518 m\n" + ] + } + ], + "prompt_number": 4 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 12.12 Page No : 524" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math\n", + "# Variables\n", + "mh = 250.;\t\t\t#Mass flow rate of hot liquid in kg/h\n", + "ch = 3350.;\t\t\t#Specific heat of hot liquid in J/kg.K\n", + "Thi = 120.;\t\t\t#Inlet temperature of hot liquid in degree C\n", + "mc = 1000.;\t\t\t#Mass flow rate of cold liquid in kg/h\n", + "Tci = 10.;\t\t\t#Inlet temperature of cold liquid in degree C\n", + "U = 1160.;\t\t\t#Overall heat transfer coefficient in W/m**2.K\n", + "A = 0.25;\t\t\t#Surface area of heat exchanger in m**2\n", + "cc = 4186.;\t\t\t#Specific heat of cold liquid in J/kg.K\n", + "\n", + "# Calculations\n", + "Cc = ((mc*cc)/3600);\t\t\t#Heat capacity rate for cold liquid in W/K\n", + "Ch = ((mh*ch)/3600);\t\t\t#Heat capacity rate for hot liquid in W/K\n", + "Cmin = min(Cc,Ch);\t\t\t#Minimum heat capacity rate in W/K\n", + "Cmax = max(Cc,Ch);\t\t\t#Maximum heat capacity rate in W/K\n", + "r = (Cmin/Cmax);\t\t\t#Ratio of min amd max heat capacity rates\n", + "NTU = ((U*A)/Cmin);\t\t\t#Number of transfer units\n", + "e = ((1-math.exp(-NTU*(1+r)))/(1+r));\t\t\t#Effectiveness for a parallel flow heat exchanger\n", + "Qmax = (Cmin*(Thi-Tci));\t\t\t#Maximum possible heat transfer rate in W\n", + "Q = (e*Qmax);\t\t\t#Actual rate of heat transfer in W\n", + "Tco = ((Q/Cc)+Tci);\t\t\t#Outlet temperature of cold liquid in degree C\n", + "Tho = (Thi-(Q/Ch));\t\t\t#Outlet temperature of hot liquid in degree C\n", + "\n", + "\n", + "# Results\n", + "print 'Effectiveness for a parallel flow heat exchanger is %3.3f \\n \\\n", + "Outlet temperature of water is %3.2f degree C \\n \\\n", + "Outlet temperature of cooled liquid is %3.2f degree C'%(e,Tco,Tho)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Effectiveness for a parallel flow heat exchanger is 0.647 \n", + " Outlet temperature of water is 24.23 degree C \n", + " Outlet temperature of cooled liquid is 48.87 degree C\n" + ] + } + ], + "prompt_number": 18 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 12.13 Page No : 527" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "Tci = 15.;\t\t\t#Inlet temperature of water in degree C\n", + "mc = 1300.;\t\t\t#Mass flow rate of water in kg/h\n", + "ch = 2000.;\t\t\t#Specific heat of oil in J/kg.K\n", + "mh = 550.;\t\t\t#Mass flow rate of oil in kg/h\n", + "Thi = 94.;\t\t\t#Inlet temperature of oil in degree C\n", + "A = 1.;\t\t\t #Area of heat exchanger in m**2\n", + "U = 1075.;\t\t\t#Overall heat transfer coefficient in W/m**2.K\n", + "cc = 4186.;\t\t\t#Specific heat of water in J/kg.K\n", + "\n", + "# Calculations\n", + "Cc = ((mc*cc)/3600);\t\t\t#Heat capacity of water in W/K\n", + "Ch = ((mh*ch)/3600);\t\t\t#Heat capacity of oil in W/K\n", + "Cmin = min(Cc,Ch);\t\t\t#Minimum heat capacity in W/K\n", + "Cmax = max(Cc,Ch);\t\t\t#Maximum heat capacity in W/K\n", + "r = (Cmin/Cmax);\t\t\t#Ratio of min and max heat capacity\n", + "NTU = ((U*A)/Cmin);\t\t\t#Number of transfer Units\n", + "e = 0.94\t\t\t#Effectiveness of heat exchanger from Fig. 12.15 on page no.524\n", + "Qmax = (Cmin*(Thi-Tci));\t\t\t#Maximum possible heat transfer rate in W\n", + "Q = (e*Qmax);\t\t\t#Actual heat transfer rate in W\n", + "Tco = ((Q/Cc)+Tci);\t\t\t#Outlet Temperature of water in degree C\n", + "Tho = (Thi-(Q/Ch));\t\t\t#Outlet Temperature of oil in degree C\n", + "\n", + "# Results\n", + "print 'The total heat transfer is %3.1f W \\n \\\n", + "Outlet Temperature of water is %i degree C \\n \\\n", + "Outlet Temperature of oil is %3.2f degree C'%(Q,Tco,Tho)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "The total heat transfer is 22690.6 W \n", + " Outlet Temperature of water is 30 degree C \n", + " Outlet Temperature of oil is 19.74 degree C\n" + ] + } + ], + "prompt_number": 5 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 12.14 Page No : 528" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "N = 3000.;\t\t\t#Number of brass tubes\n", + "D = 0.02;\t\t\t#Diameter of brass tube in m\n", + "Tci = 20.;\t\t\t#Inlet temperature of cooling water in degree C\n", + "mc = 3000.;\t\t\t#Mass flow rate of cooling water in kg/s\n", + "ho = 15500.;\t\t\t#Heat transfer coefficient for condensation in W/m**2.K\n", + "Q = (2.3*10**8);\t\t\t#Heat load of the condenser in W\n", + "Thi = 50.;\t\t\t#Temperature at which steam condenses in degree C\n", + "hfg = 2380.\t\t\t#Enthalpy of liquid vapour mixture in kJ/kg\n", + "m = 1.;\t\t\t#Flow rate of each tube in kg/s\n", + "Cc = 4180.;\t\t\t#Specific heat of water in J/kg.K\n", + "#Properties of water at 300K from data book\n", + "Cc = 4186.;\t\t\t#Specific heat in J/kg.K\n", + "mu = (855.*10**-6);\t\t\t#Dynamic vismath.cosity in Ns/m**2\n", + "k = 0.613;\t\t\t#Thermal Conductivity in W/mK\n", + "Pr = 5.83\t\t\t#Prantl number\n", + "\n", + "# Calculations\n", + "Tco = ((Q/(mc*Cc))+Tci);\t\t\t#Outlet temperature of cooling water in degree C\n", + "Re = ((4*m)/(3.1415*D*mu));\t\t\t#Reynold's number\n", + "Nu = (0.023*Re**(4./5)*Pr**(2./5));\t\t\t#Nusselts number\n", + "hi = (Nu*(k/D));\t\t\t#Heat transfer coefficient in W/m**2.K\n", + "U = (1./((1./ho)+(1./hi)));\t\t\t#Overall heat transfer coefficient in W/m**2.K\n", + "Cmin = (mc*Cc);\t\t\t#Minimum heat capacity in W/K\n", + "Qmax = (Cmin*(Thi-Tci));\t\t\t#Maximum heat transfer rate in W\n", + "e = (Q/Qmax);\t\t\t#Effectiveness of heat transfer\n", + "NTU = 0.8;\t\t\t#Number of transfer units from Fig. 12.16 on page no.525 \n", + "A = ((NTU*Cmin)/U);\t\t\t#Area of heat exchanger in m**2\n", + "L = (A/(2*N*3.1415*D));\t\t\t#Length of tube per pass in m\n", + "ms = (Q/(hfg*1000));\t\t\t#Amount of steam condensed in kg/s\n", + "\n", + "# Results\n", + "print 'The outlet temperature of the cooling water is %3.2f degree C \\n \\\n", + "The overall heat transfer coefficient is %3.1f W/m**2.K \\n \\\n", + "Tube length per pass using NTU method is %3.2f m \\n \\\n", + "The rate of condensation of steam is %3.0f kg/s'%(Tco,U,L,ms)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "The outlet temperature of the cooling water is 38.32 degree C \n", + " The overall heat transfer coefficient is 6525.8 W/m**2.K \n", + " Tube length per pass using NTU method is 4.08 m \n", + " The rate of condensation of steam is 97 kg/s\n" + ] + } + ], + "prompt_number": 20 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 12.15 Page No : 530" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "Tci = 5.;\t\t\t#Inlet temperature of water in degree C\n", + "mc = 4600.;\t\t\t#Mass flow rate of water in kg/h\n", + "mh = 4000.;\t\t\t#Mass flow rate of air in kg/h\n", + "Thi = 40.;\t\t\t#Inlet temperature of air in degree C\n", + "U = 150.;\t\t\t#Overall heat transfer coefficient in W/m**2.K\n", + "A = 25.;\t\t\t#Area of heat exchanger in m**2\n", + "Cc = 4180.;\t\t\t#Specific heat of water in J/kg.K\n", + "Ch = 1010.;\t\t\t#Specific heat of air in J/kg.K\n", + "\n", + "# Calculations\n", + "C1 = ((mh*Ch)/3600);\t\t\t#Heat capacity of air in W/K\n", + "C2 = ((mc*Cc)/3600);\t\t\t#Heat capacity of water in W/K\n", + "Cmin = min(C1,C2);\t\t\t#Minimum value of heat capacity in W/K\n", + "Cmax = max(C1,C2);\t\t\t#Maximum value of heat capacity in W/K\n", + "r = (Cmin/Cmax);\t\t\t#Ratio of min and max heat capacity in W/K\n", + "NTU = ((U*A)/Cmin);\t\t\t#Number of heat transfer units\n", + "e = 0.92;\t\t\t#Effectiveness of heat exchanger from Fig. 12.18 on page no.526\n", + "Q = (e*Cmin*(Thi-Tci));\t\t\t#Heat transfer rate in W\n", + "Tco = ((Q/C2)+Tci);\t\t\t#Outlet temperature of water in degree C\n", + "Tho = (Thi-(Q/C1));\t\t\t#Outlet temperature of air in degree C\n", + "\n", + "# Results\n", + "print 'The exit temperature of water is %3.1f degree C \\n \\\n", + "The exit temperature of air is %3.1f degree C'%(Tco,Tho)\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "The exit temperature of water is 11.8 degree C \n", + " The exit temperature of air is 7.8 degree C\n" + ] + } + ], + "prompt_number": 21 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 12.16 Page No : 532" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "A = 15.82;\t\t\t#Total outside area of heat exchanger in m**2\n", + "Thi = 110;\t\t\t#Inlet temperature of oil in degree C\n", + "Ch = 1900;\t\t\t#Specific heat of oil in J/kg.K\n", + "mh = 170.9;\t\t\t#Mass flow rate of oil in kg/min\n", + "mc = 68;\t\t\t#Mass flow rate of water in kg/min\n", + "Tci = 35;\t\t\t#Inlet temperature of water in degree C\n", + "U = 320;\t\t\t#Overall heat transfer coefficient in W/m**2.K\n", + "Cc = 4186;\t\t\t#Specific heat of water in J/kg.K\n", + "\n", + "# Calculations\n", + "C1 = ((mh*Ch)/60);\t\t\t#Heat capacity of oil in W/K\n", + "C2 = ((mc*Cc)/60);\t\t\t#Heat capacity of water in W/K\n", + "D = (U*A*((1./C1)-(1./C2)));\t\t\t#Constant\n", + "r = (C1/C2);\t\t\t#Ratio of heat capacity of oil and water\n", + "Tho = Thi-(((Thi-Tci)*(1-math.exp(D)))/(r-math.exp(D)));\t\t\t#Outlet temperature of oil in degree C\n", + "Tco = Tci+(r*(Thi-Tho));\t\t\t#Outlet temperature of water in degree C\n", + "\n", + "# Results\n", + "print 'The exit temperature of oil is %3.2f degree C \\n \\\n", + " The exit temperature of water is %3.1f degree C'%(Tho,Tco)\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "The exit temperature of oil is 74.97 degree C \n", + " The exit temperature of water is 75.0 degree C\n" + ] + } + ], + "prompt_number": 23 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 12.17 Page No : 533" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "Tci = 20.;\t\t\t#Inlet temperature of water in degree C\n", + "Tco = 50.;\t\t\t#Outlet temperature of water in degree C\n", + "Th = 120.;\t\t\t#Temperature at which steam condenses in degree C\n", + "newTci = 15.;\t\t\t#New Inlet temperature of water in degree C\n", + "\n", + "# Calculations\n", + "newTco = (((Tco-Tci)*(Th-newTci))/(Th-Tci))+newTci;\t\t\t#New outlet temperature of water in degree C\n", + "\n", + "# Results\n", + "print 'New outlet temperature of water is %3.1f degree C'%(newTco)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "New outlet temperature of water is 46.5 degree C\n" + ] + } + ], + "prompt_number": 24 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 12.18 Page No : 534" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "T = 100;\t\t\t#Total length of tubes in m\n", + "\n", + "\n", + "# Calculations\n", + "D = ((3.14*4000)/(3.14*30000))**0.5;\t\t\t#Diameter of the exchanger in m\n", + "L = (2./(3.1415*D**2));\t\t\t#Length of the exchanger in m\n", + "Cost = (10000+(15000*D**3*L)+(2000*D*L));\t\t\t#Optimal math.cost in Rs\n", + "\n", + "# Results\n", + "print 'The diameter of the exchanger is %3.3f m \\n \\\n", + "The Length of the exchanger is %3.2f m \\n \\\n", + "Optimal cost is %3.0f Rs'%(D,L,Cost)\n", + "\n", + "# note : rounding error." + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "The diameter of the exchanger is 0.365 m \n", + " The Length of the exchanger is 4.77 m \n", + " Optimal cost is 16974 Rs\n" + ] + } + ], + "prompt_number": 8 + } + ], + "metadata": {} + } + ] +}
\ No newline at end of file diff --git a/Fundamentals_Of_Engineering_Heat_And_Mass_Transfer/ch13.ipynb b/Fundamentals_Of_Engineering_Heat_And_Mass_Transfer/ch13.ipynb new file mode 100755 index 00000000..bbf39026 --- /dev/null +++ b/Fundamentals_Of_Engineering_Heat_And_Mass_Transfer/ch13.ipynb @@ -0,0 +1,444 @@ +{ + "metadata": { + "name": "", + "signature": "sha256:154cdfdbffe4cd226ec00ca571625579dcd760fa5b25d6fc7f505d761a2beb76" + }, + "nbformat": 3, + "nbformat_minor": 0, + "worksheets": [ + { + "cells": [ + { + "cell_type": "heading", + "level": 1, + "metadata": {}, + "source": [ + "Chapter 13 : Diffusion Mass Transfer" + ] + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 13.1 Page No : 544" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "ro2 = 0.21;\t\t\t#Ratio of O2 in the mixture \n", + "rn2 = 0.79;\t\t\t#Ratio of N2 in the mixture \n", + "T = (25+273);\t\t\t#Temperature of container in degree C\n", + "p = 1;\t\t\t#Total pressure in atm\n", + "\n", + "# Calculations\n", + "Co2 = (ro2*10**5)/(8314*T);\t\t\t#Molar concentration of O2 in K.mol/m**3\n", + "Cn2 = (rn2*10**5)/(8314*T);\t\t\t#Molar concentration of N2 in K.mol/m**3\n", + "po2 = (32*Co2);\t\t\t#Mass density in kg/m**3\n", + "pn2 = (28*Cn2);\t\t\t#Mass density in kg/m**3\n", + "p = (po2+pn2);\t\t\t#Overall mass density in kg/m**3\n", + "mo2 = (po2/p);\t\t\t#Mass fraction of O2\n", + "mn2 = (pn2/p);\t\t\t#Mass fraction of N2\n", + "M = (ro2*32)+(rn2*28);\t\t\t#Average molecular weight \n", + "\n", + "# Results\n", + "print 'Molar concentration of O2 is %3.4f K.mol/m**3 \\n \\\n", + "Molar concentration of N2 is %3.3f K.mol/m**3 \\n \\\n", + "Mass density of O2 is %3.3f kg/m**3 \\n \\\n", + "Mass density of N2 is %3.3f kg/m**3 \\n \\\n", + "Mole fraction of O2 is %3.2f \\n \\\n", + "Mole fraction of N2 is %3.2f \\n \\\n", + "Mass fraction of O2 is %3.3f \\n \\\n", + "Mass fraction of N2 is %3.3f \\n \\\n", + "Average molecular weight is %3.2f'%(Co2,Cn2,po2,pn2,ro2,rn2,mo2,mn2,M)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Molar concentration of O2 is 0.0085 K.mol/m**3 \n", + " Molar concentration of N2 is 0.032 K.mol/m**3 \n", + " Mass density of O2 is 0.271 kg/m**3 \n", + " Mass density of N2 is 0.893 kg/m**3 \n", + " Mole fraction of O2 is 0.21 \n", + " Mole fraction of N2 is 0.79 \n", + " Mass fraction of O2 is 0.233 \n", + " Mass fraction of N2 is 0.767 \n", + " Average molecular weight is 28.84\n" + ] + } + ], + "prompt_number": 1 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 13.2 Page No : 545" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "yh2 = 0.4;\t\t\t#Mole fraction og H2\n", + "yo2 = 0.6;\t\t\t#Mole fraction of O2\n", + "vh2 = 1;\t\t\t#velocity of H2 in m/s\n", + "vo2 = 0;\t\t\t#velocity of O2 in m/s\n", + "\n", + "# Calculations\n", + "V = (yh2*vh2)+(yo2*vo2);\t\t#Molar average velocity in m/s\n", + "M = (yh2*2)+(yo2*32);\t\t\t#Molecular weight of the mixture\n", + "mh2 = (yh2*2)/M;\t \t\t#Mass fraction of H2 \n", + "mo2 = (yo2*32)/M;\t\t \t#Mass fraction of O2\n", + "v = (mh2*vh2)+(mo2*vo2);\t\t#Mass average velocity in m/s\n", + "x1 = (mh2*vh2);\t\t\t #Mass flux \n", + "x2 = (mo2*vo2);\t\t\t #Mass flux\n", + "y1 = (v*vh2);\t\t \t #Molar flux\n", + "y2 = (yo2*vo2);\t \t\t #Molar flux\n", + "jh2 = (mh2*(vh2-v));\t\t\t#Mass diffusion flux\n", + "jo2 = (mo2*(vo2-v));\t\t\t#Mass diffusion flux\n", + "Jh2 = (yh2*(vh2-V));\t\t\t#Molar diffusion flux\n", + "Jo2 = (yo2*(vo2-V));\t\t\t#Molar diffusion flux\n", + "\n", + "# Results\n", + "print 'Molar average velocity is %3.1f m/s \\n \\\n", + "Mass average velocity is %3.2f m/s \\n \\\n", + "Mass flux of H2 when it is stationary is %3.2fp kg/m2.s3 \\n \\\n", + "Mass flux of O2 when it is stationary is %3.0f kg/m**2.s \\n \\\n", + "Molar flux of H2 when it is stationary is %3.2fC k.mol/m**2.s \\n \\\n", + "Molar flux of O2 when it is stationary is %3.0f k.mol/m**2.s \\n \\\n", + "Mass diffusion flux of H2 across a surface moving with mass average velocity is %3.4fp kg/m**2.s \\n \\\n", + "Mass diffusion flux of O2 across a surface moving with mass average velocity is %3.4fp kg/m**2.s \\n \\\n", + "Molar diffusion flux across a surface moving with molar average velociy for H2 is %3.2fC k.mol/m**2.s \\n \\\n", + "Molar diffusion flux across a surface moving with molar average velociy for O2\\\n", + " is %3.2fC k.mol/m**2.s'%(V,v,x1,x2,y1,y2,jh2,jo2,Jh2,Jo2)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Molar average velocity is 0.4 m/s \n", + " Mass average velocity is 0.04 m/s \n", + " Mass flux of H2 when it is stationary is 0.04p kg/m2.s3 \n", + " Mass flux of O2 when it is stationary is 0 kg/m**2.s \n", + " Molar flux of H2 when it is stationary is 0.04C k.mol/m**2.s \n", + " Molar flux of O2 when it is stationary is 0 k.mol/m**2.s \n", + " Mass diffusion flux of H2 across a surface moving with mass average velocity is 0.0384p kg/m**2.s \n", + " Mass diffusion flux of O2 across a surface moving with mass average velocity is -0.0384p kg/m**2.s \n", + " Molar diffusion flux across a surface moving with molar average velociy for H2 is 0.24C k.mol/m**2.s \n", + " Molar diffusion flux across a surface moving with molar average velociy for O2 is -0.24C k.mol/m**2.s\n" + ] + } + ], + "prompt_number": 2 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 13.3 Page No : 557" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "t = 0.001;\t\t\t#Thickness of the membrane in m\n", + "CA1 = 0.02;\t\t\t#Concentration of helium in the membrane at inner surface in k.mol/m**3\n", + "CA2 = 0.005;\t\t\t#Concentration of helium in the membrane at outer surface in k.mol/m**3\n", + "DAB = 10**-9;\t\t\t#Binary diffusion coefficient in m**2/s\n", + "\n", + "# Calculations\n", + "NAx = ((DAB*(CA1-CA2))/t)/10**-9;\t\t\t#Diffusion flux of helium through the plastic in k.mol/sm**2 *10**-9\n", + "\n", + "# Results\n", + "print 'Diffusion flux of helium through the plastic is %3.0f*10**-9 k.mol/sm**2'%(NAx)\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Diffusion flux of helium through the plastic is 15*10**-9 k.mol/sm**2\n" + ] + } + ], + "prompt_number": 3 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 13.4 Page No : 557" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "T = 273+25;\t\t\t#Temperature of Helium gas in K\n", + "p = 4;\t\t\t#Pressure of helium gas in bar\n", + "Di = 0.1;\t\t\t#Inner diamter of wall in m\n", + "Do = 0.003;\t\t\t#Outer diamter of wall in m\n", + "DAB = (0.4*10**-13);\t\t\t#Binary diffusion coefficient in m**2/s\n", + "S = (0.45*10**-3);\t\t\t#S value for differentiation\n", + "\n", + "# Calculations\n", + "A = (3.14*Di**2);\t\t\t#Area in m**2\n", + "V = (3.14*Di**3)/6;\t\t\t#Volume in m**3\n", + "R = 0.08316\t\t\t#Gas consmath.tant in m**3 bar/kmol.K\n", + "d = ((-6*R*T*DAB*S*p)/(Do*Di))/10**-11;\t\t\t#Decrease of pressure with time in bar/s*10**-11\n", + "\n", + "# Results\n", + "print 'Initial rate of leakage for the system is provided by the decrease of pressure \\\n", + " with time which is %3.2f*10**-11 bar/s'%(d)\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Initial rate of leakage for the system is provided by the decrease of pressure with time which is -3.57*10**-11 bar/s\n" + ] + } + ], + "prompt_number": 4 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 13.5 Page No : 558" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math\n", + "\n", + "# Variables\n", + "po2 = 2;\t\t\t#Pressure of O2 in bar\n", + "Di = 0.025;\t\t\t#inside diamter of the pipe in m\n", + "L = 0.0025;\t\t\t#Wall thickness in m\n", + "a = (0.21*10**-2);\t\t\t#Diffusivity of O2 in m**2/s\n", + "S = (3.12*10**-3);\t\t\t#Solubility of O2 in k.mol/m**3.bar\n", + "DAB = (0.21*10**-9);\t\t\t#Binary diffusion coefficient in m**2/s\n", + "\n", + "# Calculations\n", + "CAi = (S*po2);\t\t\t#Concentration of O2 on inside surface in kmol/m**3\n", + "RmA = ((math.log((Di+(2*L))/Di))/(2*3.14*DAB));\t\t\t#Diffusion resismath.tance in sm**2\n", + "Loss = (CAi/RmA)/10**-11;\t\t\t#Loss of O2 by diffusion per meter length of pipe *10**-11\n", + "\n", + "# Results\n", + "print 'Loss of O2 by diffusion per meter length of pipe is %3.2f*10**-11 kmol/s'%(Loss)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Loss of O2 by diffusion per meter length of pipe is 4.51*10**-11 kmol/s\n" + ] + } + ], + "prompt_number": 6 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 13.6 Page No : 560" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "p = 1;\t\t\t#Pressure of system in atm\n", + "T = 25+273;\t\t\t#Temperature of system in K\n", + "pco2 = (190./760);\t\t\t#Partial pressure of CO2 at one end in atm\n", + "pco2o = (95./760);\t\t\t#Partial pressure of CO2 at other end in atm\n", + "DAB = (0.16*10**-4);\t\t\t#Binary diffusion coefficient in m**2/s from Table 13.3\n", + "R = 0.08205\t\t\t#Gas constant in m**3 atm/kmol.K\n", + "\n", + "# Calculations\n", + "NAx = (DAB*(pco2-pco2o))/(R*T*p);\t\t\t#Equimolar counter diffusion in kmol/m**2s\n", + "M = (NAx*3.14*(0.05**2/4)*3600);\t\t\t#Mass transfer rate in kmol/h\n", + "MCO2 = (M*44)/10**-5;\t\t\t#Mass flow rate of CO2 in kg/h *10**-5\n", + "Mair = (29*-M)/10**-5;\t\t\t#Mass flow rate of air in kg/h *10**-5\n", + "\n", + "# Results\n", + "print 'Mass transfer rate of CO2 is %3.2f*10**-5 kg/h Mass transfer rate of air is %3.2f*10**-5 kg/h'%(MCO2,Mair)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Mass transfer rate of CO2 is 2.54*10**-5 kg/h Mass transfer rate of air is -1.68*10**-5 kg/h\n" + ] + } + ], + "prompt_number": 7 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 13.7 Page No : 563" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math\n", + "# Variables\n", + "T = 27+273;\t\t\t#Temperature of water in K\n", + "D = 0.02;\t\t\t#Diameter of the tube in m\n", + "L = 0.4;\t\t\t#Length of the tube in m\n", + "DAB = (0.26*10**-4);\t\t\t#Diffusion coefficient in m**2/s\n", + "\n", + "# Calculations\n", + "p = 1.0132;\t\t\t#Atmospheric pressure in bar\n", + "pA1 = 0.03531;\t\t\t#Vapour pressure in bar\n", + "m = ((p*10**5*3.14*(D/2)**2*18*DAB)/(8316*T*L))*(1000*3600)*math.log(p/(p-pA1));\t\t\t#Diffusion rate of water in gram per hour\n", + "\n", + "# Results\n", + "print 'Diffusion rate of water is %3.4f gram per hour'%(m)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Diffusion rate of water is 0.0019 gram per hour\n" + ] + } + ], + "prompt_number": 8 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 13.8 Page No : 564" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math\n", + "# Variables\n", + "T = 25+273;\t\t\t#Temperature of water in K\n", + "D = 0.02;\t\t\t#Diameter of the tube in m\n", + "L = 0.08;\t\t\t#Length of the tube in m\n", + "m = (8.54*10**-4);\t\t\t#Diffusion coefficient in kg/h\n", + "\n", + "# Calculations\n", + "p = 1.0132;\t\t\t#Atmospheric pressure in bar\n", + "pA1 = 0.03165;\t\t\t#Vapour pressure in bar\n", + "DAB = (((m/3600)*8316*T*L)/(p*10**5*3.14*(D/2)**2*18*math.log(p/(p-pA1))*10**2))/10**-4;\t\t\t#Diffusion coefficient of water in m**2/s *10**-4\n", + "\n", + "# Calculations\n", + "print 'Diffusion coefficient of water is %3.3f*10**-4 m**2/s'%(DAB)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Diffusion coefficient of water is 0.259*10**-4 m**2/s\n" + ] + } + ], + "prompt_number": 9 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 13.9 Page No : 569" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "CAs = 0.02;\t\t\t#Carbon mole fraction\n", + "CAo = 0.004;\t\t#Content of steel\n", + "CA = 0.012;\t\t\t#Percet of depth\n", + "d = 0.001;\t\t\t#Depth in m\n", + "H = (6*10**-10);\t#Diffusivity of carbon in m**2/s\n", + "\n", + "# Calculations\n", + "X = (CA-CAs)/(CAo-CAs);\t\t\t#Calculation for erf function\n", + "n = 0.48; \t\t\t#erf(n) = 0.5; n = 0.48\n", + "t = ((d/(n*2.))**2/(3600.*H))*3600;\t\t\t#Time required to elevate the carbon content of steel in s\n", + "\n", + "\n", + "# Results\n", + "print 'Time required to elevate the carbon content of steel is %3.2f s'%(t)\n", + "\n", + "\n", + "# note : rounding error." + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Time required to elevate the carbon content of steel is 1808.45 s\n" + ] + } + ], + "prompt_number": 1 + } + ], + "metadata": {} + } + ] +}
\ No newline at end of file diff --git a/Fundamentals_Of_Engineering_Heat_And_Mass_Transfer/ch14.ipynb b/Fundamentals_Of_Engineering_Heat_And_Mass_Transfer/ch14.ipynb new file mode 100755 index 00000000..45a0661c --- /dev/null +++ b/Fundamentals_Of_Engineering_Heat_And_Mass_Transfer/ch14.ipynb @@ -0,0 +1,525 @@ +{ + "metadata": { + "name": "", + "signature": "sha256:484a2df5b3762980a76b55ab94f7de4a4a7924fa2fa9ffe86e0603d655f531d8" + }, + "nbformat": 3, + "nbformat_minor": 0, + "worksheets": [ + { + "cells": [ + { + "cell_type": "heading", + "level": 1, + "metadata": {}, + "source": [ + "Chapter 14 : Convective Mass Transfer" + ] + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 14.1 Page No : 574" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math \n", + "\n", + "# Variables\n", + "D = 0.025;\t\t\t #Diameter of the cylinder in m\n", + "R = (2*10**-6);\t\t\t#Rate of sublime in kg/s\n", + "C = (6*10**-6);\t\t\t#Saturated vapour concentration in kmol/m**3\n", + "W = 128;\t\t\t #Molecular weight in kg/kmol\n", + "\n", + "# Calculations\n", + "q = (R/W);\t\t\t #Molar transfer rate in k.mol/sm\n", + "h = (q/(math.pi*D*C));\t\t\t#Convective mass transfer coefficient in m/s\n", + "\n", + "# Results\n", + "print 'Convective mass transfer coefficient is %3.3f m/s'%(h)" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Convective mass transfer coefficient is 0.033 m/s\n" + ] + } + ], + "prompt_number": 1 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 14.2 Page No : 576" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math\n", + "# Variables\n", + "pA = -0.9;\t\t\t#Partial pressure of water vapour in atm\n", + "t = 0.0025;\t\t\t#Boundary layer thickness in m\n", + "\n", + "# Calculations\n", + "y = 0;\n", + "pAs1 = math.exp(-33.35*y)-0.9;\t\t\t#Partial pressure in atm\n", + "y = t;\n", + "pAs2 = math.exp(-33.35*y)-0.9;\t\t\t#Partial pressure in atm\n", + "#partial derivative of pA wrt y is -33.35exp(y)-0.9\n", + "x = 0;\n", + "X = (-33.35*math.exp(x))-pA;\t\t\t#Partial derivative value at x = 0\n", + "DAB = (0.26*10**-4)\t\t\t#DAB value in m**2/s\n", + "h = (DAB*X)/(pAs2-pAs1);\t\t\t#Local mass transfer coefficient in m/s\n", + "\n", + "# Results\n", + "print 'Local mass transfer coefficient is %3.3f m/s'%(h)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Local mass transfer coefficient is 0.011 m/s\n" + ] + } + ], + "prompt_number": 7 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 14.3 Page No : 583" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "T = 27;\t\t\t#Temperature of dry air in degree C\n", + "p = 1;\t\t\t#Pressure of dry air in atm\n", + "L = 0.5;\t\t\t#Length of the plate in m\n", + "v = 50;\t\t\t#Velocity in m/s\n", + "\n", + "# Calculations\n", + "DAB = (0.26*10**-4)\t\t\t#DAB value in m**2/s\n", + "p = 1.16;\t\t\t#Density in kg/m**3\n", + "u = (184.6*10**-7);\t\t\t#Dynamic viscosity in N.s/m**2\n", + "Pr = 0.707;\t\t\t#Prantl number\n", + "Sc = (u/(p*DAB));\t\t\t#Schmidt number\n", + "Re = (p*v*L)/u;\t\t\t#Reynolds number\n", + "jm = (0.0296*(Re**(-1./5)));\t\t\t#jm value\n", + "h = (jm*v)/Sc**(2./3);\t\t\t#Mass transfer coefficient of water vapour in m/s\n", + "\n", + "# Results\n", + "print 'Mass transfer coefficient of water vapour is %3.3f m/s'%(h)\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Mass transfer coefficient of water vapour is 0.118 m/s\n" + ] + } + ], + "prompt_number": 3 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 14.4 Page No : 583" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "T = 27;\t\t\t#Temperature of swimming pool in degree C\n", + "h = 0.4;\t\t\t#Relative humidity\n", + "v = 2;\t\t\t#Speed of wind in m/s\n", + "v1 = (15.89*10**-6);\t\t\t#Kinematic viscosity in m**2/s\n", + "p = 0.0436;\t\t\t#Density in kg/m**3\n", + "DAB = (0.26*10**-4)\t\t\t#DAB value in m**2/s\n", + "L = 15;\t\t\t#Length in m\n", + "\n", + "\n", + "# Calculations\n", + "Sc = (v1/DAB);\t\t\t#Schmidt number\n", + "Re = (v*L)/v1;\t\t\t#Reynolds number\n", + "ShL = (((0.037*Re**(4./5))-870)*Sc**(1./3));\t\t\t#Equivalent Schmidt number\n", + "h1 = (ShL*(DAB/L))/10**-3;\t\t\t#Mass transfer coefficient for evaporation in mm/s\n", + "\n", + "# Results\n", + "print 'Mass transfer coefficient for evaporation is %3.1f*10**-3 m/s'%(h1)\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Mass transfer coefficient for evaporation is 4.4*10**-3 m/s\n" + ] + } + ], + "prompt_number": 5 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 14.5 Page No : 585" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "T = 25;\t\t\t#Temperature of air in degree C\n", + "v = 3;\t\t\t#Velocity im m/s\n", + "D = 0.01;\t\t\t#Diameter of tube in m\n", + "L = 1;\t\t\t#Length of tube in m\n", + "\n", + "# Calculations\n", + "v1 = (15.7*10**-6);\t\t\t#Kinematic viscosity in m**2/s\n", + "DAB = (0.62*10**-5)\t\t\t#DAB value in m**2/s\n", + "Re = (v*D)/v1;\t\t\t#Reynolds number\n", + "Sh = 3.66;\t\t\t#Schmidt number\n", + "h = (Sh*DAB)/D;\t\t\t#Average mass transfer coefficient in m/s\n", + "\n", + "# Results\n", + "print 'Average mass transfer coefficient is %3.5f m/s'%(h)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Average mass transfer coefficient is 0.00227 m/s\n" + ] + } + ], + "prompt_number": 6 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 14.6 Page No : 586" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "T = 25;\t\t\t#Temperature of air in degree C\n", + "v = 5;\t\t\t#Velocity in m/s\n", + "D = 0.03;\t\t\t#Diameter of tube in m\n", + "DAB = (0.82*10**-5)\t\t\t#DAB value in m**2/s\n", + "\n", + "# Calculations\n", + "v1 = (15.7*10**-6);\t\t\t#Kinematic viscosity in m**2/s\n", + "Sc = (v1/DAB);\t\t\t#Schnidt number\n", + "Re = (v*D)/v1;\t\t\t#Reynolds number\n", + "h = (0.023*Re**(4./5)*Sc**(1./3)*DAB)/D;\t\t\t#Mass transfer coefficient in m/s\n", + "\n", + "# Results\n", + "print 'Mass transfer coefficient is %3.4f m/s'%(h)\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Mass transfer coefficient is 0.0119 m/s\n" + ] + } + ], + "prompt_number": 8 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 14.7 Page No : 589" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math\n", + "# Variables\n", + "Ta = 40.+273;\t\t\t#Temperature of air in K\n", + "w = 100.;\t\t\t #Molecular weight in kg/k.mol\n", + "H = 120.;\t\t\t #Latent heat of vapourisation of volatile liquid in kJ/kg\n", + "p = 3530.;\t\t\t #Saturated vapour pressure in N/m**2\n", + "DAB = (0.2*10**-4);\t\t#DAB value in m**2/s\n", + "\n", + "# Calculations\n", + "p1 = 1.16;\t\t\t#Density in kg/m**2\n", + "Cp = 1.007;\t\t\t#Specific heat in J/kg.K\n", + "a = (22.5*10**-6);\t\t\t#Diffusivity in m**2/s\n", + "X = ((H*100*p*10**-3)/(8.315*p1*Cp*(a/DAB)**(2./3)));\t\t\t#X value for temperature\n", + "T = (Ta+math.sqrt((Ta**2-(4*X))))*0.5;\t\t\t#Temperature in K\n", + "\n", + "# Results\n", + "print 'Steady state temperature of cold water inside the pot is %3.1f K'%(T)\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Steady state temperature of cold water inside the pot is 299.5 K\n" + ] + } + ], + "prompt_number": 9 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 14.8 Page No : 590" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "T = 22. + 273;\t\t\t#Thermometer reading in K\n", + "\n", + "# Calculations\n", + "p = 2617;\t\t\t#Pressure in N/m**2\n", + "hfg = 2449;\t\t\t#Enthalpy in kJ/kg\n", + "p1 = (p*18)/(8315*T);\t\t\t#Density in kg/m**3\n", + "p2 = (1.0132*10**5)/(287*T);\t\t\t#Density in kg/m**3\n", + "Cp = 1.008;\t\t\t#Specific heat in kJ/kg.K\n", + "a = (26.2*10**-6);\t\t\t#Diffusivity in m**2/s\n", + "DAB = (0.26*10**-4);\t\t\t#DAB value in m**2/s\n", + "Ts = ((T-273)+((hfg*1000*p1)/(p2*Cp*1000)));\t\t\t#True air temperature in degree C\n", + "\n", + "# Results\n", + "print 'True air temperature is %3.2f degree C'%(Ts)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "True air temperature is 60.99 degree C\n" + ] + } + ], + "prompt_number": 10 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 14.9 Page No : 591" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "T = 50.;\t\t\t#Temperature of air stream in degree C\n", + "Tb = 22.;\t\t\t#Bulb temperature in degree C\n", + "\n", + "# Calculations\n", + "Tf = (T+Tb)/2;\t\t\t#Film temperature in degree C\n", + "p = 1.14;\t\t\t#Density in kg/m**3\n", + "Cp = 1.006;\t\t\t#Specific heat in J/kg.K\n", + "Pr = 0.7;\t\t\t#Prantl number\n", + "u = (2*10**-5);\t\t\t#Dynamic viscosity in Ns/m**2\n", + "DAB = (0.26*10**-4);\t\t\t#DAB value in m**2/s\n", + "Sc = (u/(p*DAB));\t\t\t#Schmidt nuber\n", + "Le = (Sc/Pr);\t\t\t#Lewis number\n", + "p1 = 0.01920;\t\t\t#Density in kg/m**3\n", + "hfg = 2449;\t\t\t#Enthalpy in kJ/kg\n", + "pA = 0.0064;\t\t\t#Density in kg/m**3\n", + "psat = (1./12.23);\t\t\t#Saturation density in kg/m**3\n", + "RH = (pA/0.0817)*100;\t\t\t#Relative humidity\n", + "\n", + "# Results\n", + "print 'Relative humidity of the airstream is %3.2f percent'%(RH)\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Relative humidity of the airstream is 7.83 percent\n" + ] + } + ], + "prompt_number": 11 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 14.10 Page No : 592" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "Td = 27.;\t\t\t#Dry bulb teperature in degree C\n", + "Tw = 17.;\t\t\t#Wet bulb temperature in degree C\n", + "Pr = 0.74;\t\t\t#Prantl number\n", + "Sc = 0.6;\t\t\t#Schmidt number\n", + "Mv = 18.;\t\t\t#Molecular weight of vapour\n", + "Ma = 29.;\t\t\t#Molecular weight of air\n", + "Cp = 1004.;\t\t\t#Specific heat in J/kg.K\n", + "p = (1.0132*10**5);\t\t\t#Pressure in N/m**2\n", + "\n", + "# Calculations\n", + "pv2 = 1917;\t\t\t#Saturation presusre of air at 17 degree C in N/m**2\n", + "hfg = 2461;\t\t\t#Enthalpy in kJ/kg\n", + "w2 = (Mv*pv2)/(Ma*(p-pv2));\t\t\t#Weight in kg/kg of dry air\n", + "w1 = w2-((Cp*(Pr/Sc)**(2./3)*(Td-Tw))/(hfg*1000));\t\t\t#Specific humidity of air in kg/kg of dry air\n", + "\n", + "# Results\n", + "print 'Specific humidity of air is %3.5f kg/kg of dry air'%(w1)\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Specific humidity of air is 0.00728 kg/kg of dry air\n" + ] + } + ], + "prompt_number": 12 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 14.11 Page No : 592" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "T = 27.;\t\t \t#Temperature of swimming pool in degree C\n", + "Ts = 37.;\t\t\t#Surface temperature in degree C\n", + "h = 0.4;\t\t\t#Relative humidity\n", + "D1 = 5.;\t\t \t#Dimension of swimming pool in m\n", + "D2 = 15.;\t\t\t#Dimension of swimming pool in m\n", + "v = 2.;\t\t \t#Speed of wind in m/s\n", + "v1 = (15.89*10**-6);\t\t\t#Kinematic viscosity in m**2/s\n", + "p = 0.0436;\t\t\t #Density in kg/m**3\n", + "DAB = (0.26*10**-4)\t \t\t#DAB value in m**2/s\n", + "Sc = (v1/DAB);\t\t \t#Schmidt number\n", + "Re = (v*D2)/v1;\t\t \t#Reynolds number\n", + "ShL = (((0.037*Re**(4./5))-870)*Sc**(1./3));\t\t\t#Equivalent Schmidt number\n", + "h1 = (ShL*(DAB/D2));\t\t\t#Mass transfer coefficient for evaporation in m/s\n", + "\n", + "# Calculations\n", + "Psat = 3531.;\t\t\t#Partial pressure of water vapour in N/m**2\n", + "pi = (0.4*6221);\t\t\t#Saturation pressure of water vapour in N/m**2\n", + "pt = 101325.;\t\t\t#Total pressure of air in N/m**2\n", + "pAs = (18*Psat)/(8361*(T+273));\t\t\t#Density at the water surface in kg/m\n", + "pAi = (18*pi)/(8316*(T+273));\t\t\t#Density at the water surface in kg/m\n", + "n = round((h1*(pAs-pAi)*3600*24),);\t\t\t#Rate of evaporation of water in kg/m**2 day\n", + "L = (n*D1*D2);\t\t\t#Total water loss from the swimming pool in kg/day\n", + "\n", + "# Results\n", + "print 'Rate of evaporation of water is %3.1f kg/day'%(L)\n", + "\n", + "# there is a rounding off error in textbook." + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Rate of evaporation of water is 225.0 kg/day\n" + ] + } + ], + "prompt_number": 4 + }, + { + "cell_type": "code", + "collapsed": false, + "input": [], + "language": "python", + "metadata": {}, + "outputs": [] + } + ], + "metadata": {} + } + ] +}
\ No newline at end of file diff --git a/Fundamentals_Of_Engineering_Heat_And_Mass_Transfer/ch3.ipynb b/Fundamentals_Of_Engineering_Heat_And_Mass_Transfer/ch3.ipynb new file mode 100755 index 00000000..930ae930 --- /dev/null +++ b/Fundamentals_Of_Engineering_Heat_And_Mass_Transfer/ch3.ipynb @@ -0,0 +1,1535 @@ +{ + "metadata": { + "name": "", + "signature": "sha256:a4eb855d2f94bc4d3b88cc418db7aa787fc638da4c248a8ac28f23e0760aff9c" + }, + "nbformat": 3, + "nbformat_minor": 0, + "worksheets": [ + { + "cells": [ + { + "cell_type": "heading", + "level": 1, + "metadata": {}, + "source": [ + "Chapter 3 : OneDimensional Steady State Heat Conduction" + ] + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 3.1 Page No : 45" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "\n", + "\n", + "# Variables\n", + "l = 5;\t\t \t#Length of the wall in m\n", + "h = 4;\t\t\t #Height of the wall in m\n", + "L = 0.25;\t\t\t#Thickness of the wall in m\n", + "T = [110,40];\t\t#Temperature on the inner and outer surface in degree C\n", + "k = 0.7;\t\t\t#Thermal conductivity in W/m.K\n", + "x = 0.20;\t\t\t#Distance from the inner wall in m\n", + "\n", + "# Calculations\n", + "A = l*h;\t\t\t #Arear of the wall in m**2\n", + "Q = (k*A*(T[0]-T[1]))/L;\t \t\t#Heat transfer rate in W\n", + "T = (((T[1]-T[0])*x)/L)+T[0];\t\t\t#Temperature at interior point of the wall, 20 cm distant from the inner wall in degree C\n", + "\n", + "# Results\n", + "print 'a)Heat transfer rate is %i W \\n \\\n", + "b)Temperature at interior point of the wall, 20 cm distant from the inner wall is %i degree C'%(Q, T)\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "a)Heat transfer rate is 3920 W \n", + " b)Temperature at interior point of the wall, 20 cm distant from the inner wall is 54 degree C\n" + ] + } + ], + "prompt_number": 1 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 3.2 Page No : 48" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math \n", + "\n", + "# Variables\n", + "Di = 0.05;\t\t \t#Inner diameter of hollow cylinder in m\n", + "Do = 0.1;\t\t\t #Outer diameter of hollow cylinder in m\n", + "T = [200,100];\t\t\t#Inner and outer surface temperature in degree C\n", + "k = 70;\t\t\t #Thermal conductivity in W/m.K\n", + "\n", + "# Calculations\n", + "ro = (Do/2);\t\t\t#Outer radius of hollow cylinder in m\n", + "ri = (Di/2);\t\t\t#Inner radius of hollow cylinder in m\n", + "Q = ((2*3.14*k*(T[0]-T[1]))/(math.log(ro/ri)));\t\t\t#Heat transfer rate in W\n", + "r1 = (ro+ri)/2;\t\t\t#Radius at halfway between ro and ri in m\n", + "T1 = T[0]-((T[0]-T[1])*(math.log(r1/ri)/(math.log(ro/ri))));\t\t\t#Temperature of the point halfway between the inner and outer surface in degree C\n", + "\n", + "# Results\n", + "print 'Heat transfer rate is %3.1f W /m \\n \\\n", + "Temperature of the point halfway between the inner and outer surface is %3.1f degree C'%(Q,T1)\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Heat transfer rate is 63420.9 W /m \n", + " Temperature of the point halfway between the inner and outer surface is 141.5 degree C\n" + ] + } + ], + "prompt_number": 3 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 3.3 Page No : 51" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "Di = 0.1;\t\t\t#Inner diameter of hollow sphere in m\n", + "Do = 0.3;\t\t\t#Outer diameter of hollow sphere in m\n", + "k = 50. \t\t\t#Thermal conductivity in W/m.K\n", + "T = [300,100];\t\t\t#Inner and outer surface temperature in degree C\n", + "\n", + "# Calculations\n", + "ro = (Do/2);\t\t\t#Outer radius of hollow sphere in m\n", + "ri = (Di/2);\t\t\t#Inner radius of hollow sphere in m\n", + "Q = ((4*3.14*ro*ri*k*(T[0]-T[1]))/(ro-ri))/1000;\t\t\t#Heat transfer rate in W\n", + "r = ri+(0.25*(ro-ri));\t\t\t#The value at one-fourth way of te inner and outer surfaces in m\n", + "T = ((ro*(r-ri)*(T[1]-T[0]))/(r*(ro-ri)))+T[0];\t\t\t#Temperature at a point a quarter of the way between the inner and outer surfaces in degree C\n", + "\n", + "# Results\n", + "print 'Heat flow rate through the sphere is %3.2f kW \\n \\\n", + " Temperature at a point a quarter of the way between the inner and outer surfaces is %i degree C'%(Q,T)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Heat flow rate through the sphere is 9.42 kW \n", + " Temperature at a point a quarter of the way between the inner and outer surfaces is 200 degree C\n" + ] + } + ], + "prompt_number": 4 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 3.4 Page No : 55" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "L = 0.4;\t\t\t#Thickness of the furnace in m\n", + "T = [300,50];\t\t\t#Surface temperatures in degree C\n", + "#k = 0.005T-5*10**-6T**2\n", + "\n", + "# Calculations\n", + "q = ((1./L)*(((0.005/2)*(T[0]**2-T[1]**2))-((5*10**-6*(T[0]**3-T[1]**3))/3)));\t\t\t#Heat loss per square meter surface area in W/m**2\n", + "\n", + "# Results\n", + "print 'Heat loss per square meter surface area is %3.0f W/m**2'%(q)\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Heat loss per square meter surface area is 435 W/m**2\n" + ] + } + ], + "prompt_number": 1 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 3.5 Page No : 55" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "L = 0.2;\t\t\t #Thickness of the wall in m\n", + "T = [1000,200];\t\t\t#Surface temperatures in degree C\n", + "ko = 0.813;\t\t\t #Value of thermal conductivity at T = 0 in W/m.K\n", + "b = 0.0007158;\t\t\t#Temperature coefficient of thermal conductivity in 1./K\n", + "\n", + "# Calculations\n", + "km = ko*(1+((b*(T[0]+T[1]))/2));\t\t\t#Constant thermal conductivity in W/m.K\n", + "q = ((km*(T[0]-T[1]))/L);\t\t\t #Rate of heat flow in W/m**2\n", + "\n", + "# Results\n", + "print 'Rate of heat flow is %3.0f W/m**2'%(q)\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Rate of heat flow is 4649 W/m**2\n" + ] + } + ], + "prompt_number": 6 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 3.6 Page No : 58" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math\n", + "# Variables\n", + "r = [0.01,0.02];\t\t\t#Inner and outer radius of a copper cylinder in m\n", + "T = [310,290];\t\t\t#Inner and Outer surface temperature in degree C\n", + "ko = 371.9;\t\t\t#Value of thermal conductivity at T = 0 in W/m.K\n", + "b = (9.25*10**-5);\t\t\t#Temperature coefficient of thermal conductivity in 1./K\n", + "\n", + "# Calculations\n", + "Tm = ((T[0]-150)+(T[1]-150))/2;\t\t\t#Mean temperature in degree C\n", + "km = ko*(1-(b*Tm));\t\t\t #Constant thermal conductivity in W/m.K\n", + "q = ((2*3.14*km*(T[0]-T[1]))/math.log(r[1]/r[0]))/1000;\t\t\t#Heat loss per unit length in kW/m\n", + "\n", + "# Results\n", + "print 'Heat loss per unit length is %3.2f kW/m'%(q)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Heat loss per unit length is 66.45 kW/m\n" + ] + } + ], + "prompt_number": 7 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 3.8 Page No : 63" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "L1 = 0.5;\t\t \t#Thickness of the wall in m\n", + "k1 = 1.4;\t\t\t #Thermal conductivity in W/m.K\n", + "k2 = 0.35;\t\t\t #Thermal conductivity of insulating material in W/m.K\n", + "q = 1450.;\t\t\t #Heat loss per square metre in W\n", + "T = [1200,15];\t\t\t#Inner and outer surface temperatures in degree C\n", + "\n", + "# Calculations\n", + "L2 = (((T[0]-T[1])/q)-(L1/k1))*k2;\t\t\t#Thickness of the insulation required in m\n", + "\n", + "# Results\n", + "print 'Thickness of the insulation required is %3.3f m'%(L2)\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Thickness of the insulation required is 0.161 m\n" + ] + } + ], + "prompt_number": 1 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 3.9 Page No : 64" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "L1 = 0.006; \t\t\t#Thickness of each glass sheet in m\n", + "L2 = 0.002;\t \t\t#Thickness of air gap in m\n", + "Tb = -20;\t\t \t#Temperature of the air inside the room in degree C\n", + "Ta = 30;\t\t\t #Ambient temperature of air in degree C\n", + "ha = 23.26;\t\t\t #Heat transfer coefficient between glass and air in W/m**2.K\n", + "kglass = 0.75;\t\t\t#Thermal conductivity of glass in W/m.K\n", + "kair = 0.02;\t\t\t#Thermal conductivity of air in W/m.K\n", + "\n", + "# Calculations\n", + "q = ((Ta-Tb)/((1./ha)+(L1/kglass)+(L2/kair)+(L1/kglass)+(1./ha)));\t\t\t#Rate of heat leaking into the room per unit area of the door in W/m**2\n", + "\n", + "# Results\n", + "print 'Rate of heat leaking into the room per unit area of the door is %3.1f W/m**2'%(q)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Rate of heat leaking into the room per unit area of the door is 247.5 W/m**2\n" + ] + } + ], + "prompt_number": 13 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 3.10 Page No : 65" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "LA = 0.05;\t\t\t#Length of section A in m\n", + "LB = 0.1;\t\t\t#Length of section A in m\n", + "LC = 0.1;\t\t\t#Length of section A in m\n", + "LD = 0.05;\t\t\t#Length of section A in m\n", + "LE = 0.05;\t\t\t#Length of section A in m\n", + "kA = 50;\t\t\t#Thermal conductivity of section A in W/m.K\n", + "kB = 10;\t\t\t#Thermal conductivity of section B in W/m.K\n", + "kC = 6.67;\t\t\t#Thermal conductivity of section C in W/m.K\n", + "kD = 20;\t\t\t#Thermal conductivity of section D in W/m.K\n", + "kE = 30;\t\t\t#Thermal conductivity of section E in W/m.K\n", + "Aa = 1;\t\t\t#Area of section A in m**2\n", + "Ab = 0.5;\t\t\t#Area of section B in m**2\n", + "Ac = 0.5;\t\t\t#Area of section C in m**2\n", + "Ad = 1;\t\t\t#Area of section D in m**2\n", + "Ae = 1;\t\t\t#Area of section E in m**2\n", + "T = [800,100];\t\t\t#Temperature at inlet and outlet temperatures in degree C\n", + "\n", + "# Calculations\n", + "Ra = (LA/(kA*Aa)); \t\t\t#Thermal Resistance of section A in K/W\n", + "Rb = (LB/(kB*Ab));\t \t\t#Thermal Resistance of section B in K/W\n", + "Rc = (LC/(kC*Ac));\t\t \t#Thermal Resistance of section C in K/W\n", + "Rd = (LD/(kD*Ad));\t\t\t #Thermal Resistance of section D in K/W\n", + "Re = (LE/(kE*Ae));\t\t \t#Thermal Resistance of section E in K/W\n", + "Rf = ((Rb*Rc)/(Rb+Rc));\t\t\t#Equivalent resistance of section B and section C in K/W\n", + "R = Ra+Rf+Rd+Re;\t\t\t #Equivalent resistance of all sections in K/W\n", + "Q = ((T[0]-T[1])/R)/1000;\t\t\t#Heat transfer through the composite wall in kW\n", + "\n", + "# Results\n", + "print 'Heat transfer through the composite wall is %3.1f kW'%(Q)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Heat transfer through the composite wall is 40.8 kW\n" + ] + } + ], + "prompt_number": 14 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 3.11 Page No : 66" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "T1 = 2000;\t\t\t#Temperature of hot gas in degree C\n", + "Ta = 45;\t\t\t#Room air temperature in degree C\n", + "Qr1 = 23.260;\t\t\t#Heat flow by radiation from gases to inside surface of the wall in kW/m**2\n", + "h = 11.63;\t\t\t#Convective heat transfer coefficient in W/m**2.\n", + "C = 58;\t\t\t#Thermal conductance of the wall in W/m**2.K\n", + "Q = 9.3;\t\t\t#Heat flow by radiation from external surface to the surrounding in kW.m**2\n", + "T2 = 1000;\t\t\t#Interior wall temperature in degree C\n", + "\n", + "# Calculations\n", + "qr1 = Qr1;\t\t\t#Haet by radiation in kW/m**2\n", + "qc1 = h*((T1-T2)/1000);\t\t\t#Heat by conduction in kW/m**2\n", + "q = qc1+qr1;\t\t\t#Total heat entering the wall in kW/m**2\n", + "R = (1./C);\t\t\t#Thermal resistance in m**2.K/W\n", + "T3 = T2-(q*R*1000);\t\t\t#External wall temperature in degree C\n", + "Ql = q-Q;\t\t\t#Heat loss due to convection kW/m**2\n", + "h4 = (Ql*1000)/(T3-Ta);\t\t\t#Convective conductance in W/m**2.K\n", + "\n", + "# Results\n", + "print 'The surface temperature is %i degree C \\n \\\n", + "The convective conductance is %3.1f W/m**2.K'%(T3,h4)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "The surface temperature is 398 degree C \n", + " The convective conductance is 72.4 W/m**2.K\n" + ] + } + ], + "prompt_number": 2 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 3.12 Page No : 67" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "L1 = 0.125;\t\t\t#Thickness of fireclay layer in m\n", + "L2 = 0.5;\t\t\t#Thickness of red brick layer in m\n", + "T = [1100,50];\t\t\t#Temperatures at inside and outside the furnaces in degree C\n", + "k1 = 0.533;\t\t\t#Thermal conductivity of fireclay in W/m.K\n", + "k2 = 0.7;\t\t\t#Thermal conductivity of red brick in W/m.K\n", + "\n", + "# Calculations\n", + "R1 = (L1/k1);\t\t\t#Resismath.tance of fireclay per unit area in K/W\n", + "R2 = (L2/k2);\t\t\t#Resistance of red brick per unit area in K/W\n", + "R = R1+R2;\t\t\t#Total resistance in K/W\n", + "q = (T[0]-T[1])/R;\t\t\t#Heat transfer in W/m**2\n", + "T2 = T[0]-(q*R1);\t\t\t#Temperature in degree C\n", + "T3 = T[1]+(q*R2*0.5);\t\t\t#Temperature at the interface between the two layers in degree C\n", + "km = 0.113+(0.00023*((T2+T3)/2));\t\t\t#Mean thermal conductivity in W/m.K\n", + "x = ((T2-T3)/q)*km;\t\t\t#Thickness of diatomite in m\n", + "\n", + "# Results\n", + "print 'Amount of heat loss is %3.1f W/m**2 \\n \\\n", + "Thickness of diatomite is %3.4f m'%(q,x )\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Amount of heat loss is 1106.7 W/m**2 \n", + " Thickness of diatomite is 0.0932 m\n" + ] + } + ], + "prompt_number": 17 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 3.13 Page No : 70" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math\n", + "# Variables\n", + "Di = 0.1;\t\t\t#I.D of the pipe in m\n", + "L = 0.01;\t\t\t#Thickness of the wall in m\n", + "L1 = 0.03;\t\t\t#Thickness of insulation in m\n", + "Ta = 85;\t\t\t#Temperature of hot liquid in degree C\n", + "Tb = 25;\t\t\t#Temperature of surroundings in degree C\n", + "k1 = 58;\t\t\t#Thermal conductivity of steel in W/m.K\n", + "k2 = 0.2;\t\t\t#Thermal conductivity of insulating material in W/m.K\n", + "ha = 720;\t\t\t#Inside heat transfer coefficient in W/m**2.K\n", + "hb = 9;\t\t\t #Outside heat transfer coefficient in W/m**2.K\n", + "D2 = 0.12;\t\t\t#Inner diameter in m\n", + "r3 = 0.09;\t\t\t#Radius in m\n", + "\n", + "# Calculations\n", + "q = ((2*3.14*(Ta-Tb))/((1./(ha*(Di/2)))+(1./(hb*r3))+(math.log(D2/Di)/k1)+(math.log(r3/(D2/2))/k2)));\t\t\t#Heat loss fro an insulated pipe in W/m\n", + "\n", + "# Results\n", + "print 'Heat loss from an insulated pipe is %3.2f W/m'%(q)" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Heat loss from an insulated pipe is 114.43 W/m\n" + ] + } + ], + "prompt_number": 3 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 3.14 Page No : 71" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math\n", + "\n", + "# Variables\n", + "Di = 0.1;\t\t\t#I.D of the pipe in m\n", + "Do = 0.11;\t\t\t#O.D of the pipe in m\n", + "L = 0.005;\t\t\t#Thickness of the wall in m\n", + "k1 = 50;\t\t\t#Thermal conductivity of steel pipe line in W/m.K\n", + "k2 = 0.06;\t\t\t#Thermal conductivity of first insulating material in W/m.K\n", + "k3 = 0.12;\t\t\t#Thermal conductivity of second insulating material in W/m.K\n", + "T = [250,50];\t\t\t#Temperature at inside tube surface and outside surface of insulation in degree C\n", + "r3 = 0.105;\t\t\t#Radius of r3 in m as shown in fig.3.14 on page no.71\n", + "r4 = 0.155;\t\t\t#Radius of r4 in m as shown in fig.3.14 on page no.71\n", + "\n", + "# Calculations\n", + "r1 = (Di/2);\t\t\t#Radius of the pipe in m\n", + "r2 = (Do/2);\t\t\t#Radius of the pipe in m\n", + "q = ((2*3.14*(T[0]-T[1]))/(((math.log(r2/r1))/k1)+((math.log(r3/r2))/k2)+((math.log(r4/r3))/k3)));\t\t\t#Loss of heat per metre length of pipe in W/m\n", + "T3 = ((q*math.log(r4/r3))/(2*3.14*k3))+T[1];\t\t\t#Interface temperature in degree C\n", + "\n", + "# Results\n", + "print 'Loss of heat per metre length of pipe is %3.1f W/m \\n \\\n", + "Interface temperature is %3.1f degree C'%(q,T3)" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Loss of heat per metre length of pipe is 89.6 W/m \n", + " Interface temperature is 96.3 degree C\n" + ] + } + ], + "prompt_number": 21 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 3.15 Page No : 72" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math\n", + "\n", + "# Variables\n", + "Di = 0.1;\t\t\t#I.D of the pipe in m\n", + "Do = 0.11;\t\t\t#O.D of the pipe in m\n", + "L = 0.005;\t\t\t#Thickness of the wall in m\n", + "k1 = 50;\t\t\t#Thermal conductivity of steel pipe line in W/m.K\n", + "k3 = 0.06;\t\t\t#Thermal conductivity of first insulating material in W/m.K\n", + "k2 = 0.12;\t\t\t#Thermal conductivity of second insulating material in W/m.K\n", + "T = [250,50];\t\t\t#Temperature at inside tube surface and outside surface of insulation in degree C\n", + "r3 = 0.105;\t\t\t#Radius of r3 in m as shown in fig.3.14 on page no.71\n", + "r4 = 0.155;\t\t\t#Radius of r4 in m as shown in fig.3.14 on page no.71\n", + "\n", + "# Calculations\n", + "r1 = (Di/2);\t\t\t#Radius of the pipe in m\n", + "r2 = (Do/2);\t\t\t#Radius of the pipe in m\n", + "q = ((2*3.14*(T[0]-T[1]))/(((math.log(r2/r1))/k1)+((math.log(r3/r2))/k2)+((math.log(r4/r3))/k3)));\t\t\t#Loss of heat per metre length of pipe in W/m\n", + "\n", + "# Results\n", + "print 'Loss of heat per metre length of pipe is %3.2f W/m'%(q)\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Loss of heat per metre length of pipe is 105.71 W/m\n" + ] + } + ], + "prompt_number": 22 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 3.16 Page No : 73" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math\n", + "\n", + "# Variables\n", + "D1 = 0.1;\t\t\t#O.D of the pipe in m\n", + "P = 1373;\t\t\t#Pressure of saturated steam in kPa\n", + "D2 = 0.2;\t\t\t#Diameter of magnesia in m\n", + "k1 = 0.07;\t\t\t#Thermal conductivity of magnesia in W/m.K\n", + "k2 = 0.08;\t\t\t#Thermal conductivity of asbestos in W/m.K\n", + "D3 = 0.25;\t\t\t#Diameter of asbestos in m\n", + "T3 = 20;\t\t\t#Temerature under the canvas in degree C\n", + "t = 12;\t\t\t #Time for condensation in hours\n", + "l = 150;\t\t\t#Lemgth of pipe in m\n", + "T1 = 194.14;\t\t\t#Saturation temperature of steam in degree C from Table A.6 (Appendix A) at 1373 kPa on page no. 643\n", + "hfg = 1963.15;\t\t\t#Latent heat of steam in kJ/kg from Table A.6 (Appendix A) at 1373 kPa on page no. 643\n", + "\n", + "# Calculations\n", + "r1 = (D1/2);\t\t\t#Radius of the pipe in m\n", + "r2 = (D2/2);\t\t\t#Radius of magnesia in m\n", + "r3 = (D3/2);\t\t\t#Radius of asbestos in m\n", + "Q = (((2*3.14*l*(T1-T3))/((math.log(r2/r1)/k1)+(math.log(r3/r2)/k2)))*(3600./1000));\t\t\t#Heat transfer rate in kJ/h\n", + "m = (Q/hfg);\t\t\t#Mass of steam condensed per hour\n", + "m1 = (m*t);\t\t\t#Mass of steam condensed in 12 hours\n", + "\n", + "# Results\n", + "print 'Mass of steam condensed in 12 hours is %3.2f kg'%(m1)\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Mass of steam condensed in 12 hours is 284.43 kg\n" + ] + } + ], + "prompt_number": 24 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 3.17 Page No : 74" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "D1 = 0.1;\t\t\t#I.D of the first pipe in m\n", + "D2 = 0.3;\t\t\t#O.D of the first pipe in m\n", + "k1 = 70;\t\t\t#Thermal conductivity of first material in W/m.K\n", + "D3 = 0.4;\t\t\t#O.D of the second pipe in m\n", + "k2 = 15;\t\t\t#Thermal conductivity of second material in W/m.K\n", + "T = [300,30];\t\t\t#Inside and outside temperatures in degree C\n", + "\n", + "# Calculations\n", + "r1 = (D1/2);\t\t\t#Inner Radius of first pipe in m\n", + "r2 = (D2/2);\t\t\t#Outer Radius of first pipe in m\n", + "r3 = (D3/2);\t\t\t#Radius of second pipe in m\n", + "Q = ((4*3.14*(T[0]-T[1]))/(((r2-r1)/(k1*r1*r2))+((r3-r2)/(k2*r2*r3))))/1000;\t\t\t#Rate of heat flow through the sphere in kW\n", + "\n", + "# Results\n", + "print 'Rate of heat flow through the sphere is %3.2f kW'%(Q)\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Rate of heat flow through the sphere is 11.24 kW\n" + ] + } + ], + "prompt_number": 26 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 3.18 Page No : 77" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math\n", + "\n", + "# Variables\n", + "Di = 0.1;\t\t\t#I.D of a steam pipe in m\n", + "Do = 0.25;\t\t\t#I.D of a steam pipe in m\n", + "k = 1.;\t\t\t#Thermal conductivity of insulating material in W/m.K\n", + "T = [200.,20];\t\t\t#Steam temperature and ambient temperatures in degree C\n", + "h = 8.;\t\t\t#Convective heat transfer coefficient between the insulation surface and air in W/m**2.K\n", + "\n", + "# Calculations\n", + "ri = (Di/2);\t\t\t#Inner Radius of steam pipe in m\n", + "ro = (Do/2);\t\t\t#Outer Radius of steam pipe in m\n", + "rc = (k/h)*100;\t\t\t#Critical radius of insulation in cm\n", + "q = ((T[0]-T[1])/((math.log(ro/ri)/(2*3.14*k)+(1./(2*3.14*ro*h)))));\t\t\t#Heat loss per metre of pipe at critical radius in W/m\n", + "Ro = (q/(2*3.14*ro*h))+T[1];\t\t\t#Outer surface temperature in degree C\n", + "\n", + "# Results\n", + "print 'Heat loss per metre of pipe at critical radius is %i W/m \\n \\\n", + "Outer surface temperature is %3.2f degree C'%(q,Ro)\n", + "\n", + "# Note : Answer in book is wrong. Please check manually." + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Heat loss per metre of pipe at critical radius is 589 W/m \n", + " Outer surface temperature is 113.93 degree C\n" + ] + } + ], + "prompt_number": 8 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 3.19 Page No : 78" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math\n", + "\n", + "# Variables\n", + "Di = 0.001;\t\t \t#Diameter of copper wire in m\n", + "t = 0.001;\t\t \t#Thickness of insulation in m;\n", + "To = 20;\t\t \t#Temperature of surrondings in degree C\n", + "Ti = 80;\t\t \t#Maximum temperature of the plastic in degree C\n", + "kcopper = 400;\t\t\t#Thermal conductivity of copper in W/m.K\n", + "kplastic = 0.5;\t\t\t#Thermal conductivity of plastic in W/m.K\n", + "h = 8;\t \t\t#Heat transfer coefficient in W/m**2.K\n", + "p = (3*10**-8);\t\t\t#Specific electric resistance of copper in Ohm.m\n", + "\n", + "# Calculations\n", + "r = (Di/2);\t\t\t#Radius of copper tube in m\n", + "ro = (r+t);\t\t\t#Radius in m \n", + "R = (p/(3.14*r*r*0.01));\t\t\t#Electrical resistance per meter length in ohm/m\n", + "Rth = ((1./(2*3.14*ro*h))+(math.log(ro/r)/(2*3.14*kplastic)));\t\t\t#Thermal resistance of convection film insulation per metre length \n", + "Q = ((Ti-To)/Rth);\t\t\t#Heat transfer in W\n", + "I = math.sqrt(Q/R);\t\t\t#Maximum safe current limit in A\n", + "rc = ((kplastic*100)/h);\t\t\t#Critical radius in cm\n", + "\n", + "# Results\n", + "print 'The maximum safe current limit is %3.3f A \\n \\\n", + "As the critical radius of insulation is much greater,the current carrying capacity of the conductor can be raised upto %3.1f cm \\n \\\n", + "considerably in increasing the radius of plastic covering'%(I,rc)\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "The maximum safe current limit is 1.074 A \n", + " As the critical radius of insulation is much greater,the current carrying capacity of the conductor can be raised upto 6.2 cm \n", + " considerably in increasing the radius of plastic covering\n" + ] + } + ], + "prompt_number": 6 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 3.20 Page No : 83" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "L = 0.1;\t\t\t#Thickness of the wall in m\n", + "Q = (4*10**4);\t\t\t#Heat transfer rate in W/m**3\n", + "h = 50;\t\t\t#Convective heat transfer coefficient in W/m**2.K\n", + "T = 20;\t\t\t#Ambient air temperature in degree C\n", + "k = 15;\t\t\t#Thermal conductivity of the material in W/m.K\n", + "\n", + "# Calculations\n", + "Tw = (T+((Q*L)/(2*h)));\t\t\t#Surface temperature in degree C\n", + "Tmax = (Tw+((Q*L*L)/(8*k)));\t\t\t#Maximum temperature in the wall in degree C\n", + "\n", + "# Results\n", + "print 'Surface temperature is %i degree C \\nMaximum temperature in the wall is %3.3f degree C'%(Tw,Tmax)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Surface temperature is 60 degree C \n", + "Maximum temperature in the wall is 63.333 degree C\n" + ] + } + ], + "prompt_number": 7 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 3.21 Page No : 85" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math\n", + "\n", + "# Variables\n", + "Do = 0.006;\t\t\t#Outer diameter of hallow cylinder in m\n", + "Di = 0.004;\t\t\t#Inner diameter of hallow cylinder in m\n", + "I = 1000;\t\t\t#Current in A\n", + "T = 30;\t\t\t#Temperature of water in degree C\n", + "h = 35000;\t\t\t#Heat transfer coefficient in W/m**2.K\n", + "k = 18;\t\t\t#Thermal conductivity of the material in W/m.K\n", + "R = 0.1;\t\t\t#Electrical reisitivity of the material in ohm.mm**2/m\n", + "\n", + "# Calculations\n", + "ro = (Do/2);\t\t\t#Outer radius of hallow cylinder in m\n", + "ri = (Di/2);\t\t\t#Inner radius of hallow cylinder in m\n", + "V = ((3.14*(ro**2-ri**2)));\t\t\t#Vol. of wire in m**2\n", + "Rth = (R/(3.14*(ro**2-ri**2)*10**6));\t\t\t#Resistivity in ohm/mm**2\n", + "q = ((I*I*Rth)/V);\t\t\t#Heat transfer rate in W/m**3\n", + "To = T+(((q*ri*ri)/(4*k))*((((2*k)/(h*ri))-1)*((ro/ri)**2-1)+(2*(ro/ri)**2*math.log(ro/ri))));\t\t\t#Temperature at the outer surface in degree C\n", + "\n", + "# Results\n", + "print 'Temperature at the outer surface is %3.2f degree C'%(To)" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Temperature at the outer surface is 57.44 degree C\n" + ] + } + ], + "prompt_number": 31 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 3.22 Page No : 88" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "D = 0.025;\t\t\t#Diameter of annealed copper wire in m\n", + "I = 200;\t\t\t#Current in A\n", + "R = (0.4*10**-4);\t#Resistance in ohm/cm\n", + "T = [200,10];\t\t#Surface temperature and ambient temperature in degree C\n", + "k = 160;\t\t\t#Thermal conductivity in W/m.K\n", + "\n", + "# Calculations\n", + "r = (D/2);\t\t\t#Radius of annealed copper wire in m\n", + "Q = (I*I*R*100);\t#Heat transfer rate in W/m\n", + "V = (3.14*r*r);\t #Vol. of wire in m**2\n", + "q = (Q/V);\t\t\t#Heat loss in conductor in W/m**2\n", + "Tc = T[0]+((q*r*r)/(4*k));\t\t\t#Maximum temperature in the wire in degree C\n", + "h = ((r*q)/(2*(T[0]-T[1])));\t\t#Heat transfer coefficient in W/m**2.K\n", + "\n", + "# Results\n", + "print 'Maximum temperature in the wire is %3.2f degree C \\nHeat transfer coefficient is %3.2f W/m**2.K'%(Tc,h)" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Maximum temperature in the wire is 200.08 degree C \n", + "Heat transfer coefficient is 10.73 W/m**2.K\n" + ] + } + ], + "prompt_number": 8 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 3.23 Page No : 89" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math\n", + "\n", + "# Variables\n", + "p = 100.;\t\t\t#Resistivity of nichrome in \u00b5 ohm-cm \n", + "Q = 10000.;\t\t\t#Heat input of a heater in W\n", + "T = 1220.;\t\t\t#Surface temperature of nichrome in degree C\n", + "Ta = 20.;\t\t\t#Temperature of surrounding air in degree C\n", + "h = 1150.;\t\t\t#Outside surface coeffient in W/m**2.K\n", + "k = 17.;\t\t\t#Thermal conductivity of nichrome in W/m.K\n", + "L = 1.; \t\t\t#Length of heater in m\n", + "\n", + "# Calculations\n", + "d = (Q/((T-Ta)*3.14*h))*1000;\t#Diameter of nichrome wire in mm\n", + "A = (3.14*d*d)/4;\t\t\t #Area of the wire in m**2\n", + "R = ((p*10**-8*L)/A);\t\t\t#Resistance of the wire in ohm\n", + "I = math.sqrt(Q/R)/1000;\t\t#Rate of current flow in A\n", + "\n", + "# Results\n", + "print 'Diameter of nichrome wire is %3.4f mm \\n \\\n", + "Rate of current flow is %i A'%(d,I)" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Diameter of nichrome wire is 2.3078 mm \n", + " Rate of current flow is 204 A\n" + ] + } + ], + "prompt_number": 33 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 3.24 Page No : 93" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "Do = 0.025;\t\t\t#O.D of the rod in m\n", + "k = 20;\t\t\t#Thermal conductivity in W/m.K\n", + "Q = (2.5*10**6);\t\t\t#Rate of heat removal in W/m**2\n", + "\n", + "# Calculations\n", + "ro = (Do/2);\t\t\t#Outer radius of the rod in m\n", + "q = ((4*Q)/(ro));\t\t\t#Heat transfer rate in W/m**3\n", + "T = ((-3*q*ro**2)/(16*k));\t\t\t#Temperature drop from the centre line to the surface in degree C\n", + "\n", + "# Results\n", + "print 'Temperature drop from the centre line to the surface is %3.3f degree C'%(T)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Temperature drop from the centre line to the surface is -1171.875 degree C\n" + ] + } + ], + "prompt_number": 34 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 3.25 Page No : 95" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "Q = 300;\t\t\t#Heat produced by the oranges in W/m**2\n", + "s = 0.08;\t\t\t#Size of the orange in m\n", + "k = 0.15;\t\t\t#Thermal conductivity of the sphere in W/m.K\n", + "\n", + "# Calculations\n", + "q = (3*Q)/(s/2);\t\t\t#Heat flux in W/m**2\n", + "Tc = 10+((q*(s/2)**2)/(6*k));\t\t\t#Temperature at the centre of the sphere in degree C\n", + "\n", + "# Results\n", + "print 'Temperature at the centre of the orange is %i degree C'%(Tc)" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Temperature at the centre of the orange is 50 degree C\n" + ] + } + ], + "prompt_number": 35 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 3.26 Page No : 102" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math\n", + "\n", + "# Variables\n", + "To = 140;\t\t\t#Temperature at the junction in degree C\n", + "Ti = 15;\t\t\t#Temperature of air in the room in degree C\n", + "D = 0.003;\t\t\t#Diameter of the rod in m\n", + "h = 300;\t\t\t#Heat transfer coefficient in W/m**2.K\n", + "k = 150;\t\t\t#Thermal conductivity in W/m.K\n", + "\n", + "# Calculations\n", + "P = (3.14*D);\t\t\t#Perimeter of the rod in m\n", + "A = (3.14*D**2)/4;\t\t\t#Area of the rod in m**2\n", + "Q = math.sqrt(h*P*k*A)*(To-Ti);\t\t\t#Total heat dissipated by the rod in W\n", + "\n", + "# Results\n", + "print 'Total heat dissipated by the rod is %3.3f W'%(Q)" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Total heat dissipated by the rod is 6.841 W\n" + ] + } + ], + "prompt_number": 36 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 3.27 Page No : 103" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math\n", + "\n", + "# Variables\n", + "D = 0.025\t\t\t#Diameter of the rod in m\n", + "Ti = 22.;\t\t\t#Temperature of air in the room in degree C\n", + "x = 0.1;\t\t\t#Dismtance between the points in m\n", + "T = [110.,85.];\t\t#Temperature sat two points in degree C\n", + "h = 28.4;\t\t\t#Heat transfer coefficient in W/m**2.K\n", + "\n", + "# Calculations\n", + "m = -math.log((T[1]-Ti)/(T[0]-Ti))/x;\t\t\t#Calculation of m for obtaining k\n", + "P = (3.14*D);\t\t\t#Perimeter of the rod in m\n", + "A = (3.14*D**2)/4;\t\t\t#Area of the rod in m**2\n", + "k = ((h*P)/((m)**2*A));\t\t\t#Thermal conductivity of the rod material in W/m.K\n", + "\n", + "# Results\n", + "print 'Thermal conductivity of the rod material is %3.1f W/m.K'%(k)" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Thermal conductivity of the rod material is 406.8 W/m.K\n" + ] + } + ], + "prompt_number": 38 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 3.28 Page No : 103" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math\n", + "\n", + "# Variables\n", + "L = 0.06;\t\t\t#Length of the turbine blade in m\n", + "A = (4.65*10**-4);\t#Cross sectional area in m**2\n", + "P = 0.12;\t\t\t#Perimeter in m\n", + "k = 23.3;\t\t\t#Thermal conductivity of stainless steel in W/m.K\n", + "To = 500;\t\t\t#Temperature at the root in degree C\n", + "Ti = 870;\t\t\t#Temperature of the hot gas in degree C\n", + "h = 442;\t\t\t#Heat transfer coefficient in W/m**2.K\n", + "\n", + "# Calculations\n", + "m = math.sqrt((h*P)/(k*A));\t\t\t#Calculation of m for calculating heat transfer rate\n", + "X = (To-Ti)/math.cosh(m*L);\t\t\t#X for calculating tempetarure distribution\n", + "Q = math.sqrt(h*P*k*A)*(To-Ti)*math.tanh(m*L);\t\t\t#Heat transfer rate in W\n", + "\n", + "# Results\n", + "print 'Temperature distribution is given by :\\n T-Ti = %i cosh[%3.2f%3.2f-x)] cosh[%3.2f%3.2f)] \\n \\\n", + "Heat transfer rate is %3.1f W'%(To-Ti,m,L,m,L,Q)\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Temperature distribution is given by :\n", + " T-Ti = -370 cosh[69.970.06-x)] cosh[69.970.06)] \n", + " Heat transfer rate is -280.4 W\n" + ] + } + ], + "prompt_number": 15 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 3.29 Page No : 104" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math\n", + "\n", + "# Variables\n", + "W = 1;\t\t\t#Length of the cylinder in m\n", + "D = 0.05;\t\t\t#Diameter of the cylinder in m\n", + "Ta = 45;\t\t\t#Ambient temperature in degree C\n", + "n = 10;\t\t\t#Number of fins\n", + "k = 120;\t\t\t#Thermal conductivity of the fin material in W/m.K\n", + "t = 0.00076;\t\t\t#Thickness of fin in m\n", + "L = 0.0127;\t\t\t#Height of fin in m\n", + "h = 17;\t\t\t#Heat transfer coefficient in W/m**2.K\n", + "Ts = 150;\t\t\t#Surface temperature of cylinder in m\n", + "\n", + "# Calculations\n", + "P = (2*W);\t\t\t#Perimeter of cylinder in m\n", + "A = (W*t);\t\t\t#Surface area of cyinder in m**2\n", + "m = round(math.sqrt((h*P)/(k*A)),2);\t\t\t#Calculation of m for determining heat transfer rate\n", + "Qfin = (math.sqrt(h*P*k*A)*(Ts-Ta)*((math.tanh(m*L)+(h/(m*k)))/(1+((h/(m*k))*math.tanh(m*L)))));\t\t\t#Heat transfer through the fin in kW\n", + "Qb = h*((3.14*D)-(n*t))*W*(Ts-Ta);\t\t\t#Heat from unfinned (base) surface in W\n", + "Q = ((Qfin*10)+Qb);\t\t\t#Total heat transfer in W\n", + "Ti = ((Ts-Ta)/(math.cosh(m*L)+((h*math.sinh(m*L))/(m*k))));\t\t\t#Ti to calculate temperature at the end of the fin in degree C\n", + "T = (Ti+Ta);\t\t\t#Temperature at the end of the fin in degree C\n", + "\n", + "# Results\n", + "print 'Rate of heat transfer is %3.2f W \\nTemperature at the end of the fin is %3.2f degree C'%(Q,T )\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Rate of heat transfer is 723.99 W \n", + "Temperature at the end of the fin is 146.74 degree C\n" + ] + } + ], + "prompt_number": 12 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 3.31 Page No : 109" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math\n", + "\n", + "# Variables\n", + "t = 0.025;\t\t\t#Thickness of fin in m\n", + "L = 0.1;\t\t\t#Length of fin in m\n", + "k = 17.7;\t\t\t#Thermal conductivity of the fin material in W/m.K\n", + "p = 7850;\t\t\t#Density in kg/m**3\n", + "Tw = 600;\t\t\t#Temperature of the wall in degree C\n", + "Ta = 40;\t\t\t#Temperature of the air in degree C\n", + "h = 20;\t\t\t #Heat transfer coefficient in W/m**2.K\n", + "I0 = 2.1782;\t\t\t#Io value taken from table 3.2 on page no.108\n", + "I1 = 1.48871;\t\t\t#I1 value taken from table 3.2 on page no. 108\n", + "\n", + "# Calculations\n", + "B = math.sqrt((2*L*h)/(k*t));\t\t\t#Calculation of B for determining temperature distribution \n", + "\n", + "X = ((Tw-Ta)/2.1782);\t\t\t#Calculation of X for determining temperature distribution \n", + "Y = (2*B);\t\t\t#Calculation of Y for determining temperature distribution \n", + "Q = (math.sqrt(2*h*k*t)*(Tw-Ta)*((1.48871))/(2.1782));\n", + "m = ((p*t*L)/2);\t\t\t#Mass of the fin per meter of width in kg/m\n", + "q = (Q/m);\t\t\t#Rate of heat flow per unit mass in W/kg\n", + "\n", + "# Results\n", + "print 'Temperature distribution is T = %i+%3.1f(%3.4f\u221ax) \\n \\\n", + "Rate of heat flow per unit \\\n", + " mass of the fin is %3.2f W/kg'%(Ta,X,Y,q)\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Temperature distribution is T = 40+257.1(6.0132\u221ax) \n", + " Rate of heat flow per unit mass of the fin is 164.10 W/kg\n" + ] + } + ], + "prompt_number": 10 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 3.32 Page No : 116" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math\n", + "\n", + "# Variables\n", + "t = 0.002;\t\t\t#Thickness of fin in m\n", + "L = 0.015;\t\t\t#Length of fin in m\n", + "k1 = 210.;\t\t\t#Thermal conductivity of aluminium in W/m.K\n", + "h1 = 285.;\t\t\t#Heat transfer coefficient of aluminium in W/m**2.K\n", + "k2 = 40.;\t\t\t#Thermal conductivity of steel in W/m.K\n", + "h2 = 510.;\t\t\t#Heat transfer coefficient of steel in W/m**2.K\n", + "\n", + "# Calculations\n", + "Lc = (L+(t/2));\t\t\t#Corrected length of fin in m\n", + "mLc1 = Lc*math.sqrt((2*h1)/(k1*t));\t\t\t#Calculation of mLc for efficiency\n", + "n1 = math.tanh(mLc1)/mLc1;\t\t\t#Efficiency of fin when aluminium is used\n", + "mLc2 = Lc*math.sqrt((2*h2)/(k2*t));\t\t\t#Calculation of mLc for efficiency\n", + "n2 = math.tanh(mLc2)/mLc2;\t\t\t#Efficiency of fin when steel is used\n", + "\n", + "\n", + "# Results\n", + "print 'Efficiency of fin when aluminium is used is %3.4f \\n \\\n", + "Efficiency of fin when steel is used is %3.3f'%(n1,n2)\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Efficiency of fin when aluminium is used is 0.8983 \n", + " Efficiency of fin when steel is used is 0.524\n" + ] + } + ], + "prompt_number": 11 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 3.33 Page No : 117" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math\n", + "\n", + "# Variables\n", + "k = 200;\t\t\t#Thermal conductivity of aluminium in W/m.K\n", + "t = 0.001;\t\t\t#Thickness of fin in m\n", + "L = 0.015;\t\t\t#Width of fin in m\n", + "D = 0.025;\t\t\t#Diameter of the tube in m\n", + "Tb = 170;\t\t\t#Fin base temperature in degree C\n", + "Ta = 25;\t\t\t#Ambient fluid temperature in degree C\n", + "h = 130;\t\t\t#Heat transfer coefficient in W/m**2.K\n", + "\n", + "# Calculations\n", + "Lc = (L+(t/2));\t\t\t#Corrected length of fin in m\n", + "r1 = (D/2);\t\t\t#Radius of tube in m\n", + "r2c = (r1+Lc);\t\t\t#Corrected radius in m\n", + "Am = t*(r2c-r1);\t\t\t#Corrected area in m**2\n", + "x = Lc**(3/2)*math.sqrt(h/(k*Am));\t\t\t#x for calculating efficiency\n", + "n = 0.82;\t\t\t#From fig. 3.18 on page no. 112 efficiency is 0.82\n", + "qmax = (2*3.14*(r2c**2-r1**2)*h*(Tb-Ta));\t\t\t#Maximum heat transfer in W\n", + "qactual = (n*qmax);\t\t\t#Actual heat transfer in W\n", + "\n", + "# Results\n", + "print 'Heat loss per fin is %3.2f W'%(qactual)\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Heat loss per fin is 60.94 W\n" + ] + } + ], + "prompt_number": 51 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 3.34 Page No : 117" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math\n", + "\n", + "# Variables\n", + "k = 16;\t\t\t#Thermal conductivity of fin in W/m.K\n", + "L = 0.1;\t\t\t#Length of fin in m\n", + "D = 0.01;\t\t\t#Diameter of fin in m\n", + "h = 5000;\t\t\t#Heat transfer coefficient in W/m**2.K\n", + "\n", + "# Calculations\n", + "P = (3.14*D);\t\t\t#Perimeter of fin in m\n", + "A = (3.14*D**2)/4;\t\t\t#Area of fin in m**2\n", + "m = math.sqrt((h*P)/(k*A));\t\t\t#Calculation of m for determining heat transfer rate\n", + "n = math.tanh(m*L)/math.sqrt((h*A)/(k*P));\t\t\t#Calculation of n for checking whether installation of fin is desirable or not\n", + "x = (n-1)*100;\t\t\t#Conversion into percentage\n", + "\n", + "# Results\n", + "print 'This large fin only produces an increase of %i percent in heat dissipation, \\\n", + " so naturally this configuration is undesirable'%(x)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "This large fin only produces an increase of 13 percent in heat dissipation, so naturally this configuration is undesirable\n" + ] + } + ], + "prompt_number": 52 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 3.35 Page No : 119" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math\n", + "\n", + "# Variables\n", + "k = 55.8;\t\t\t#Thermal conductivity of steel in W/m.K\n", + "t = 0.0015;\t\t\t#Thickness of steel tube in m\n", + "L = 0.12;\t\t\t#Length of steel tube in m\n", + "h = 23.3;\t\t\t#Heat transfer coefficient in W/m**2.K\n", + "Tl = 84;\t\t\t#Temperature recorded by the thermometer in degree C\n", + "Tb = 40;\t\t\t#Temperature at the base of the well in degree C\n", + "\n", + "# Calculations\n", + "m = math.sqrt(h/(k*t));\t\t\t#Calculation of m for determining the temperature distribution\n", + "x = 1./math.cosh(m*L);\t\t\t#Calculation of x for determining the temperature distribution\n", + "Ti = ((Tl-(x*Tb))/(1-x));\t\t\t#Temperature distribution in degree C\n", + "T = (Ti-Tl);\t\t\t#Measurement error in degree C\n", + "\n", + "# Results\n", + "print 'Measurement error is %3.0f degree C'%(T)\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Measurement error is 16 degree C\n" + ] + } + ], + "prompt_number": 16 + } + ], + "metadata": {} + } + ] +}
\ No newline at end of file diff --git a/Fundamentals_Of_Engineering_Heat_And_Mass_Transfer/ch5.ipynb b/Fundamentals_Of_Engineering_Heat_And_Mass_Transfer/ch5.ipynb new file mode 100755 index 00000000..e575c46c --- /dev/null +++ b/Fundamentals_Of_Engineering_Heat_And_Mass_Transfer/ch5.ipynb @@ -0,0 +1,1137 @@ +{ + "metadata": { + "name": "", + "signature": "sha256:61a219887cda63633e57a8123bccc97a816d976e2f7d7f9c9b9bf006f781c953" + }, + "nbformat": 3, + "nbformat_minor": 0, + "worksheets": [ + { + "cells": [ + { + "cell_type": "heading", + "level": 1, + "metadata": {}, + "source": [ + "Chapter 5 : Transient Heat Conduction" + ] + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 5.1 Page No : 159" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math \n", + "\n", + "\n", + "# Variables\n", + "t = 0.5;\t\t\t#Thickness of slab in m\n", + "A = 5;\t\t\t#Area of slab in m**2\n", + "k = 1.2;\t\t\t#Thermal conductivity in W/m.K\n", + "a = 0.00177;\t\t\t#Thermal diffusivity in m**2/h\n", + "\n", + "# Calculations\n", + "x = 0;\n", + "y = -50+(24*x)+(60*x**2)-(60*x**3);\t\t\t#Temperature when x = 0\n", + "Qo = (-k*A*y);\t\t\t#Heat entering the slab in W \n", + "x = 0.5;\n", + "y = -50+(24*x)+(60*x**2)-(60*x**3);\t\t\t#Temperature when x = 0.5\n", + "QL = (-k*A*y);\t\t\t#Heat leaving the slab in W\n", + "R = (Qo-QL);\t\t\t#Rate of heat storage in W\n", + "x = 0;\n", + "z1 = 24+(120*x)-(180*x**2);\t\t\t#T' when x = 0\n", + "p1 = (a*z1);\t\t\t#Rate of temperature change at one side of slab in degree C/h\n", + "x = 0.5;\n", + "z2 = 24+(120*x)-(180*x**2);\t\t\t#T' when x = 0.5\n", + "p2 = (a*z2);\t\t\t#Rate of temperature change at one side of slab in degree C/h\n", + "\t\t\t#For the rate of heating or cooling to be maximum, T''' = 0\n", + "x = (120./360);\n", + "\n", + "# Results\n", + "print 'a)\\n \\\n", + "i)Heat entering the slab is %i W \\n \\\n", + "ii)Heat leaving the slab is %i W \\n\\n\\\n", + "b)Rate of heat storage is %i Wc \\n \\\n", + "i)Rate of temperature change at one side of slab is %3.4f degree C/h \\n \\\n", + "ii)Rate of temperature change at other side of slab is %3.4f degree C/h \\\n", + "\\n\\nd)For the rate of heating or cooling to be maximum x = %3.2f'%(Qo,QL,R,p1,p2,x)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "a)\n", + " i)Heat entering the slab is 300 W \n", + " ii)Heat leaving the slab is 183 W \n", + "\n", + "b)Rate of heat storage is 117 Wc \n", + " i)Rate of temperature change at one side of slab is 0.0425 degree C/h \n", + " ii)Rate of temperature change at other side of slab is 0.0690 degree C/h \n", + "\n", + "d)For the rate of heating or cooling to be maximum x = 0.33\n" + ] + } + ], + "prompt_number": 7 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 5.2 Page No : 164" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math\n", + "\n", + "# Variables\n", + "A = (0.4*0.4);\t\t\t#Area of copper slab in m**2\n", + "t = 0.005;\t\t\t#Thickness of copper slab in m\n", + "T = 250.;\t\t\t#Uniform teperature in degree c\n", + "Ts = 30.;\t\t\t#Surface temperature in degree C\n", + "Tsl = 90.;\t\t\t#Slab temperature in degree C\n", + "p = 9000.;\t\t\t#Density in kg/m**3\n", + "c = 380.;\t\t\t#Specific heat in J/kg.K\n", + "k = 370.;\t\t\t#Thermal conductivity in W/m.K\n", + "h = 90.;\t\t\t#Heat transfer coefficient in W/m**2.K\n", + "\n", + "# Calculations\n", + "A1 = (2*A);\t\t\t#Area of two sides in m**2\n", + "V = (A*t);\t\t\t#Volume of the slab in m**3\n", + "Lc = (V/A1);\t\t\t#Corrected length in m\n", + "Bi = ((h*Lc)/k);\t\t\t#Biot number\n", + "t = -math.log((Tsl-Ts)/(T-Ts))/((h*A1)/(p*c*V));\t\t\t#Time at which slab temperature becomes 90 degree C in s\n", + "y = (h*A1)/(p*c*V);\n", + "\n", + "# Results\n", + "print 'Time at which slab temperature becomes 90 degree C is %3.2f s'%(t)\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Time at which slab temperature becomes 90 degree C is 123.43 s\n" + ] + } + ], + "prompt_number": 3 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 5.3 Page No : 164" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math\n", + "\n", + "# Variables\n", + "D = 0.01;\t\t\t#Outer diameter of the rod in m\n", + "T = 320.;\t\t\t#Original temperature in degree C\n", + "Tl = 120.;\t\t\t#Temperature of liquid in degree C\n", + "h = 100.;\t\t\t#Heat transfer coefficient in W/m**2.K\n", + "Tf = 200.;\t\t\t#Final temperature of rod in degree C\n", + "k = 40.;\t\t\t#Thermal conductivity in W/m.K\n", + "c = 460.;\t\t\t#Specific heat in J/kg.K\n", + "p = 7800.;\t\t\t#Density in kg/m**3\n", + "\n", + "# Calculations\n", + "V = (3.14*D**2*1)/4;\t\t#Volume of rod in m**3 taking 1m length\n", + "A = (3.14*D*1);\t\t \t#Surface area of rod in m**2 taking 1m length\n", + "Lc = (D/4);\t\t\t #Corrected length in m\n", + "Bi = ((h*Lc)/k);\t\t\t#Biot number\n", + "t = -math.log((Tf-Tl)/(T-Tl))/((h*4)/(p*c*D));\t\t\t#Time at which rod temperature becomes 200 degree C in s\n", + "\n", + "# Results\n", + "print 'Time at which rod temperature becomes 200 degree C is %3.2f s'%(t)\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Time at which rod temperature becomes 200 degree C is 82.19 s\n" + ] + } + ], + "prompt_number": 4 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 5.4 Page No : 165" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math\n", + "\n", + "# Variables\n", + "w = 5.5;\t\t\t#Weight of the sphere in kg\n", + "Ti = 290.;\t\t\t#Initial temperature in degree C\n", + "Tl = 15.;\t\t\t#Temperature of liquid in degree C\n", + "h = 58.;\t\t\t#Heat transfer coefficient in W/m**2.K\n", + "Tf = 95.;\t\t\t#Final temperature in degree C\n", + "k = 205.;\t\t\t#Thermal conductivity in W/m.K\n", + "c = 900.;\t\t\t#Specific heat in J/kg.K\n", + "p = 2700.;\t\t\t#Density in kg/m**3\n", + "\n", + "# Calculations\n", + "V = (w/p);\t\t\t#Volume of the sphere in m**3\n", + "R = ((3*V)/(4*3.14))**(1./3);\t\t\t#Radius of sphere in m\n", + "Lc = (R/3.);\t\t\t#Corrected length in m\n", + "t = -math.log((Tf-Tl)/(Ti-Tl))/((h*3)/(p*c*R));\t\t\t#Time at which rod temperature becomes 95 degree C in s\n", + "\n", + "# Results\n", + "print 'Time at which rod temperature becomes 95 degree C is %3.0f s'%(t)\n", + "\n", + "\n", + "# note : answer is slightly different because of rouding off error." + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Time at which rod temperature becomes 95 degree C is 1356 s\n" + ] + } + ], + "prompt_number": 3 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 5.5 Page No : 166" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math\n", + "\n", + "# Variables\n", + "Ti = 100.;\t\t\t#Temperature of air in degree C\n", + "t = 0.03;\t\t\t#Thickness of slab in m\n", + "To = 210.;\t\t\t#Initial temperature of the plate in degree C\n", + "t = 300.;\t\t\t#Time for attaining temperature in s\n", + "T = 170.;\t\t\t#Temperature decreased in degree C\n", + "c = 380.;\t\t\t#Specific heat in J/kg.K\n", + "p = 9000.;\t\t\t#Density in kg/m**3\n", + "\n", + "# Calculations\n", + "Lc = (t/2);\t\t\t#Corrected length in m\n", + "h = -math.log((T-Ti)/(To-Ti))/((t*10**4)/(p*c*Lc));\t\t\t#Heat transfer coefficient in W/m**2.K\n", + "\n", + "# Results\n", + "print 'Heat transfer coefficient is %3.2f W/m**2.K'%(h)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Heat transfer coefficient is 77.29 W/m**2.K\n" + ] + } + ], + "prompt_number": 7 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 5.6 Page No : 167" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math\n", + "\n", + "# Variables\n", + "D = 0.00071;\t\t\t#Diameter of thermocouple in m\n", + "h = 600.;\t\t\t#Heat transfer coefficient in W/m**2.K\n", + "c = 420.;\t\t\t#Specific heat in J/kg.K\n", + "p = 8600.;\t\t\t#Density in kg/m**3\n", + "\n", + "# Calculations\n", + "t = (p*c*D)/(4*h);\t\t\t#Time period in s\n", + "T = math.exp(-1);\t\t\t#Temperture distribution ratio\n", + "t1 = (4*t);\t\t\t#Total time in s\n", + "\n", + "# Results\n", + "print 'At the end of time period t* = %3.3f s the temperature difference \\\n", + " between the body and the source would be %3.3f of the initial temperature differnce.\\n\\\n", + " To get a true reading of gas temperature, it should be recorded after 4t* = %i seconds after\\\n", + " the thermocouple has been \\nintroduced into the stream'%(t,T,t1)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "At the end of time period t* = 1.069 s the temperature difference between the body and the source would be 0.368 of the initial temperature differnce.\n", + " To get a true reading of gas temperature, it should be recorded after 4t* = 4 seconds after the thermocouple has been \n", + "introduced into the stream\n" + ] + } + ], + "prompt_number": 14 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 5.8 Page No : 177" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math\n", + "\n", + "# Variables\n", + "x = 0.2;\t\t\t#Distance of plane from the wall in m\n", + "t = 10;\t\t\t#Time for heat flow in h\n", + "T = [25,800];\t\t\t#Initial and final tempertaure in degree C\n", + "k = 0.8;\t\t\t#Thermal conductivity in W/m.K\n", + "a = 0.003;\t\t\t#Thermal diffusivity in m**2/h\n", + "\n", + "# Calculations\n", + "X = (x*(2*math.sqrt(a*t)));\t\t\t#Calculation of X for erf function\n", + "Y = 0.585 #erf(X) from table 5.1\n", + "Ti = T[1]-((T[1]-T[0]))*Y;\t\t\t#Temperarture of the plane in degree C\n", + "Qi = ((-k*(T[0]-T[1])*math.exp(-x**2/(4*a*t)))/(math.sqrt(3.14*a*t)));\t\t\t#Instanteneous heat flow rate per unit area in W/m**2\n", + "Q = ((2*k*(T[1]-T[0])*3600)/(math.sqrt((3.14*a)/t)))/10**8;\t\t\t #Total heat energy taken up by the wall in 10 hours in J/m**2\n", + "print \n", + "# Results\n", + "print 'Temperarture of the plane is %3.2f degree C\\nInstanteneous heat flow rate per \\\n", + " unit area is %i W/m**2 \\nTotal heat energy taken up by the wall in 10 hours is %3.3f*10**8 J/m**2'%(Ti,Qi,Q)" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "\n", + "Temperarture of the plane is 346.62 degree C\n", + "Instanteneous heat flow rate per unit area is 1447 W/m**2 \n", + "Total heat energy taken up by the wall in 10 hours is 1.454*10**8 J/m**2\n" + ] + } + ], + "prompt_number": 28 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 5.9 Page No : 177" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "Tc = 55;\t\t\t#Tempertaure of the concrete in degree C\n", + "Ts = 35;\t\t\t#Temperature lowered in degree C\n", + "Tf = 45;\t\t\t#Final temperature in degree C\n", + "x = 0.05;\t\t\t#Depth of the slab in m\n", + "k = 1.279;\t\t\t#Thermal conductivity in W/m.K\n", + "a = 0.00177;\t\t\t#Thermal diffusivity in m**2/h\n", + "\n", + "# Calculations\n", + "T = (Tf-Ts)/(Tc-Ts);\t\t\t#Temperature distribution\n", + "X = 0.485;\t\t\t#Taking 0.5 = erf(0.482) from table 5.1 on page no. 175\n", + "t = (x**2)/(4*X**2*a);\t\t\t#Time taken to cool the concrete to 45 degree C in h\n", + "\n", + "# Results\n", + "print 'Time taken to cool the concrete to 45 degree C is %3.2f h'%(t)\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Time taken to cool the concrete to 45 degree C is 1.50 h\n" + ] + } + ], + "prompt_number": 11 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 5.10 Page No : 178" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math\n", + "\n", + "# Variables\n", + "q = (0.3*10**6);\t\t\t#Heat flux in W/m**2\n", + "t = (10./60);\t\t\t#Time taken for heat transfer in s\n", + "Ti = 30.;\t\t\t#Initial temperature of the slab in degree C\n", + "x = 0.2;\t\t\t#Distance of the plane from the surface in m\n", + "k = 386.;\t\t\t#Thermal conductivity in W/m.K\n", + "a = 0.404;\t\t\t#Thermal diffusivity in m**2/h\n", + "\n", + "# Calculations\n", + "Ts = ((q*math.sqrt(3.14*a*t))/k)+Ti;\t\t\t#Surface temperature in degree C\n", + "X = (x/(2*math.sqrt(a*t)));\t\t\t#X for calculating erf function\n", + "Y = 0.4134;\t\t\t#Taking ref(0.385) = 0.4134 from table 5.1 on page no. 175\n", + "T = Ts-(Y*(Ts-Ti));\t\t\t#Tempertaure at a distance of 20 cm from the surface after 10 min in degree C\n", + "\n", + "# Results\n", + "print 'Tempertaure at a distance of 20 cm from the surface after 10 min is %3.2f degree C'%(T)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Tempertaure at a distance of 20 cm from the surface after 10 min is 239.63 degree C\n" + ] + } + ], + "prompt_number": 12 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 5.11 Page No : 178" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math\n", + "\n", + "# Variables\n", + "a = 0.405;\t\t\t#Thermal diffusivity in m**2/h\n", + "Ti = 100;\t\t\t#Initial temperture in degree C\n", + "Tf = 0;\t\t\t#Final tempertaure in degree C\n", + "Tg = (4*100);\t#Temperature gradient in degree C/m\n", + "t1 = 1;\t\t\t#Time taken in m\n", + "\n", + "# Calculations\n", + "t = (Ti-Tf)**2/(Tg**2*3.14*a);\t\t\t#Time required for the temperature gradient at the surface to reach 4 degree/cm in h\n", + "x = math.sqrt(2*a*(t1/60.));\t\t\t#The depth at which the rate of cooling is maximum after 1 minute in m\n", + "\n", + "# Results\n", + "print 'Time required for the temperature gradient at the surface to reach 4 degree/cm is %3.3f h \\\n", + "\\nThe depth at which the rate of cooling is maximum after 1 minute is %3.4f m'%(t,x)\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Time required for the temperature gradient at the surface to reach 4 degree/cm is 0.049 h \n", + "The depth at which the rate of cooling is maximum after 1 minute is 0.1162 m\n" + ] + } + ], + "prompt_number": 15 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 5.12 Page No : 185" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "x = 0.1;\t\t\t#Thickness of the slab in m\n", + "Ti = 500;\t\t\t#Initial temperature in degree C\n", + "Tl = 100;\t\t\t#Liquid temperature in degree C\n", + "h = 1200;\t\t\t#Heat transfer coefficient in W/m**2.K\n", + "t = (1*60);\t\t\t#Time for immersion in s\n", + "k = 215;\t\t\t#Thermal conductivity in W/m.K\n", + "a = (8.4*10**-5);\t\t\t#Thermal diffusivity in m**2/h\n", + "c = 900;\t\t\t#Specific heat in J/kg/K\n", + "p = 2700;\t\t\t#Density in kg/m**3\n", + "\n", + "# Calculations\n", + "X = (a*t)/(x/2)**2;\t\t\t#Calculation for input in Heisler charts\n", + "B = (k/(h*(x/2)));\t\t\t#Calculation for input in Heisler charts\n", + "T1 = 0.68;\t\t\t#T value taken from Fig. 5.7 on page no. 183\n", + "Tc1 = (T1*(Ti-Tl));\t\t\t#Temperature in degree C\n", + "To = Tc1+Tl;\t\t\t#Temperature in degree C\n", + "T2 = 0.880;\t\t\t#From Fig 5.8 on page no. 184 at x/L = 1.0 and for k/hL = 3.583, tempertaure in degree C\n", + "Tc2 = (T2*(To-Tl))+Tl;\t\t\t#Temperature in degree C \n", + "Y = (h**2*a*t)/(k**2);\t\t\t#Y to calculate the energy losses\n", + "Bi = (h*(x/2))/k;\t\t\t#Biot number\n", + "U = 0.32;\t\t\t#U/Uo value from Fig. 5.9 on page no.185 \n", + "Uo = (p*c*x*(Ti-Tl));\t\t\t#For unit area in J/m**2\n", + "U1 = (U*Uo)/(10**6);\t\t\t#Heat removed per unit surface area in MJ/m**2\n", + "\n", + "# Results\n", + "print 'Temperature at the centreline and the surface 1 minute after the immersion is %3.2f degree C \\n \\\n", + "Heat removed per unit surface area is %3.1f*10**6 J/m**2'%(Tc2,U1)" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Temperature at the centreline and the surface 1 minute after the immersion is 339.36 degree C \n", + " Heat removed per unit surface area is 31.1*10**6 J/m**2\n" + ] + } + ], + "prompt_number": 16 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 5.13 Page No : 186" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "D = 0.12;\t\t\t#Diameter of cylinder in m\n", + "Ti = 20;\t\t\t#Initial temperature in degree C\n", + "Tf = 820;\t\t\t#Temperature of furnace in degree C\n", + "h = 140;\t\t\t#Heat transfer coefficient in W/m**2.K\n", + "Ta = 800;\t\t\t#Axis temperature in degree C\n", + "r = 0.054;\t\t\t#Radius in m\n", + "k = 21;\t\t\t#Thermal conductivity in W/m.K\n", + "a = (6.11*10**-6);\t\t\t#Thermal diffusivity in m**2/h\n", + "\n", + "# Calculations\n", + "Bi = (h*(D/2))/(2*k);\t\t\t#Biot number\n", + "T = (Ta-Tf)/(Ti-Tf);\t\t\t#Temperature distribution\n", + "Fo = 5.2;\t\t\t#Umath.sing Fig.5.10, on page no.187 for 1./(2Bi) = 2.5 \n", + "t = (Fo*(D/2)**2)/a;\t\t\t#Time required for the axis temperature to reach 800 degree C in s\n", + "r1 = (r/(D/2));\t\t\t#Ratio at a radius of 5.4 cm\n", + "X = 0.85;\t\t\t#From Fig.5.11 on page no. 188 the temperature at r = 5.4 i sgiven by X\n", + "T1 = X*(Ta-Tf)+Tf;\t\t\t#Temperature at a radius of 5.4 cm at that tim ein degree C\n", + "\n", + "# Results\n", + "print 'Time required for the axis temperature to reach 800 degree C is %3.0f s \\n \\\n", + "Temperature at a radius of 5.4 cm at that time is %i degree C'%(t,T1)\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Time required for the axis temperature to reach 800 degree C is 3064 s \n", + " Temperature at a radius of 5.4 cm at that time is 803 degree C\n" + ] + } + ], + "prompt_number": 17 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 5.14 Page No : 189" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math\n", + "import math\n", + "# Variables\n", + "r = 0.01;\t\t\t#Radius of the mettalic sphere in m\n", + "Ti = 400.;\t\t\t#Initial temperature in degree C\n", + "h1 = 10.;\t\t\t#Heat transfer coefficient in W/m**2.K\n", + "Ta = 20.;\t\t\t#Temperature of air in degree C\n", + "Tc = 335.;\t\t\t#Central temperature in degree C\n", + "Tw = 20.;\t\t\t#Temperature of water bath in degree C\n", + "h2 = 6000.;\t\t\t#Heat transfer coefficient in W/m**2.K\n", + "Tf = 50.;\t\t\t#Final temperature of the sphere in degree C\n", + "k = 20.;\t\t\t#Thermal conductivity in W/m.K\n", + "a = (6.66*10**-6);\t\t\t#Thermal diffusivity in m**2/h\n", + "c = 1000.;\t\t\t#Specific heat in J/kg/K\n", + "p = 3000.;\t\t\t#Density in kg/m**3\n", + "\n", + "# Calculations\n", + "Bi1 = (h1*r)/(3*k);\t\t\t#Biot number\n", + "t = ((p*r*c)/(3*h1)*math.log((Ti-Ta)/(Tc-Ta)))\t\t\t#Time required for cooling in air in s\n", + "Bi2 = (h2*r)/(3*k);\t\t\t#Biot number\n", + "X = 1./(3*Bi2);\t\t\t#X value for lumped capacity method\n", + "T = (Tf-Ta)/(Tc-Ta);\t\t\t#Temperature distribution\n", + "Fo = 0.5;\t\t\t#Umath.sing Fig.5.13, on page no.190\n", + "t1 = (Fo*r**2)/a;\t\t\t#Time required for cooling in water in s\n", + "Z = 0.33;\t\t\t#Umath.sing Fig.5.14, on page no.191\n", + "Tr = Z*(Tf-Ta)+Ta;\t\t\t#Surface temperature at the end of cooling in degree C\n", + "\n", + "\n", + "# Results\n", + "print 'Time required for cooling in air is %3.0f s \\n \\\n", + "Time required for cooling in water is %3.1f s \\n \\\n", + "Surface temperature at the end of cooling is %3.0f degree C'%(t,t1,Tr)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Time required for cooling in air is 188 s \n", + " Time required for cooling in water is 7.5 s \n", + " Surface temperature at the end of cooling is 30 degree C\n" + ] + } + ], + "prompt_number": 9 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 5.15 Page No : 192" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math\n", + "# Variables\n", + "Ti = 250.;\t\t\t#Temperature of aluminium slab in degree C\n", + "Tc = 50.;\t\t\t#Convective environment temperature in degree C\n", + "h = 500.;\t\t\t#Heat transfer coefficient in W/m**2.K\n", + "x = 0.05;\t\t\t#Depth of the plane in m\n", + "t = (1.*3600);\t\t\t#Time in s\n", + "k = 215.;\t\t\t#Thermal conductivity in W/m.K\n", + "a = (8.4*10**-5);\t\t\t#Thermal diffusivity in m**2/h\n", + "\n", + "# Calculations\n", + "X = (h*math.sqrt(a*t))/k;\t\t\t#X for calculating Temperature\n", + "Y = (x/(2*math.sqrt(a*t)));\t\t\t#Y for calculating Temperature\n", + "Z = 0.62;\t\t\t#From Fig. 5.16 on page no.193\n", + "T = (Z*(Tc-Ti)+Ti);\t\t\t#Temperature at a depth of 5 cm after 1 hour in degree C\n", + "\n", + "# Results\n", + "print 'Temperature at a depth of 5 cm after 1 hour is %3.0f degree C'%(T)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Temperature at a depth of 5 cm after 1 hour is 126 degree C\n" + ] + } + ], + "prompt_number": 19 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 5.16 Page No : 196" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "D = 0.08;\t\t\t#Diameter of the cylinder in m\n", + "L = 0.16;\t\t\t#Length of the cylinder in m\n", + "Ti = 800;\t\t\t#Initial tempertaure in degree C\n", + "Tm = 30;\t\t\t#Temperature of the medium in degree C\n", + "h = 120;\t\t\t#Heat transfer coefficient in W/m**2.K\n", + "t = (30*60);\t\t\t#Time for cooling in s\n", + "k = 23.5;\t\t\t#Thermal conductivity in W/m.K\n", + "a = 0.022;\t\t\t#Thermal diffusivity in m**2/h\n", + "\n", + "# Calculations\n", + "Bi2 = (h*(D/2))/k;\t\t\t#2 times the Biot number\n", + "X = (a*t)/(D/2)**2;\t\t\t#X for calculating C(R)\n", + "CR = 0.068;\t\t\t#From Fig.5.10 on page no.187\n", + "Bi1 = (k/(h*L));\t\t\t#Biot number\n", + "Y = (a*t)/L**2;\t\t\t#Y for calculating P(X)\n", + "PX = 0.54;\t\t\t#From Fig.5.7 on page no.183\n", + "T = CR*PX;\t\t\t#Temperature at the centre of the cylinder in degree C\n", + "T30 = T*(Ti-Tm)+Tm;\t\t\t#Temperature at the centre of cylinder 30 minutes after cooling is initiated in degree C\n", + "\n", + "# Results\n", + "print 'Temperature at the centre of cylinder 30 minutes after cooling is initiated is %3.2f degree C'%(T30)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Temperature at the centre of cylinder 30 minutes after cooling is initiated is 58.27 degree C\n" + ] + } + ], + "prompt_number": 20 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 5.17 Page No : 197" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math \n", + "from numpy import *\n", + "\n", + "\n", + "# Variables\n", + "L = array([0.5,0.4,0.2]);\t\t\t#Lengths of sides of a recmath.tangular steel billet in m\n", + "Ti = 30;\t\t\t#Initial temperature in degree C\n", + "Tf = 1000;\t\t\t#Final temperature in degree C\n", + "t = (90*60);\t\t\t#Time for heating in s\n", + "h = 185;\t\t\t#Heat transfer coefficient in W/m**2.K\n", + "k = 37;\t\t\t#Thermal conductivity in W/m.K\n", + "a = 0.025;\t\t\t#Thermal diffusivity in m**2/h\n", + "\n", + "# Calculations\n", + "L1 = L/2;\t\t\t#L values of the parallelepiped in m\n", + "Bi1 = (h*L[0])/k;\t\t\t#Biot number\n", + "X1 = (a*t)/L[0]**2;\t\t\t#X1 for calculating P(X1)\n", + "PX1 = 0.68;\t\t\t#P(X1) value from From Fig.5.7 on page no.183\n", + "Bi2 = (h*L[1])/k;\t\t\t#Biot number\n", + "X1 = (a*t)/L[1]**2;\t\t\t#X1 for calculating P(X2)\n", + "PX2 = 0.57;\t\t\t#P(X2) value from From Fig.5.7 on page no.183\n", + "Bi3 = (h*L[2])/k;\t\t\t#Biot number\n", + "Y = (1./Bi3);\t\t\t#Inverse of Biot number\n", + "X1 = (a*t)/L[2]**2;\t\t\t#X1 for calculating P(X3)\n", + "PX3 = 0.22;\t\t\t#P(X3) value from From Fig.5.7 on page no.183\n", + "T = PX1*PX2*PX3;\t\t\t#Temperature at the centre of billet in degree C\n", + "T1 = T*(Ti-Tf)+Tf;\t\t\t#Temperature at the centre of cylinder 90 minutes after heating is initiated in degree C\n", + "\n", + "# Results\n", + "print 'Temperature at the centre of cylinder 90 minutes after heating is initiated is %3.2f degree C'%(T1)\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Temperature at the centre of cylinder 90 minutes after heating is initiated is 917.29 degree C\n" + ] + } + ], + "prompt_number": 22 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 5.18 Page No : 202" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "Ti = 30;\t\t\t#Initial temperature of the slab in degree C\n", + "q = (2*10**5);\t\t\t#Constant heat flux in W/m**2\n", + "k = 400;\t\t\t#Thermal conductivity in W/m.K\n", + "a = (117*10**-6);\t\t\t#Thermal diffusivity in m**2/h\n", + "n = 0.075;\t\t\t#Nodal spacing in m\n", + "x = 0.15;\t\t\t#Depth in m\n", + "t = (4*60);\t\t\t#Time elapsed in s\n", + "\n", + "#CALCULATION\n", + "R = (x**2/(a*t));\t\t\t#R value for t1\n", + "t1 = (n**2/(R*a));\t\t\t#Value of t1 in s\n", + "To = 121.9;\t\t\t#The surface temperature after 4 min in degree C from the table on page no. 203\n", + "T2 = 64;\t\t\t#Temperature at 0.15 m from the surface after 4 minutes in degree C from the table on page no. 203\n", + "\n", + "# Results\n", + "print 'The surface temperature after 4 min is %3.1f degree C \\n \\\n", + "Temperature at 0.15 m from the surface after 4 minutes is %i degree C'%(To,T2)\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "The surface temperature after 4 min is 121.9 degree C \n", + " Temperature at 0.15 m from the surface after 4 minutes is 64 degree C\n" + ] + } + ], + "prompt_number": 23 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 5.19 Page No : 205" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "t = 0.6;\t\t\t#Thickness of the wall in m\n", + "x = 0.1;\t\t\t#x value taken from Fig.Ex. 5.19 on page no. 205\n", + "Ti = 20;\t\t\t#Initial temperature in degree C\n", + "T = [150,300];\t\t\t#Temperatures of the sides of the wall in degree C\n", + "Tf = 150;\t\t\t#Final temperature of the wall in degree C\n", + "a = (1.66*10**-3);\t\t\t#Thermal diffusivity in m**2/h\n", + "\n", + "# Calculations\n", + "t = (x**2/(2*a));\t\t\t#Length of one time increment in h\n", + "t1 = (9*t);\t \t\t#Elapsed time in h\n", + "\n", + "# Results\n", + "print 'Elasped time before the centre of the wall attains a temperature of 150 degree C is %3.0f h'%(t1)\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Elasped time before the centre of the wall attains a temperature of 150 degree C is 27 h\n" + ] + } + ], + "prompt_number": 24 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 5.20 Page No : 206" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "k = 0.175;\t\t\t#Thermal conductivity in W/m.K\n", + "a = (0.833*10**-7);\t\t\t#Thermal diffusivity in m**2/h\n", + "Th = 144;\t\t\t#Heated temeparture in degree C\n", + "Tc = 15;\t\t\t#Cooled temperature in degree C\n", + "x = 0.02;\t\t\t#Thickness of the plate in m\n", + "h = 65;\t\t\t#Heat transfer coefficient in W/m**2.K\n", + "t = (4*60);\t\t\t#Tiem elapsed in s\n", + "\n", + "# Calculations\n", + "s = 0.002;\t\t\t#Space increment in m from FIg. Ex. 5.20 on page no. 207\n", + "t1 = (s**2/(2*a));\t\t\t#Time increment for the space increment in s\n", + "x1 = (k/h);\t\t\t#Convective film thickness in mm\n", + "Tn = 114;\t\t\t#Temperature at the centre in degree C from Fig. Ex.5.20 on page no. 207\n", + "Ts = 50;\t\t\t#Surface temperature in degree C from Fig. Ex.5.20 on page no. 207\n", + "\n", + "# Results\n", + "print 'Temperature at the centre is %i degree C \\n \\\n", + "Surface temperature is %i degree C'%(Tn,Ts)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Temperature at the centre is 114 degree C \n", + " Surface temperature is 50 degree C\n" + ] + } + ], + "prompt_number": 25 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 5.21 Page No : 213" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math\n", + "# Variables\n", + "t = 24;\t\t\t#Time period in h\n", + "T = [-10,10];\t\t\t#Range of temperatures in degree C\n", + "x = 0.1;\t\t\t#Depth in m\n", + "c = 1970;\t\t\t#Specific heat in J/kg/K\n", + "p = 1000;\t\t\t#Density in kg/m**3\n", + "k = 0.349;\t\t\t#Thermal conductivity in W/m.K\n", + "ta = 5;\t\t\t#Time in h\n", + "\n", + "# Calculations\n", + "w = (2*3.14)/t;\t\t\t#Angular velocity in rad/h\n", + "Tm = (T[0]+T[1])/2;\t\t\t#Mean teperature in degree C\n", + "Tmax = T[1]-Tm;\t\t\t#Maximum temperature in degree C\n", + "a = ((k*3600)/(p*c));\t\t\t#Thermal diffusivity in m**2/h\n", + "Txmax = Tmax*exp(-math.sqrt(w/(2*a))*x);\t\t\t#Amplitude of temperature variation in degree C\n", + "t1 = math.sqrt(1./(2*a*w))*x;\t\t\t#Time lag of temperature wave at a depth of 0.1 m in h\n", + "t2 = (3.14/w);\t\t\t#Time for surface temperature is minimum in h\n", + "t3 = t2+ta;\t\t\t#Time in h\n", + "Tx = Tmax*exp(-math.sqrt(w/(2*a))*x)*math.cos((w*t3)-(x*x*math.sqrt(w/(2*a))));\t\t\t#Temperature at 0.1m 5 hours after the surface temperature reaches the minimum in degree C\n", + "\n", + "# Results\n", + "print 'Amplitude of temperature variation at a depth of 0.1m is %3.2f degree C \\n \\\n", + "Time lag of temperature wave at a depth of 0.1 m is %3.2f h \\n \\\n", + "Temperature at 0.1m 5 hours after the surface temperature reaches the minimum is %3.3f degree C'%(Txmax,t1,Tx)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Amplitude of temperature variation at a depth of 0.1m is 2.39 degree C \n", + " Time lag of temperature wave at a depth of 0.1 m is 5.47 h \n", + " Temperature at 0.1m 5 hours after the surface temperature reaches the minimum is -0.946 degree C\n" + ] + } + ], + "prompt_number": 27 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 5.22 Page No : 214" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math\n", + "\n", + "# Variables\n", + "T = [800.,200.];\t\t\t#Limits in which temperature varies in degree C\n", + "t = 12.;\t\t\t#Cycle time in h\n", + "x = 0.1;\t\t\t#Depth of penetration in m\n", + "k = 1.8;\t\t\t#Thermal conductivity in W/m.K\n", + "a = 0.02;\t\t\t#Thermal diffusivity in m**2/h\n", + "\n", + "# Calculations\n", + "w = (2*3.14)/t;\t\t\t#Angular velocity in rad/h\n", + "t1 = math.sqrt(1./(2*a*w))*x;\t\t\t#Time lag in h\n", + "Tmax = (T[0]-T[1])/2;\t\t\t#Range of maximum temperature in degree C\n", + "q = ((2*k*Tmax)/math.sqrt(math.pi/6*a))*(3600./1000);\t\t\t#Heat flow through the surface in kJ/m**2\n", + "\n", + "# Results\n", + "print 'i)Time lag of the temperature wave at a depth of 10 cm from the inner surface is %3.2f h \\n \\\n", + "ii)The flow through a surface located at a distance of 10 cm from the surface during the first\\\n", + " six hours interval while the temperature is above the mean value is %i kJ/m**2'%(t1,q) " + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "i)Time lag of the temperature wave at a depth of 10 cm from the inner surface is 0.69 h \n", + " ii)The flow through a surface located at a distance of 10 cm from the surface during the first six hours interval while the temperature is above the mean value is 37993 kJ/m**2\n" + ] + } + ], + "prompt_number": 12 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 5.23 Page No : 215" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "N = 2000;\t\t\t#Speed of the engine\n", + "a = 0.06;\t\t\t#Thermal diffusivity in m**2/h\n", + "\n", + "# Calculations\n", + "t = 1./(60*N);\t\t\t#Period of on oscillation in h\n", + "x = (1.6*math.sqrt(3.14*a*t))*1000;\t\t\t#Depth of penetration in mm\n", + "\n", + "# Results\n", + "print 'Depth of penetration of the temperature oscillation into the cylinder wall of a \\\n", + "single acting cylinder two stroke IC engine is%3.0f mm'%(x)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Depth of penetration of the temperature oscillation into the cylinder wall of a single acting cylinder two stroke IC engine is 2 mm\n" + ] + } + ], + "prompt_number": 29 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 5.24 Page No : 218" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math\n", + "# Variables\n", + "Tc = 55;\t\t\t#Tempaerature of concrete hyway in degree C\n", + "Tl = 35;\t\t\t#Temperature lowered in degree C\n", + "Tf = 45;\t\t\t#Final temperature in degree C\n", + "x = 0.05;\t\t\t#Depth in m\n", + "k = 1.279;\t\t\t#Thermal conductivity in W/m.K\n", + "a = (1.77*10**-3);\t\t\t#Thermal diffusivity in m**2/h\n", + "\n", + "# Calculations\n", + "t = 1.4;\t\t\t#Time taken from page no. 219 in h\n", + "q = 2*(k*(Tl-Tf))/(math.sqrt(3*a*t));\t\t\t#Instantaneous heat removal rate in W/m**2\n", + "\n", + "# Results\n", + "print 'Instantaneous heat removal rate is %3.1f W/m**2'%(q)" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Instantaneous heat removal rate is -296.7 W/m**2\n" + ] + } + ], + "prompt_number": 30 + } + ], + "metadata": {} + } + ] +}
\ No newline at end of file diff --git a/Fundamentals_Of_Engineering_Heat_And_Mass_Transfer/ch6.ipynb b/Fundamentals_Of_Engineering_Heat_And_Mass_Transfer/ch6.ipynb new file mode 100755 index 00000000..e94dc654 --- /dev/null +++ b/Fundamentals_Of_Engineering_Heat_And_Mass_Transfer/ch6.ipynb @@ -0,0 +1,244 @@ +{ + "metadata": { + "name": "", + "signature": "sha256:ffaa9591022d13ef65a41826984b020004775f9f4dff2ea59062ac5a8175fc23" + }, + "nbformat": 3, + "nbformat_minor": 0, + "worksheets": [ + { + "cells": [ + { + "cell_type": "heading", + "level": 1, + "metadata": {}, + "source": [ + "Chapter 6 : Fundamentals of convective heat transfer" + ] + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 6.2 Page No : 241" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math \n", + "\n", + "\n", + "# Variables\n", + "L = 1;\t\t\t#Length of the palte in m\n", + "W = 1;\t\t\t#Width of the plate in m\n", + "v = 2.5;\t\t\t#Velocity of air in m/s\n", + "Re = (5*10**5);\t\t\t#Reynolds number at the transition from laminar to turbulant\n", + "p = (0.85*10**-5);\t\t\t#Dynamic vismath.cosity in N.s/m**2\n", + "r = 1.12;\t\t\t#Density in kg/m**3\n", + "\n", + "# Calculations\n", + "x = (p*Re)/(r*v);\t\t\t#Calculated length in m\n", + "\n", + "# Results\n", + "print 'The actual length of the plate is %i m, which is less than %3.2f m'%(L,x)\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "The actual length of the plate is 1 m, which is less than 1.52 m\n" + ] + } + ], + "prompt_number": 1 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 6.6 Page No : 247" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "p = 0.8;\t\t\t#Dynamic viscosity in N.s/m**2\n", + "k = 0.15;\t\t\t#Thermal conductivity in W/m.K\n", + "Tb = 10;\t\t\t#Temperature of bearing in degree C\n", + "Ts = 30;\t\t\t#Temperature of the shaft in degree C\n", + "C = 0.002;\t\t\t#Clearance between bearig and shaft in m\n", + "U = 6;\t\t\t#Velocity in m/s\n", + "\n", + "# Calculations\n", + "qb = (((-p*U**2)/(2*C))-((k/C)*(Ts-Tb)))/1000;\t\t\t#Surface heat flux at the bearing in kW/m**2\n", + "qs = (((p*U**2)/(2*C))-((k/C)*(Ts-Tb)))/1000;\t\t\t#Surface heat flux at the shaft in kW/m**2\n", + "Tmax = Tb+(((p*U**2)/(2*k))*(0.604-0.604**2))+((Ts-Tb)*0.604);\t\t\t#Maximum temperature in degree C occurs when ymax = 0.604L\n", + "\n", + "# Results\n", + "print 'Maximum temperature rise is %3.3f degree C \\n \\\n", + "Heat fux to the bearing is %3.1f kW/m**2 \\n \\\n", + "Heat fux to the shaft is %3.1f kW/m**2'%(Tmax,qb,qs)\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Maximum temperature rise is 45.042 degree C \n", + " Heat fux to the bearing is -8.7 kW/m**2 \n", + " Heat fux to the shaft is 5.7 kW/m**2\n" + ] + } + ], + "prompt_number": 2 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 6.7 Page No : 257" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "D = 0.02;\t\t\t#I.D of the tube in m\n", + "Q = 1.5;\t\t\t#Flow rate in litres per minute\n", + "k = (1*10**-6);\t\t\t#kinematic vismath.cosity in m**2/s\n", + "\n", + "# Calculations\n", + "um = ((Q/60)*10**-3)/(3.14*(D**2/4));\t\t\t#Average velocity in m/s\n", + "Re = (um*D)/k;\t\t\t#Reynolds number\n", + "x = 0.05*D*Re;\t\t\t#Entry length in m\n", + "\n", + "# Results\n", + "print 'Re which is %3.0f less than 2300, the flow is laminar. \\n \\\n", + "Entry length is %3.3f m'%(Re,x)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Re which is 1592 less than 2300, the flow is laminar. \n", + " Entry length is 1.592 m\n" + ] + } + ], + "prompt_number": 3 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 6.8 Page No : 257" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "L = 3000;\t\t\t#Distance transported in m\n", + "D = 0.02;\t\t\t#I.D of the tube in m\n", + "Q = 1.5;\t\t\t#Flow rate in litres per minute\n", + "k = (1*10**-6);\t\t\t#kinematic vismath.cosity in m**2/s\n", + "pw = 1000;\t\t\t#Density of water in kg/m**3\n", + "\n", + "# Calculations\n", + "um = ((Q/60)*10**-3)/(3.14*(D**2/4));\t\t\t#Average velocity in m/s\n", + "Re = (um*D)/k;\t\t\t#Reynolds number\n", + "x = 0.05*D*Re;\t\t\t#Entry length in m\n", + "hL = ((64./Re)*L*um**2)/(2*D*9.81)\t\t\t#Head loss in m\n", + "P = (pw*9.81*(3.14/4)*D**2*um*hL);\t\t\t#Power required to maintain this flow rate in W\n", + "\n", + "# Results\n", + "print 'Head loss is %3.2f m \\n \\\n", + "Power required to maintain this flow rate is %3.4f W'%(hL,P)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Head loss is 1.95 m \n", + " Power required to maintain this flow rate is 0.4777 W\n" + ] + } + ], + "prompt_number": 5 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 6.9 Page No : 258" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "L = 100;\t\t\t#Length of rectangular duct in m\n", + "A = [0.02,0.025];\t\t\t#Area of duct in m**2\n", + "Tw = 40;\t\t\t#Temperature of water in degree C\n", + "v = 0.5;\t\t\t#Velocity of flow in m/s\n", + "k = (0.66*10**-6);\t\t\t#kinematic viscosity in m**2/s\n", + "p = 995;\t\t\t#Density of water in kg/m**3\n", + "\n", + "# Calculations\n", + "P = 2*(A[0]+A[1]);\t\t\t#Perimeter of the duct in m\n", + "Dh = (4*(A[0]*A[1]))/P\t\t\t#Hydraulic diameter of the duct in m\n", + "Re = (v*Dh)/k;\t\t\t#Reynolds number\n", + "f = 0.316*Re**(-0.25);\t\t\t#Friction factor \n", + "hL = (f*L*v**2)/(2*Dh*9.81);\t\t\t#Head loss in m\n", + "P = (hL*9.81*p)/10**4;\t\t\t#Pressure drop in smooth rectangular duct in 10**4 N/m**2\n", + "\n", + "# Results\n", + "print 'Pressure drop in smooth rectangular duct is %3.4f*10**4 N/m**2'%(P)\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Pressure drop in smooth rectangular duct is 1.5527*10**4 N/m**2\n" + ] + } + ], + "prompt_number": 4 + } + ], + "metadata": {} + } + ] +}
\ No newline at end of file diff --git a/Fundamentals_Of_Engineering_Heat_And_Mass_Transfer/ch7.ipynb b/Fundamentals_Of_Engineering_Heat_And_Mass_Transfer/ch7.ipynb new file mode 100755 index 00000000..2aa36e2e --- /dev/null +++ b/Fundamentals_Of_Engineering_Heat_And_Mass_Transfer/ch7.ipynb @@ -0,0 +1,1284 @@ +{ + "metadata": { + "name": "", + "signature": "sha256:9c4fb6b8e822716d4e29e95db1a4da7b71b979535df0e47c4729b7b08b5165ec" + }, + "nbformat": 3, + "nbformat_minor": 0, + "worksheets": [ + { + "cells": [ + { + "cell_type": "heading", + "level": 1, + "metadata": {}, + "source": [ + "Chapter 7 : Forced Convection Systems" + ] + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 7.1 Page No : 275" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math \n", + "\n", + "# Variables\n", + "Ta = 20;\t\t\t#Temperature of air in degree C\n", + "Tp = 134;\t\t\t#Temperature of heated plate in degree C\n", + "v = 3;\t\t\t#Velocity of flow in m/s\n", + "L = 2;\t\t\t#Length of plate in m\n", + "W = 1.5;\t\t\t#Width of plate in m\n", + "x = 0.4;\t\t\t#Distance of plane from the plate in m\n", + "k = (15.06*10**-6);\t\t\t#Kinematic vismath.cosity in m**2/s\n", + "\n", + "# Calculations\n", + "Re = (v*x)/k;\t\t\t#Reynold number\n", + "q = ((5*x)/math.sqrt(Re))*1000;\t\t\t#Thickness of boundary layer in mm\n", + "Cfx = (0.664/math.sqrt(Re))/10**-3;\t\t\t#Local skin friction coefficient *10**-3\n", + "\n", + "# Results\n", + "print 'Thickness of boundary layer is %3.1f mm Local skin friction coefficient is %3.2f*10**-3'%(q,Cfx)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Thickness of boundary layer is 7.1 mm Local skin friction coefficient is 2.35*10**-3\n" + ] + } + ], + "prompt_number": 2 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 7.2 Page No : 275" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "Ta = 20;\t\t\t#Temperature of air in degree C\n", + "Tp = 134;\t\t\t#Temperature of heated plate in degree C\n", + "v = 3;\t\t\t#Velocity of flow in m/s\n", + "L = 2;\t\t\t#Length of plate in m\n", + "W = 1.5;\t\t\t#Width of plate in m\n", + "x = 0.4;\t\t\t#Distance of plane from the plate in m\n", + "k = (15.06*10**-6);\t\t\t#Kinematic vismath.cosity in m**2/s\n", + "\n", + "# Calculations\n", + "Tf = (Ta+Tp)/2;\t\t\t#Film temperature in degree C\n", + "pw = 0.998;\t\t\t#Density of air at 77 degree C\n", + "Cp = 1009;\t\t\t#Specific heat of air at 77 degree C\n", + "kw = (20.76*10**-6);\t\t\t#Kinematic viscosity of air at 77 degree C\n", + "k = 0.03;\t\t\t#Thermal conductivity of air at 77 degree C\n", + "Pr = 0.697;\t\t\t#prantl number of air at 77 degree C\n", + "Re = (v*x)/kw;\t\t\t#Reynolds number\n", + "Nu = (0.332*Re**0.5*Pr**(1./3));\t\t\t#Nusselts number\n", + "h = (Nu*k)/x;\t\t\t#Heat transfer coefficient in W/m**2.K\n", + "h1 = (h*2);\t\t\t#Average value of heat transfer coefficient in W/m**2.K\n", + "Q = h1*x*W*(Tp-Ta);\t\t\t#Heat flow in W\n", + "Q1 = (2*Q);\t\t\t#Heat flow from both sides of the plate in W\n", + "\n", + "# Results\n", + "print 'Heat flow from both sides of the plate is %3.0f W'%(round(Q1,-1))\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Heat flow from both sides of the plate is 1450 W\n" + ] + } + ], + "prompt_number": 1 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 7.3 Page No : 282" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math\n", + "# Variables\n", + "Ta = 20;\t\t\t#Temperature of air in degree C\n", + "v = 3;\t\t\t#Velocity of flow in m/s\n", + "L = 2;\t\t\t#Length of plate in m\n", + "W = 1;\t\t\t#Width of plate in m\n", + "x1 = 0.3;\t\t\t#Initial point of the boundary layer in m\n", + "x2 = 0.8;\t\t\t#Final point of the boundary layer in m\n", + "p = 1.17;\t\t\t#Density of air at 20 degree C in kg/m**3\n", + "k = (15*10**-6);\t\t\t#Kinematic vismath.cosity in m**2/s\n", + "Re = (5*10**5);\t\t\t#Reynolds number at the transition frm laminar to turbulant\n", + "\n", + "# Calculations\n", + "x = (k*Re)/v;\t\t \t#Critical length in m\n", + "Rel = (v*L)/k; \t\t\t#Reynolds number\n", + "q = (4.64*L)/math.sqrt(Rel)*1000;\t\t\t#Boundary layer thickness at the trailing edge of plate in mm\n", + "ts = 1.292*(0.5*p*v**2)*math.sqrt(1./Rel);\t#Average shear stress in N/m**2\n", + "F = (2*L*ts);\t\t \t#Drag force on the two sides of the plate in N\n", + "q80 = (4.64*x2)/math.sqrt((v*x2)/k);\t\t\t#Boundray layer thickness at x = 0.8 m\n", + "q30 = (4.64*x1)/math.sqrt((v*x1)/k);\t\t\t#Boundray layer thickness at x = 0.3 m\n", + "m = ((5./8)*p*v*(q80-q30))/10**-3;\t\t\t#Mass flow of air in kg/s\n", + "\n", + "# Results\n", + "print 'Boundary layer thickness at the trailing edge of plate is % 3.2f mm \\n \\\n", + "Drag force on the two sides of the plate is %3.4f N \\n \\\n", + "Mass flow of air is %3.1f*10**-3 kg/s'%(q,F,m)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Boundary layer thickness at the trailing edge of plate is 14.67 mm \n", + " Drag force on the two sides of the plate is 0.0430 N \n", + " Mass flow of air is 7.9*10**-3 kg/s\n" + ] + } + ], + "prompt_number": 4 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 7.4 Page No : 283" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math\n", + "# Variables\n", + "P = 8.;\t\t\t#Pressure of air in kN/m**2\n", + "Ta = 250.;\t\t\t#Temperature of air in degree C\n", + "L = 1.;\t\t\t#Length of the palte in m\n", + "W = 0.3;\t\t\t#Width of the plate in m\n", + "v = 8.;\t\t\t#Velocity of air in m/s\n", + "Tp = 78.;\t\t\t#Temperature of plate in degree C\n", + "\n", + "# Calculations\n", + "Tf = (Ta+Tp)/2;\t\t\t#Film temperature in degree C\n", + "Cp = 1018;\t\t\t#Specific heat of air at 164 degree C and 1 atm pressure\n", + "kw = (30.8*10**-6);\t\t\t#Kinematic viscosity of air at 164 degree C and 1 atm pressure\n", + "k = 0.0364;\t\t\t#Thermal conductivity of air at 164 degree C and 1 atm pressure\n", + "Pr = 0.69;\t\t\t#prant number of air at 164 degree C and 1 atm pressure\n", + "k1 = kw*(101330/(P*1000));\t\t\t#Kinematic viscosity of air at 164 degree C and 8kN/m**2 pressure\n", + "Re = (v*L)/k1;\t\t\t#Reynolds number\n", + "h = 0.662*(k/L)*math.sqrt(Re)*Pr**(1./3);\t\t\t#Heat transfer coefficient in W/m.K\n", + "Q = 2*h*L*W*(Ta-Tp);\t\t\t#Rate of heat removal in W\n", + "\n", + "\n", + "# Results\n", + "print 'Rate of heat removal is %3.1f W'%(Q)\n", + "\n", + "#note : answer is slightly different because of rounding off error." + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Rate of heat removal is 314.7 W\n" + ] + } + ], + "prompt_number": 5 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 7.5 Page No : 286" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math\n", + "# Variables\n", + "P = 8.;\t\t\t#Pressure of air in kN/m**2\n", + "Ta = 250.;\t\t\t#Temperature of air in degree C\n", + "L = 1.;\t\t\t#Length of the palte in m\n", + "W = 0.3;\t\t\t#Width of the plate in m\n", + "v = 8.;\t\t\t#Velocity of air in m/s\n", + "Tp = 78.;\t\t\t#Temperature of plate in degree C\n", + "R = 287.;\t\t\t#Universal gas constant in J/kg.K\n", + "\n", + "# Calculations\n", + "Tf = (Ta+Tp)/2;\t\t\t#Film temperature in degree C\n", + "Cp = 1018;\t\t\t#Specific heat of air at 164 degree C and 1 atm pressure\n", + "kw = (30.8*10**-6);\t\t\t#Kinematic viscosity of air at 164 degree C and 1 atm pressure\n", + "k = 0.0364;\t\t\t#Thermal conductivity of air at 164 degree C and 1 atm pressure\n", + "Pr = 0.69;\t\t\t#prant number of air at 164 degree C and 1 atm pressure\n", + "k1 = kw*(101330/(P*1000));\t\t\t#Kinematic viscosity of air at 164 degree C and 8kN/m**2 pressure\n", + "Re = (v*L)/k1;\t\t\t#Reynolds number\n", + "h = 0.662*(k/L)*math.sqrt(Re)*Pr**(1./3);\t\t\t#Heat transfer coefficient in W/m.K\n", + "Q = 2*h*L*W*(Ta-Tp);\t\t\t#Rate of heat removal in W\n", + "p = (P*1000)/(R*(Tf+273));\t\t\t#Density in kg/m**3\n", + "St = (h/(p*Cp*v));\t\t\t#Stanton number\n", + "Cfx2 = (St*Pr**(2/3));\t\t\t#Colburn factor\n", + "ts = (Cfx2*p*v**2);\t\t\t#Average shear stress in N/m**2\n", + "D = (0.0186*W*L);\t\t\t#Drag force on one side of plate in N\n", + "D2 = (2*D)/10**-3;\t\t\t#Total drag force on both sides of plate in N\n", + "\n", + "# Results\n", + "print 'The drag force exerted on the plate is %3.2f*10**-3 N'%(D2)" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "The drag force exerted on the plate is 11.16*10**-3 N\n" + ] + } + ], + "prompt_number": 8 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 7.6 Page No : 289" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "L = 1;\t\t\t#Length of the palte in m\n", + "W = 1;\t\t\t#Width of the plate in m\n", + "Ts = 10;\t\t\t#Temperature of free strem air in degree C\n", + "v = 80;\t\t\t#Velocity of free stream air in m/s\n", + "\n", + "# Calculations\n", + "k = 0.025;\t\t\t #Thermal conductivity of air at 10 degree C \n", + "Pr = 0.72;\t\t\t #prant number of air at 10 degree C\n", + "v1 = (14.15*10**-6);\t\t\t #Kinematic viscosity of air at 10 degree C \n", + "Re = (v*L)/v1;\t\t\t #Reynolds number\n", + "q = 0.381*L*Re**(-1./5);\t\t \t#Thickness of the boundary layer at the trailing edge of the plate in m\n", + "Nu = (0.037*Re**(4./5)*Pr**(1./3));\t\t\t#Nusselts number\n", + "h = (Nu*k)/L; \t\t\t#Mean value of the heat transfer coefficient in W/m**2.K\n", + "\n", + "# Results\n", + "print 'Thickness of the boundary layer at the trailing edge of the plate is %3.4f m \\n \\\n", + "Mean value of the heat transfer coefficient is %3.0f W/m**2.K'%(q,h)" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Thickness of the boundary layer at the trailing edge of the plate is 0.0170 m \n", + " Mean value of the heat transfer coefficient is 209 W/m**2.K\n" + ] + } + ], + "prompt_number": 8 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 7.7 Page No : 290" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "Ta = 0.;\t\t \t#Temperature of air stream in degree C\n", + "Tp = 90.; \t\t#Temperature of heated plate in degree C\n", + "v = 75.;\t\t \t#Speed of air in m/s\n", + "L = 0.45;\t\t\t#Length of the palte in m\n", + "W = 0.6;\t\t\t#Width of the plate in m\n", + "Re = (5.*10**5);\t\t#Reynolds number at the transition from laminar to turbulant\n", + "\n", + "# Calculations\n", + "Tf = (Ta+Tp)/2;\t\t\t#Film temperature in degree C\n", + "k = 0.028;\t\t\t#Thermal conductivity of air at 10 degree C \n", + "Pr = 0.698;\t\t\t#prant number of air at 10 degree C\n", + "v1 = (17.45*10**-6);\t\t\t#Kinematic viscosity of air at 10 degree C \n", + "x = (Re*v1)/v;\t\t\t#Critical length in m\n", + "Rel = (v*L)/v1;\t\t\t#Reynolds number\n", + "Cfl = ((0.074/Rel**(1./5))-(1740/Rel))/10**-3;\t\t\t#Average value of friction coefficient *10**-3\n", + "Nu = ((0.037*Rel**(4./5))-870)*Pr**(1./3);\t\t\t#Nussults number\n", + "h = (Nu*k)/L;\t\t\t#Heat transfer coefficient in W/m**2.K\n", + "Q = (2*h*L*W*Tp);\t\t\t#Rate of energy dissipation in W\n", + "\n", + "# Results\n", + "print 'Average value of friction coefficient is %3.2f*10**-3 \\n \\\n", + "Heat transfer coefficient is %3.0f W/m**2.K \\n \\\n", + "Rate of energy dissipation is %i W'%(Cfl,h,Q)\n", + "\n", + "# note : book answer is wrong" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Average value of friction coefficient is 3.19*10**-3 \n", + " Heat transfer coefficient is 170 W/m**2.K \n", + " Rate of energy dissipation is 8281 W\n" + ] + } + ], + "prompt_number": 9 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 7.8 Page No : 296" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "D = 0.3;\t\t\t#Diameter of cylinder in m\n", + "L = 1.7;\t\t\t#Height of cylinder in m\n", + "Ts = 30.;\t\t\t#Surface temperature in degree C\n", + "v = 10.;\t\t\t#Speed of wind in m/s\n", + "Ta = 10.;\t\t\t#Temperature of air in degree C\n", + "\n", + "# Calculations\n", + "Tf = (Ta+Ts)/2;\t\t\t#Film temperature in degree C\n", + "k = 0.0259;\t\t\t#Thermal conductivity of air at 20 degree C \n", + "Pr = 0.707;\t\t\t#prant number of air at 20 degree C\n", + "v1 = (15*10**-6);\t\t\t#Kinematic viscosity of air at 20 degree C\n", + "Re = (v*D)/v1;\t\t\t#Reynolds number\n", + "Nu = 0.027*Re**0.805*Pr**(1./3)\t\t\t#Nusselts number\n", + "h = (Nu*k)/D;\t\t\t#Heat transfer coefficent in W/m**2.K\n", + "Q = (h*3.14*D*L*(Ts-Ta));\t\t\t#Rate of heat loss in W\n", + "\n", + "# Results\n", + "print 'Rate of heat loss is %3.1f W'%(Q)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Rate of heat loss is 1230.9 W\n" + ] + } + ], + "prompt_number": 11 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 7.9 Page No : 297" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "Ta = 27;\t\t\t#Temperature of air stream in degree C\n", + "v = 0.3;\t\t\t#Velodity of air in m/s\n", + "Q = 100;\t\t\t#Poer of electric bulb in W\n", + "Te = 127;\t\t\t#Temperature of electric bulb in degree C\n", + "D = 0.06;\t\t\t#Diameter of sphere in m\n", + "\n", + "# Calculations\n", + "Tf = (Ta+Te)/2;\t\t\t#Film temperature in degree C\n", + "k = 0.03;\t\t\t#Thermal conductivity of air at 77 degree C \n", + "Pr = 0.697;\t\t\t#prant number of air at 77 degree C\n", + "v1 = (2.08*10**-5);\t\t\t#Kinematic viscosity of air at 77 degree C\n", + "Re = (v*D)/v1;\t\t\t#Reynolds number\n", + "h = (k*0.37*Re**0.6)/D;\t\t\t#Heat transfer coefficient in W/m**2.K\n", + "Q = (h*3.14*D**2*(Te-Ta));\t\t\t#Heat transfer rate in W\n", + "Qp = (Q*100)/100;\t\t\t#Percentage of heat lost by forced convection \n", + "\n", + "# Results\n", + "print \"Heat transfer rate is %3.2f W \\n \\\n", + "Percentage of power lost due to convection is %3.2f percent\"%(Q,Qp)" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Heat transfer rate is 12.10 W \n", + " Percentage of power lost due to convection is 12.10 percent\n" + ] + } + ], + "prompt_number": 12 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 7.10 Page No : 297" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math\n", + "# Variables\n", + "D = 0.015;\t\t\t#Diamter of copper bus bar in m\n", + "Ta = 20;\t\t\t#Temperature of air stream in degree C\n", + "v = 1;\t\t\t#Velocity of air in m/s\n", + "Ts = 80;\t\t\t#Surface temperature in degree C\n", + "p = 0.0175;\t\t\t#Resistivity of copper in ohm mm**2/m\n", + "\n", + "# Calculations\n", + "Tf = (Ta+Ts)/2;\t\t\t#Film temperature in degree C\n", + "k = 0.02815;\t\t\t#Thermal conductivity of air at 50 degree C \n", + "Pr = 0.703;\t\t\t#prant number of air at 50 degree C\n", + "v1 = (18.9*10**-6);\t\t\t#Kinematic viscosity of air at 50 degree C\n", + "Re = (v*D)/v1;\t\t\t#Reynolds number\n", + "Nu = 0.3+(((0.62*math.sqrt(Re)*Pr**(1./3))/(1+(0.4/Pr)**(2./3))**(1./4))*(1+(Re/28200.)**(5./8))**(4./5));\t\t\t#Nusselts number\n", + "h = (Nu*k)/D;\t\t\t#Heat transfer coefficent in W/m**2.K\n", + "I = 1000*3.14*D*math.sqrt((h*(Ts-Ta)*D)/(4*p));\t\t\t#Current in A\n", + "\n", + "# Results\n", + "print 'Heat transfer coefficient between the bus bar and cooling air is %3.2f W/m**2.K \\n \\\n", + "Maximum admissible current intensity for the bus bar is %3.0f A'%(h,I)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Heat transfer coefficient between the bus bar and cooling air is 28.31 W/m**2.K \n", + " Maximum admissible current intensity for the bus bar is 899 A\n" + ] + } + ], + "prompt_number": 14 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 7.11 Page No : 298" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "Ta = 30;\t\t\t#Temperature of air stream in degree C\n", + "v = 25;\t\t\t#Velocity of stream in m/s\n", + "x = 0.05;\t\t\t#Side of a square in m\n", + "D = 0.05;\t\t\t#Diameter of circular cylinder in m\n", + "Ts = 124;\t\t\t#Surface temperature in degree C\n", + "\n", + "# Calculations\n", + "Tf = (Ta+Ts)/2;\t\t\t#Film temperature in degree C\n", + "k = 0.03;\t\t\t#Thermal conductivity of air at 77 degree C \n", + "Pr = 0.7;\t\t\t#prantL number of air at 77 degree C\n", + "v1 = (20.92*10**-6);\t\t\t#Kinematic viscosity of air at 77 degree C\n", + "Re = (v*D)/v1;\t\t\t#Reynolds number\n", + "Nu1 = 0.027*Re**0.805*Pr**(1./3);\t\t\t#Nussults number for circulat tube\n", + "h1 = (Nu1*k)/D;\t\t\t#Heat tansfer coefficient for circular tube in W/m**2.K\n", + "Nu2 = 0.102*Re**0.675*Pr**(1./3);\t\t\t#Nussults number for square tube\n", + "h2 = (Nu2*k)/D;\t\t\t#Heat transfer coefficient for square tube in W/m**2.K\n", + "\n", + "# Results\n", + "print 'Heat transfer coefficient for circular tube is %3.1f W/m**2.K \\n \\\n", + "Heat transfer coefficient for square tube is %3.2f W/m**2.K'%(h1,h2)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Heat transfer coefficient for circular tube is 100.7 W/m**2.K \n", + " Heat transfer coefficient for square tube is 91.02 W/m**2.K\n" + ] + } + ], + "prompt_number": 15 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 7.12 Page No : 302" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "n = 7;\t\t\t#Number of rows of tube\n", + "Ta = 15;\t\t\t#Temperature of air in degree C\n", + "v = 6;\t\t\t#Velocity of air in m/s\n", + "ST = 0.0205;\t\t\t#Transverse pitch in m\n", + "SD = 0.0205;\t\t\t#Longitudinal pitch in m\n", + "D = 0.0164;\t\t\t#Outside diameter of the tube in m\n", + "Ts = 70;\t\t\t#Surface temperature in degree C\n", + "\n", + "# Calculations\n", + "Tf = (Ta+Ts)/2;\t\t\t#Film temperature in degree C\n", + "k = 0.0274;\t\t\t#Thermal conductivity of air at 42.5 degree C \n", + "Pr = 0.705;\t\t\t#prant number of air at 42.5 degree C\n", + "v1 = (17.4*10**-6);\t\t\t#Kinematic viscosity of air at 42.5 degree C\n", + "p = 1.217;\t\t\t#Density in kg/m**3\n", + "vmax = (v*ST)/(ST-D);\t\t\t#Maximum velocity in m/s\n", + "Re = (vmax*D)/v1;\t\t\t#Reynolds number\n", + "Nu = (1.13*0.518*Re**0.556*Pr**(1./3))*0.97;\t\t\t#Nusselts number\n", + "h = (Nu*k)/D;\t\t\t#Heat transfer coefficent in W/m**2.K\n", + "f = 0.4;\t\t\t#From Fig. 7.10 on page no 303 \n", + "g = 1.04;\t\t\t#From Fig. 7.10 on page no 303\n", + "dp = (n*f*p*vmax**2*g)/2;\t\t\t#Pressure drop in N/m**2\n", + "\n", + "# Results\n", + "print 'Heat transfer coefficent is %3.2f W/m**2.K \\n \\\n", + "Pressure drop is %3.0f N/m**2'%(h,dp)\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Heat transfer coefficent is 252.04 W/m**2.K \n", + " Pressure drop is 1595 N/m**2\n" + ] + } + ], + "prompt_number": 16 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 7.13 Page No : 304" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "n = 7;\t\t\t#Number of rows of tube\n", + "Ta = 15;\t\t\t#Temperature of air in degree C\n", + "v = 6;\t\t\t#Velocity of air in m/s\n", + "ST = 0.0205;\t\t\t#Transverse pitch in m\n", + "SD = 0.0205;\t\t\t#Longitudinal pitch in m\n", + "D = 0.0164;\t\t\t#Outside diameter of the tube in m\n", + "Ts = 70;\t\t\t#Surface temperature in degree C\n", + "\n", + "# Calculations\n", + "Tf = (Ta+Ts)/2;\t\t\t#Film temperature in degree C\n", + "k = 0.0253;\t\t\t#Thermal conductivity of air at 15 degree C \n", + "Pr = 0.710;\t\t\t#prant number of air at 15 degree C\n", + "v1 = (14.82*10**-6);\t\t\t#Kinematic viscosity of air at 15 degree C\n", + "p = 1.217;\t\t\t#Density in kg/m**3\n", + "Pr1 = 0.701;\t\t\t#prant number of air at 70 degree C\n", + "vmax = (v*ST)/(ST-D);\t\t\t#Maximum velocity in m/s\n", + "Re = (vmax*D)/v1;\t\t\t#Reynolds number\n", + "Nu = 0.35*Re**0.6*(Pr/Pr1)**0.25;\t\t\t#\n", + "h = (Nu*k)/D;\t\t\t#Heat transfer coefficient in W/m**2.K\n", + "\n", + "# Results\n", + "print ' Heat transfer coefficient is %3.1f W/m**2 K'%(h) \n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + " Heat transfer coefficient is 279.5 W/m**2 K\n" + ] + } + ], + "prompt_number": 1 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 7.14 Page No : 305" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "m = 0.314;\t\t\t#Mass flow rate of air in m**3/s\n", + "n1 = 7;\t\t\t#Number of tubes in the direction of flow\n", + "n2 = 8;\t\t\t#Number of tubes perpendicular to the direction of flow\n", + "L = 1.25;\t\t\t#Length of each tube in m\n", + "D = 0.019;\t\t\t#Outer diameter in m\n", + "ST = 0.0286;\t\t\t#Transverse pitch in m\n", + "SD = 0.038;\t\t\t#Longitudinal pitch in m\n", + "Ta = 200;\t\t\t#Temperature of air in degree C\n", + "Ts = 96;\t\t\t#Surface temperature in degree C\n", + "\n", + "# Calculations\n", + "Tf = (Ta+Ts)/2;\t\t\t#Film temperature in degree C\n", + "k = 0.039;\t\t\t#Thermal conductivity of air at 15 degree C \n", + "Pr = 0.688;\t\t\t#prantl number of air at 15 degree C\n", + "v1 = (3*10**-5);\t\t\t#Kinematic vismath.cosity of air at 15 degree C\n", + "vmax = (m/((ST*n2*L)-(D*n2*L)));\t\t\t#Maximum velocity in m/s\n", + "Re = (vmax*D)/v1;\t\t\t#Reynolds number\n", + "Nu = (0.299*Re**0.602*Pr**(1./3));\t\t\t#Nusselts number\n", + "X = 0.96;\t\t\t#From Table 7.5 on page no.302\n", + "Nux = (X*Nu);\t\t\t#Average nusselts number\n", + "h = (Nux*k)/D;\t\t\t#Convective heat transfer coefficient in W/m**2.K\n", + "\n", + "# Results\n", + "print 'Convective heat transfer coefficient is %3.2f W/m**2.K'%(h)\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Convective heat transfer coefficient is 51.58 W/m**2.K\n" + ] + } + ], + "prompt_number": 18 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 7.15 Page No : 310" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "D = 0.2;\t\t\t#Diameter of pipeline in m\n", + "\t\t\t#velocity profile is given by u = 96r-190r**2 m/s\n", + "\t\t\t#Temperature profile is given by T = 100(1-2r) degree C\n", + "\n", + "# Calculations\n", + "vmax = (64*(D/2))-(95*(D/2)**2);\t\t\t#Mean velocity in m/s\n", + "T = (2/(vmax*(D/2)**2))*(((9600*(D/2)**3)/3)-((38200*(D/2)**4)/4)+((38000*(D/2)**5)/5));\t\t\t#Average temperature of the fluid in degree C\n", + "\n", + "# Results\n", + "print 'Average temperature of the fluid is %3.2f degree C'%(T)\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Average temperature of the fluid is 85.17 degree C\n" + ] + } + ], + "prompt_number": 19 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 7.16 Page No : 311" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "Di = 0.025;\t\t\t#I.D of the tube in m\n", + "Do = 0.04;\t\t\t#O.D of the tube in m\n", + "m = 5.;\t\t\t#Mass flow rate of water in kg/m\n", + "T = [20.,70.];\t\t\t#Temperature at entry and exit of water in degree C\n", + "Q = 10.**7;\t\t\t#Heat in W/m**3\n", + "Ts = 80.;\t\t\t#Surface temperature in degree C\n", + "Cp = 4179.;\t\t\t#Specific heat of water in J/kg.K\n", + "\n", + "# Calculations\n", + "Tb = (T[0]+T[1])/2;\t\t\t#Film temperature in degree C\n", + "L = ((4*(m/60)*Cp*(T[1]-T[0]))/(3.14*(Do**2-Di**2)*Q));\t\t\t#Length of tube in m\n", + "qs = ((Q*(Do**2-Di**2))/(4*Di));\t\t\t#Heat flux at the surface in W/m**2\n", + "h = (qs/(Ts-T[1]));\t\t\t#Heat transfer coefficient at the outlet in W/m**2.K\n", + "\n", + "\n", + "# Results\n", + "print 'Length of tube is %3.3f m \\nHeat transfer coefficient at the outlet is %3.0f W/m**2.K'%(L,h)\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Length of tube is 2.275 m \n", + "Heat transfer coefficient at the outlet is 9750 W/m**2.K\n" + ] + } + ], + "prompt_number": 1 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 7.17 Page No : 312" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "k = 0.175;\t\t\t#Thermal conductivity in W/m.K\n", + "Di = 0.006;\t\t\t#I.D of the tube in m\n", + "L = 8;\t\t\t#Length of the tube in m\n", + "dT = 50;\t\t\t#Mean temperature difference in degree C\n", + "\n", + "# Calculations\n", + "h = (3.66*k)/Di;\t\t\t#Heat transfer coefficient in W/m**2.K\n", + "Q = (h*3.14*Di*L*dT);\t\t\t#Heat transfer rate in W\n", + "\n", + "# Results\n", + "print 'Heat transfer coefficient is %3.2f W/m**2.K Heat transfer rate is %3.0f W'%(h,Q)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Heat transfer coefficient is 106.75 W/m**2.K Heat transfer rate is 804 W\n" + ] + } + ], + "prompt_number": 21 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 7.18 Page No : 312" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "Ti = 25;\t\t\t#Initial temperature of water in degree C\n", + "D = 0.05;\t\t\t#Diamter of the tube in m\n", + "Re = 1600;\t\t\t#Reynolds number\n", + "q = 800;\t\t\t#Heat flux in W/m\n", + "Tf = 50;\t\t\t#Final temperature of water in degree C\n", + "\n", + "# Calculations\n", + "k = 0.61;\t\t\t#Thermal conductivity of water at 25 degree C in W/m.K\n", + "u = (915*10**-6);\t\t\t#Dynamic viscosity in N.s/m**2\n", + "m = (Re*3.14*D*u)/4;\t\t\t#Mass flow rate of water in kg/s\n", + "h = (4.364*k)/D;\t\t\t#Heat transfer coefficient in W/m**2.K\n", + "qs = (q/(3.14*D));\t\t\t#Constant heat flux in W/m**2\n", + "Cp = 4178;\t\t\t#Specific heat of water in J/kg.K\n", + "L = ((m*Cp*(Tf-Ti))/q);\t\t\t#Length of the tube in m\n", + "\n", + "# Results\n", + "print 'Average heat transfer coefficient is %3.2f W/m**2.K \\n \\\n", + "Length of the tube is %3.3f m'%(h,L)\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Average heat transfer coefficient is 53.24 W/m**2.K \n", + " Length of the tube is 7.502 m\n" + ] + } + ], + "prompt_number": 22 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 7.19 Page No : 314" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "Di = 0.015;\t\t\t#I.D of the tube in m\n", + "Tb = 60;\t\t\t#Temperature of the tube in degree C\n", + "m = 10;\t\t\t#Flow rate of water in ml/s\n", + "Ti = 20;\t\t\t#Temperature of water at entry in degree C\n", + "x = 1;\t\t\t#Dismath.tance form the plane in m\n", + "Tx = 34;\t\t\t#Temperature of water at 1 m dismath.tance in degree C\n", + "\n", + "# Calculations\n", + "Tbm = (Ti+Tx)/2;\t\t\t#Mean value of bulk temperature in degree C\n", + "pw = 997;\t\t\t#Density of air at 27 degree C in kg/m**3\n", + "Cp = 4180;\t\t\t#Specific heat of air at 27 degree C in J/kg.K\n", + "u = (855*10**-6);\t\t\t#Dynamic vismath.cosity of air at 27 degree C in N.s/m**2\n", + "k = 0.613;\t\t\t#Thermal conductivity of air at 27 degree C in W/m.K\n", + "Pr = 5.83;\t\t\t#prantl number of air at 27 degree C\n", + "us = (464*10**-6);\t\t\t#Dynamic vismath.cosity of air at 60 degree C in Ns/m**2\n", + "um = (m*10**-6)/((3.14/4)*Di**2);\t\t\t#Mean speed in m/s\n", + "Re = (pw*um*Di)/u;\t\t\t#Reynolds number\n", + "Nu = 3.66+((0.0668*(Di/x)*Re*Pr)/(1+(0.04*((Di/x)*Re*Pr)**(2./3))));\t\t\t#Nusselts number in Haussen correlation\n", + "Nux = (1.86*((Re*Pr)/(x/Di))**(1./3)*(u/us)**0.14);\t\t\t#Nusselsts number in Sieder - Tate correlation \n", + "\n", + "# Results\n", + "print 'Nusselts number in Haussen correlation is %3.2f \\n \\\n", + "Nusselsts number in Sieder - Tate correlation is %3.3f'%(Nu,Nux)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Nusselts number in Haussen correlation is 6.90 \n", + " Nusselsts number in Sieder - Tate correlation is 8.964\n" + ] + } + ], + "prompt_number": 2 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 7.20 Page No : 318" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "Tw = 50;\t\t\t#Temperature of water in degree C\n", + "Di = 0.005;\t\t\t#Inner diameter of the tube in m\n", + "L = 0.5;\t\t\t#Length of the tube in m\n", + "v = 1;\t\t\t#Mean velocity in m/s\n", + "Ts = 30;\t\t\t#Surface temperature in degree C\n", + "\n", + "# Calculations\n", + "Tf = (Tw+Ts)/2;\t\t\t#Film temperature in degree C\n", + "k = 0.039;\t\t\t#Thermal conductivity of air at 15 degree C \n", + "Pr = 0.688;\t\t\t#prant number of air at 15 degree C\n", + "p = 990;\t\t\t#Density of air at 50 degree C in kg/m**3\n", + "Cp = 4178;\t\t\t#Specific heat of air at 50 degree C in J/kg.K\n", + "v1 = (5.67*10**-7);\t\t\t#Kinematic viscosity of air at 50 degree C\n", + "v2 = (6.57*10**-7);\t\t\t#Kinematic viscosity of air at 40 degree C\n", + "Re = (v*Di)/v1;\t\t\t#Reynolds number\n", + "h = ((0.316/8)*((v*Di*10)/v2)**(-0.25)*p*Cp*v*(4.34)**(-2./3));\t\t\t#Heat transfer coefficient umath.sing the Colburn anamath.logy in W/m**2.K\n", + "\n", + "# Results\n", + "print 'Heat transfer coefficient using the Colburn analogy is %3.0f W/m**2.K'%(h)\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Heat transfer coefficient using the Colburn analogy is 3697 W/m**2.K\n" + ] + } + ], + "prompt_number": 2 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 7.21 Page No : 319" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "Ti = 50;\t\t\t#Temperature of water at inlet in degree C\n", + "D = 0.015;\t\t\t#Diameter of tube in m\n", + "L = 3;\t\t\t#Length of the tube in m\n", + "v = 1;\t\t\t#Velocity of flow in m/s\n", + "Tb = 90;\t\t\t#Temperature of tube wall in degree C\n", + "Tf = 64;\t\t\t#Exit temperature of water in degree C\n", + "\n", + "# Calculations\n", + "Tm = (Ti+Tf)/2;\t\t\t#Bulk mean temperature in degree C\n", + "p = 990;\t\t\t#Density of air at 57 degree C in kg/m**3\n", + "Cp = 4184;\t\t\t#Specific heat of air at 57 degree C in J/kg.K\n", + "u = (0.517*10**-6);\t\t\t#Kinematic viscosity of air at 57 degree C in m**2/s\n", + "k = 0.65;\t\t\t#Thermal conductivity of air at 57 degree C in W/m.K\n", + "Pr = 3.15;\t\t\t#prantl number of air at 57 degree C \n", + "Re = (v*D)/u;\t\t\t#Reynolds number\n", + "Nu = (0.023*Re**(4./5)*Pr**0.4);\t\t\t#Nusselts number\n", + "h = (Nu*k)/D;\t\t\t#Heat transfer coefficient in W/m**2.K\n", + "Q = (h*3.14*D*L*(Tb-Tm))/1000;\t\t\t#Rate of heat transfered in kW\n", + "\n", + "# Results\n", + "print 'Heat transfer coefficient is %3.0f W/m**2.K \\nRate of heat transfered is %3.2f kW'%(h,Q)\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Heat transfer coefficient is 5861 W/m**2.K \n", + "Rate of heat transfered is 27.33 kW\n" + ] + } + ], + "prompt_number": 27 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 7.22 Page No : 320" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "D = 0.022;\t\t\t#Diamter of the tube in m\n", + "v = 2;\t\t\t#Average velocity in m/s\n", + "Tw = 95;\t\t\t#Temperature of tube wall in degree C\n", + "T = [15,60];\t\t\t#Initial and final temperature of water in degree C\n", + "\n", + "# Calculations\n", + "Tm = (T[0]+T[1])/2;\t\t\t#Bulk mean temperature in degree C\n", + "p = 990;\t\t\t#Density of air at 37.5 degree C in kg/m**3\n", + "Cp = 4160;\t\t\t#Specific heat of air at 37.5 degree C in J/kg.K\n", + "u = (0.69*10**-3);\t\t\t#Dynamic viscosity of air at 37.5 degree C in Ns/m**2\n", + "k = 0.63;\t\t\t#Thermal conductivity of air at 37.5 degree C in W/m.K\n", + "us = (0.3*10**-3);\t\t\t#Dynamic viscosity of air at 37.5 degree C in Ns/m**2\n", + "Re = (p*v*D)/u;\t\t\t#Reynolds number\n", + "Pr = (u*Cp)/k;\t\t\t#Prantl number\n", + "Nu = (0.027*Re**(4./5)*Pr**(1./3)*(u/us)**0.14);\t\t\t#Nusselts number\n", + "h = (Nu*k)/D;\t\t\t#Heat transfer coefficient in W/m**2.K\n", + "\n", + "# Results\n", + "print 'Heat transfer coefficient is %3.0f W/m**2.K'%(h)\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Heat transfer coefficient is 9969 W/m**2.K\n" + ] + } + ], + "prompt_number": 28 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 7.23 Page No : 320" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "D = 0.05;\t\t\t#Diamter of the tube in m\n", + "T = 147;\t\t\t#Average temperature in degree C\n", + "v = 0.8;\t\t\t#Flow vwlocity in m/s\n", + "Tw = 200;\t\t\t#Wall temperature in degree C\n", + "L = 2;\t\t\t#Length of the tube in m\n", + "\n", + "# Calculations\n", + "p = 812.1;\t\t\t#Density in kg/m**3 of oil at 147 degree C\n", + "Cp = 2427;\t\t\t#Specific heat of oil at 147 degree C in J/kg.K\n", + "u = (6.94*10**-6);\t\t\t#Kinematic viscosity of oil at 147 degree C in m**2/s\n", + "k = 0.133;\t\t\t#Thermal conductivity of oil at 147 degree C in W/m.K\n", + "Pr = 103;\t\t\t#prantl number of oil at 147 degree C \n", + "Re = (v*D)/u;\t\t\t#Reynolds number\n", + "Nu = (0.036*Re**0.8*Pr**(1./3)*(D/L)**0.055);\t\t\t#Nussults number\n", + "h = (Nu*k)/D;\t\t\t#Average heat transfer coefficient in W/m**2.K\n", + "\n", + "# Results\n", + "print 'Average heat transfer coefficient is %3.1f W/m**2.K'%(h)" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Average heat transfer coefficient is 373.7 W/m**2.K\n" + ] + } + ], + "prompt_number": 29 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 7.24 Page No : 321" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "D = [0.4,0.8];\t\t\t#Dimensions of the trunk duct in m\n", + "Ta = 20;\t\t\t#Temperature of air in degree C\n", + "v = 7;\t\t\t#Velocity of air in m/s\n", + "v1 = (15.06*10**-6);\t\t\t#Kinematic viscosity in m**2/s\n", + "a = (7.71*10**-2);\t\t\t#Thermal diffusivity in m**2/h\n", + "k = 0.0259;\t\t\t#Thermal conductivity in W/m.K\n", + "\n", + "# Calculations\n", + "Dh = (4*(D[0]*D[1]))/(2*(D[0]+D[1]));\t\t\t#Value of Dh in m\n", + "Re = (v*Dh)/v1;\t\t\t#Reynolds number\n", + "Pr = (v1/a)*3600;\t\t\t#Prantl number\n", + "Nu = (0.023*Re**(4./5)*Pr**0.4);\t\t\t#Nussults number\n", + "h = (Nu*k)/Dh;\t\t\t#Heat transfer coefficient in W/m**2.K\n", + "Q = (h*(2*(D[0]+D[1])));\t\t\t#Heat leakage per unit length per unit difference in W\n", + "\n", + "# Results\n", + "print 'Heat leakage per unit length per unit difference is %3.2f W'%(Q)" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Heat leakage per unit length per unit difference is 48.14 W\n" + ] + } + ], + "prompt_number": 31 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 7.25 Page No : 322" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "Di = 0.03125;\t\t\t#I.D of the annulus in m\n", + "Do = 0.05;\t\t\t#O.D of the annulus in m\n", + "Ts = 50;\t\t\t#Outer surface temperature in degree C\n", + "Ti = 16;\t\t\t#Temeperature at which air enters in degree C\n", + "Tf = 32;\t\t\t#Temperature at which air exits in degree C\n", + "v = 30;\t\t\t#Flow rate in m/s\n", + "\n", + "# Calculations\n", + "Tb = (Ti+Tf)/2;\t\t\t#Mean bulk temperature of air in degree C\n", + "p = 1.614;\t\t\t#Density in kg/m**3 of air at 24 degree C\n", + "Cp = 1007;\t\t\t#Specific heat of air at 24 degree C in J/kg.K\n", + "u = (15.9*10**-6);\t\t\t#Kinematic viscosity of air at 24 degree C in m**2/s\n", + "k = 0.0263;\t\t\t#Thermal conductivity of air at 24 degree C in W/m.K\n", + "Pr = 0.707;\t\t\t#prantl number of air at 24 degree C\n", + "Dh = (4*(3.14/4)*(Do**2-Di**2))/(3.14*(Do+Di));\t\t\t#Hydraulic diameter in m\n", + "Re = (v*Dh)/u;\t\t\t#Reynolds number\n", + "Nu = (0.023*Re**0.8*Pr**0.4);\t\t\t#Nussults number\n", + "h = (Nu*k)/Dh;\t\t\t#Heat transfer coefficient in W/m**2.K\n", + "\n", + "# Results\n", + "print 'Heat transfer coefficient is %3.1f W/m**2.K'%(h)\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Heat transfer coefficient is 122.3 W/m**2.K\n" + ] + } + ], + "prompt_number": 33 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 7.26 Page No : 324" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "T = [120,149];\t\t\t#Initail and final temperatures in degree C\n", + "m = 2.3;\t\t\t#Mass flow rate in kg/s\n", + "D = 0.025;\t\t\t#Diameter of the tube in m\n", + "Ts = 200;\t\t\t#Surface temperature in degree C\n", + "\n", + "# Calculations\n", + "Tb = (T[0]+T[1])/2;\t\t\t#Bulk mean temperature in degree C\n", + "p = 916;\t\t\t#Density in kg/m**3 of air at 134.5 degree C\n", + "Cp = 1356.6;\t\t\t#Specific heat of air at 134.5 degree C in J/kg.K\n", + "u = (0.594*10**-6);\t\t\t#Kinematic viscosity of air at 134.5 degree C in m**2/s\n", + "k = 84.9;\t\t\t#Thermal conductivity of air at 134.5 degree C in W/m.K\n", + "Pr = 0.0087;\t\t\t#prantl number of air at 134.5 degree C\n", + "Q = (m*Cp*(T[1]-T[0]))/1000;\t\t\t#Total heat transfer in kW\n", + "v = (m/(p*(3.14/4)*D**2));\t\t\t#Velocity of flow in m/s\n", + "Re = (v*D)/u;\t\t\t#Reynolds number\n", + "Pe = (Pr*Re);\t\t\t#Peclet number\n", + "Nu = (4.82+(0.0185*Pe**0.827));\t\t\t#Nussults number\n", + "h = (Nu*k)/D;\t\t\t#Heat transfer coefficient in W/m**2.K\n", + "L = ((Q*1000)/(h*3.14*D*(Ts-Tb)));\t\t\t#Minimum length of the tube in m if the wall temperature is not to exceed 200 degree C\n", + "\n", + "# Results\n", + "print 'Minimum length of the tube if the wall temperature is not to exceed 200 degree C is %3.3f m'%(L)\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Minimum length of the tube if the wall temperature is not to exceed 200 degree C is 0.361 m\n" + ] + } + ], + "prompt_number": 34 + } + ], + "metadata": {} + } + ] +}
\ No newline at end of file diff --git a/Fundamentals_Of_Engineering_Heat_And_Mass_Transfer/ch8.ipynb b/Fundamentals_Of_Engineering_Heat_And_Mass_Transfer/ch8.ipynb new file mode 100755 index 00000000..532f0847 --- /dev/null +++ b/Fundamentals_Of_Engineering_Heat_And_Mass_Transfer/ch8.ipynb @@ -0,0 +1,790 @@ +{ + "metadata": { + "name": "", + "signature": "sha256:ca5009f0cb9dd781f90e694bd80e1f1d823182523e44edb65991cb3279963181" + }, + "nbformat": 3, + "nbformat_minor": 0, + "worksheets": [ + { + "cells": [ + { + "cell_type": "heading", + "level": 1, + "metadata": {}, + "source": [ + "Chapter 8 : Natural Convection" + ] + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 8.1 Page No : 340" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math \n", + "\n", + "# Variables\n", + "L = 0.3;\t\t\t#Length of the glass plate in m\n", + "Ta = 27;\t\t\t#Temperature of air in degree C\n", + "Ts = 77;\t\t\t#Surface temperature in degree C\n", + "v = 4;\t\t\t#Velocity of air in m/s\n", + "\n", + "# Calculations\n", + "Tf = (Ta+Ts)/2;\t\t\t#Film temperature in degree C\n", + "k = 0.02815;\t\t\t#Thermal conductivity in W/m.K\n", + "v1 = (18.41*10**-6);\t\t\t#Kinematic viscosity in m**2/s\n", + "Pr = 0.7;\t\t\t#Prantl number\n", + "b = (3.07*10**-3);\t\t\t#Coefficient of thermal expansion in 1./K\n", + "Gr = (9.81*b*(Ts-Ta)*L**3)/v1**2;\t\t\t#Grashof number\n", + "q = L*((3.93*(1./math.sqrt(Pr))*(0.952+Pr)**0.25*Gr**(-0.25)));\t\t\t#Boundary layer thickness at the trailing edge of the plate in free convection in m\n", + "Re = (v*L)/v1;\t\t\t#Reynolds number\n", + "q1 = (5*L)/math.sqrt(Re);\t\t\t#Boundary layer thickness at the trailing edge of the plate in forced convection in m\n", + "\n", + "# Results\n", + "print 'Boundary layer thickness at the trailing edge of the plate in free convection is % 3.4f m \\\n", + "\\nBoundary layer thickness at the trailing edge of the plate in forced convection is %3.4f m'%(q,q1) \n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Boundary layer thickness at the trailing edge of the plate in free convection is 0.0153 m \n", + "Boundary layer thickness at the trailing edge of the plate in forced convection is 0.0059 m\n" + ] + } + ], + "prompt_number": 2 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 8.2 Page No : 341" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math\n", + "# Variables\n", + "L = 0.3;\t\t\t#Length of the glass plate in m\n", + "Ta = 27;\t\t\t#Temperature of air in degree C\n", + "Ts = 77;\t\t\t#Surface temperature in degree C\n", + "v = 4;\t\t\t#Velocity of air in m/s\n", + "\n", + "# Calculations\n", + "Tf = (Ta+Ts)/2;\t\t\t#Film temperature in degree C\n", + "k = 0.02815;\t\t\t#Thermal conductivity in W/m.K\n", + "v1 = (18.41*10**-6);\t\t\t#Kinematic viscosity in m**2/s\n", + "Pr = 0.7;\t\t\t#Prantl number\n", + "b = (3.07*10**-3);\t\t\t#Coefficient of thermal expansion in 1./K\n", + "Gr = (9.81*b*(Ts-Ta)*L**3)/v1**2;\t\t\t#Grashof number\n", + "Re = (v*L)/v1;\t\t\t#Reynolds number\n", + "Nu = (0.677*math.sqrt(Pr)*(0.952+Pr)**(-0.25)*Gr**0.25);\t\t\t#Nusselts number\n", + "h = (Nu*k)/L;\t\t\t#Heat transfer coefficient for natural convection in W/m**2.K\n", + "Nux = (0.664*math.sqrt(Re)*Pr**(1./3));\t\t\t#Nusselts number\n", + "hx = (Nux*k)/L;\t\t\t#Heat transfer coefficient for forced convection in W/m**2.K\n", + "\n", + "# Results\n", + "print 'Heat transfer coefficient for natural convection is %3.1f W/m**2.K \\n \\\n", + "Heat transfer coefficient for forced convection is %3.2f W/m**2.K'%(h,hx)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Heat transfer coefficient for natural convection is 4.9 W/m**2.K \n", + " Heat transfer coefficient for forced convection is 14.12 W/m**2.K\n" + ] + } + ], + "prompt_number": 3 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 8.3 Page No : 343" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "L = 0.609;\t\t\t#Height of the metal plate in m\n", + "Ts = 161.;\t\t\t#Temperature of the wall in degree C\n", + "Ta = 93.;\t\t\t#Temperature of air in degree C\n", + "\n", + "# Calculations\n", + "Tf = (Ts+Ta)/2;\t\t\t#Film temperature in degree C\n", + "k = 0.0338;\t\t\t#Thermal conductivity in W/m.K\n", + "v1 = (26.4*10**-6);\t\t\t#Kinematic vismath.cosity in m**2/s\n", + "Pr = 0.69;\t\t\t#Prantl number\n", + "b = 0.0025;\t\t\t#Coefficient of thermal expansion in 1./K\n", + "a = (38.3*10**-6);\t\t\t#Thermal diffusivity in m**2/s\n", + "Ra = ((9.81*b*L**3*(Ts-Ta))/(v1*a));\t\t\t#Rayleigh number\n", + "Nu = (0.68+((0.67*Ra**0.25)/(1+(0.492/Pr)**(9./16))**(4./9)));\t\t\t#Nussults number\n", + "h = (Nu*k)/L;\t\t\t#Heat transfer coefficient in W/m**2.K\n", + "Q = (h*L*(Ts-Ta));\t\t\t#Rate of heat transfer in W\n", + "Nul = 0.59 * (3.72*10**8)**(1./4)\n", + "\n", + "# Results\n", + "print 'Heat transfer coefficient is %3.3f W/m**2.K Rate of heat transfer is %3.2f W'%(h,Q)\n", + "print \"NuL = %.2f W\"%Nul" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Heat transfer coefficient is 3.990 W/m**2.K Rate of heat transfer is 165.24 W\n", + "NuL = 81.94 W\n" + ] + } + ], + "prompt_number": 4 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 8.4 Page No : 344" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "W = 0.5;\t\t\t#Width of the radiator in m\n", + "L = 1.;\t\t\t#Height of the radiator in m\n", + "Ts = 84.;\t\t\t#Surface temperature in degree C\n", + "Ta = 20.;\t\t\t#Room temperature in degree C\n", + "\n", + "# Calculations\n", + "Tf = (Ts+Ta)/2;\t\t\t#Film temperature in degree C\n", + "k = 0.02815;\t\t\t#Thermal conductivity in W/m.K\n", + "v1 = (18.41*10**-6);\t\t\t#Kinematic viscosity in m**2/s\n", + "Pr = 0.7;\t\t\t#Prantl number\n", + "b = 0.003077;\t\t\t#Coefficient of thermal expansion in 1./K\n", + "Ra = ((9.81*b*L**3*(Ts-Ta)*Pr)/(v1**2));\t\t\t#Rayleigh number\n", + "Nu = (0.825+((0.387*Ra**(1./6))/(1+(0.492/Pr)**(9./16))**(8./27)))**2;\t\t\t#Nussults number\n", + "h = (1170.9*k)/L;\t\t\t#Heat transfer coefficient in W/m**2.K\n", + "Q = (h*W*L*(Ts-Ta));\t\t\t#Convective heat loss in W\n", + "\n", + "# Results\n", + "print 'Convective heat loss from the radiator is %3.2f W'%(Q)\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Convective heat loss from the radiator is 1054.75 W\n" + ] + } + ], + "prompt_number": 9 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 8.5 Page No : 345" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "L = 0.8;\t\t\t#Height of the plate in m\n", + "W = 0.08;\t\t\t#Width of the plate in m\n", + "Ts = 170;\t\t\t#Surafce temperature in degree C\n", + "Tw = 70;\t\t\t#Temperature of water in degree C\n", + "Tf = 130;\t\t\t#Final temperature in degree C\n", + "\n", + "# Calculations\n", + "Tb = (Ts+Tw)/2;\t\t\t#Film temperature in degree C\n", + "p = 960.63;\t\t\t#Density in kg/m**3\n", + "k = 0.68;\t\t\t#Thermal conductivity in W/m.K\n", + "v1 = (0.294*10**-6);\t\t\t#Kinematic viscosity in m**2/s\n", + "b = 0.00075;\t\t\t#Coefficient of thermal expansion in 1./K\n", + "Cp = 4216;\t\t\t#Specific heat in J/kg.K\n", + "a = (1.68*10**-7);\t\t\t#Thermal diffusivity in m**2/s\n", + "Lc = (W/2);\t\t\t#Characteristic length in m\n", + "Ra = ((9.81*b*Lc**3*(Tf-Tw))/(v1*a));\t\t\t#Rayleigh number\n", + "Nu1 = (0.15*Ra**(1./3));\t\t\t#Nussults number\n", + "h1 = (Nu1*k)/Lc;\t\t\t#Heat transfer coefficient at top surface in W/m**2.K \n", + "Nu2 = 0.27*(Ra)**(0.25);\t\t\t#Nusselts number\n", + "h2 = (Nu2*k)/Lc;\t\t\t#Heat transfer coefficient at bottom surface in W/m**2.K\n", + "Q = ((h1+h2)*W*L*(Tf-Tw))/1000;\t\t\t#Rate of heat input to the plate in kW\n", + "\n", + "# Results\n", + "print 'Rate of heat input to the plate necessary to maintain the temperature at %3.0f degree C is %3.2f kW'%(Tf,Q)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Rate of heat input to the plate necessary to maintain the temperature at 130 degree C is 10.85 kW\n" + ] + } + ], + "prompt_number": 6 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 8.6 Page No : 346" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "L = 0.3;\t\t\t#Height of the duct in m\n", + "W = 0.6;\t\t\t#Width of the duct in m\n", + "Ts = 15;\t\t\t#Surface temperature in degree C\n", + "Ta = 25;\t\t\t#Temeprature of air in degree C\n", + "\n", + "# Calculations\n", + "Tb = (Ts+Ta)/2;\t\t\t#Film temperature in degree C\n", + "p = 1.205;\t\t\t#Density in kg/m**3\n", + "k = 0.02593;\t\t\t#Thermal conductivity in W/m.K\n", + "v1 = (15.06*10**-6);\t\t\t#Kinematic viscosity in m**2/s\n", + "b = 0.00341;\t\t\t#Coefficient of thermal expansion in 1./K\n", + "Cp = 1005;\t\t\t#Specific heat in J/kg.K\n", + "Pr = 0.705;\t\t\t#Prantl number\n", + "Ra = ((9.81*b*L**3*(Ta-Ts)*Pr)/(v1**2));\t\t\t#Rayleigh number\n", + "Nux = (0.59*Ra**(0.25));\t\t\t#Nusselts number\n", + "hx = (Nux*k)/L;\t\t\t#Heat transfer coefficient in W/m**2.K\n", + "Lc = (W/2);\t\t\t#Characteristic length in m\n", + "Nu1 = (0.15*Ra**(1./3));\t\t\t#Nussults number\n", + "h1 = (Nu1*k)/Lc;\t\t\t#Heat transfer coefficient at top surface in W/m**2.K \n", + "Nu2 = 0.27*(Ra)**(0.25);\t\t\t#Nusselts number\n", + "h2 = (Nu2*k)/Lc;\t\t\t#Heat transfer coefficient at bottom surface in W/m**2.K\n", + "Q = ((2*hx*L)+(W*(h1+h2)))*(Ta-Ts);\t\t\t#Rate of heat gained per unit length in W/m\n", + "\n", + "# Results\n", + "print 'Rate of heat gained per unit length is %3.2f W/m'%(Q)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Rate of heat gained per unit length is 56.11 W/m\n" + ] + } + ], + "prompt_number": 7 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 8.7 Page No : 348" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "LH = 0.08;\t\t\t#Horizantal length in m\n", + "LV = 0.12;\t\t\t#Vertical length in m\n", + "Ts = 50;\t\t\t#Surface temperature in degree C\n", + "Ta = 0;\t\t\t#Temeprature of air in degree C\n", + "\n", + "# Calculations\n", + "L = (LH*LV)/(LH+LV);\t\t\t#Characteristic length in m\n", + "Tb = (Ts+Ta)/2;\t\t\t#Film temperature in degree C\n", + "p = 0.707;\t\t\t#Density in kg/m**3\n", + "k = 0.0263;\t\t\t#Thermal conductivity in W/m.K\n", + "v1 = (15.89*10**-6);\t\t\t#Kinematic viscosity in m**2/s\n", + "b = (1./300);\t\t\t#Coefficient of thermal expansion in 1./K\n", + "Pr = 0.707;\t\t\t#Prantl number\n", + "Gr = ((9.81*b*L**3*(Ts-Ta))/(v1**2));\t\t\t#Grashof number\n", + "Nu = 0.55*Gr**(0.25);\t\t\t#Nussults number\n", + "h = (Nu*k)/L;\t\t\t#Heat transfer coefficient in W/m**2.K\n", + "\n", + "# Results\n", + "print 'Heat transfer coefficient is %3.2f W/m**2.K'%(h)\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Heat transfer coefficient is 8.77 W/m**2.K\n" + ] + } + ], + "prompt_number": 8 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 8.8 Page No : 349" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "D = 0.2;\t\t\t#Outer diameter of the pipe in m\n", + "Ts = 100;\t\t\t#Surface temperature in degree C\n", + "Ta = 20;\t\t\t#Temperature of air in degree C\n", + "L = 3;\t\t\t#Length of pipe in m\n", + "\n", + "# Calculations\n", + "Tf = (Ts+Ta)/2;\t\t\t#Film temperature in degree C\n", + "k = 0.02896;\t\t\t#Thermal conductivity in W/m.K\n", + "v1 = (18.97*10**-6);\t\t\t#Kinematic viscosity in m**2/s\n", + "b = (1./333);\t\t\t#Coefficient of thermal expansion in 1./K\n", + "Pr = 0.696;\t\t\t#Prantl number\n", + "Gr = ((9.81*b*L**3*(Ts-Ta))/(v1**2));\t\t\t#Grashof number\n", + "Ra = (Gr*Pr);\t\t\t#Rayleigh number\n", + "Nu = (0.1*Ra**(1./3));\t\t\t#Nussults number\n", + "h = (Nu*k)/L;\t\t\t#Heat transfer coefficient in W/m**2.K\n", + "Q = (h*3.14*D*(Ts-Ta));\t\t\t#Rate of heat loss per meter length of pipe in W/m\n", + "\n", + "# Results\n", + "print 'Rate of heat loss per meter length of pipe is %3.2f W/m'%(Q)\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Rate of heat loss per meter length of pipe is 241.24 W/m\n" + ] + } + ], + "prompt_number": 9 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 8.9 Page No : 350" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "D = 0.1;\t\t\t#Outer diamter of the pipe in m\n", + "Ta = 30.;\t\t\t#Ambient temperature of air degree C\n", + "Ts = 170.;\t\t\t#Surface temperature in degree C\n", + "e = 0.9;\t\t\t#Emissivity \n", + "\n", + "# Calculations\n", + "Tb = (Ts+Ta)/2;\t\t\t#Film temperature in degree C\n", + "k = 0.0321;\t\t\t#Thermal conductivity in W/m.K\n", + "v1 = (23.13*10**-6);\t\t\t#Kinematic viscosity in m**2/s\n", + "b = 0.00268;\t\t\t#Coefficient of thermal expansion in 1./K\n", + "Pr = 0.688;\t\t\t#Prantl number\n", + "Ra = ((9.81*b*D**3*(Ts-Ta)*Pr)/(v1**2));\t\t\t#Rayleigh number\n", + "Nu = (0.6+((0.387*Ra**(1./6))/(1+(0.559/Pr)**(9./16))**(8./27)))**2;\t\t\t#Nussults number\n", + "h = (Nu*k)/D;\t\t\t#Heat transfer coefficient in W/m**2.K\n", + "Q = (h*3.1415*D*(Ts-Ta))+(e*3.1415*D*5.67*10**-8*((Ts+273)**4-(Ta+273)**4));\t\t\t#Total heat loss per meter length of pipe in m\n", + "NuD = 0.48*(4.72*10**6)*0.25\n", + "\n", + "# Results\n", + "print 'Total heat loss per meter length of pipe is %3.2f W/m'%(Q)\n", + "print \"NuD = %.2f\"%NuD\n", + "\n", + "# Note : rounding off error.\n", + "# Note : 2nd answer is wrong in book" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Total heat loss per meter length of pipe is 801.20 W/m\n", + "NuD = 566400.00\n" + ] + } + ], + "prompt_number": 16 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 8.10 Page No : 351" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math\n", + "# Variables\n", + "Ta = 25;\t\t\t#Temperature of air in degree C\n", + "Ts = 95;\t\t\t#Surface temperature of wire in degree C\n", + "D = 0.0025;\t\t\t#Diameter of wire in m\n", + "R = 6;\t\t\t#Resistivity in ohm/m\n", + "\n", + "# Calculations\n", + "Tf = (Ts+Ta)/2;\t\t\t#Film temperature in degree C\n", + "k = 0.02896;\t\t\t#Thermal conductivity in W/m.K\n", + "v1 = (18.97*10**-6);\t\t\t#Kinematic viscosity in m**2/s\n", + "b = (1./333);\t\t\t#Coefficient of thermal expansion in 1./K\n", + "Pr = 0.696;\t\t\t#Prantl number\n", + "Gr = ((9.81*b*D**3*(Ts-Ta))/(v1**2));\t\t\t#Grashof number\n", + "Ra = (Gr*Pr);\t\t\t#Rayleigh number\n", + "Nu = (1.18*Ra**(1./8));\t\t\t#Nussults number\n", + "h = (Nu*k)/D;\t\t\t#Heat transfer coefficient in W/m**2.K\n", + "Q = (h*3.14*D*(Ts-Ta));\t\t\t#Rate of heat loss per unit length of wire in W/m\n", + "I = math.sqrt(Q/R);\t\t\t#Maximum current intensity in A\n", + "\n", + "# Results\n", + "print 'Heat transfer coefficient is %3.2f W/m**2.K \\n \\\n", + "Maximum current intensity is %3.2f A'%(h,I)\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Heat transfer coefficient is 22.91 W/m**2.K \n", + " Maximum current intensity is 1.45 A\n" + ] + } + ], + "prompt_number": 11 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 8.11 Page No : 352" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "D = 0.01;\t\t\t#Diameter of spherical steel ball in m\n", + "Ts = 260;\t\t\t#Surface temperature in degree C\n", + "Ta = 20;\t\t\t#Temperature of air in degree C\n", + "\n", + "# Calculations\n", + "Tf = (Ts+Ta)/2;\t\t\t#Film temperature in degree C\n", + "k = 0.0349;\t\t\t#Thermal conductivity in W/m.K\n", + "v1 = (27.8*10**-6);\t\t\t#Kinematic viscosity in m**2/s\n", + "b = (1./413);\t\t\t#Coefficient of thermal expansion in 1./K\n", + "Pr = 0.684;\t\t\t#Prantl number\n", + "Ra = ((9.81*b*D**3*(Ts-20)*Pr)/(v1**2));\t\t\t#Rayleigh number\n", + "Nu = (2+(0.43*Ra**0.25));\t\t\t#Nusuults number\n", + "h = (k*Nu)/D;\t\t\t#Heat transfer coefficient in W/m**2.K\n", + "Q = (h*3.14*D**2*(Ts-Ta));\t\t\t#Rate of heat loss in W\n", + "\n", + "# Results\n", + "print 'Rate of convective heat loss is %3.2f W'%(Q)" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Rate of convective heat loss is 1.48 W\n" + ] + } + ], + "prompt_number": 12 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 8.12 Page No : 353" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "D = 0.1;\t\t\t#Outer diamter of the pipe in m\n", + "Ta = 30;\t\t\t#Ambient temperature of air degree C\n", + "Ts = 170;\t\t\t#Surface temperature in degree C\n", + "e = 0.9;\t\t\t#Emissivity \n", + "\n", + "# Calculations\n", + "h = (1.32*((Ts-Ta)/D)**0.25);\t\t\t#Heat transfer coefficient in W/m**2.K\n", + "q = (h*3.1415*D*(Ts-Ta));\t\t\t#Heat transfer in W/m\n", + "\n", + "# Results\n", + "print 'Heat loss due to free convection is %3.2f W/m'%(q)" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Heat loss due to free convection is 355.12 W/m\n" + ] + } + ], + "prompt_number": 13 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 8.13 Page No : 355" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "L = 0.015;\t\t\t#Thickness of the slot in m\n", + "D = 2;\t\t\t#Dimension of square plate in m\n", + "T1 = 120;\t\t\t#Temperature of plate 1\n", + "T2 = 20;\t\t\t#Temperature of plate 2\n", + "\n", + "# Calculations\n", + "Tf = (T1+T2)/2;\t\t\t#Film temperature in degree C\n", + "k = 0.0295;\t\t\t#Thermal conductivity in W/m.K\n", + "v1 = (2*10**-5);\t\t\t#Kinematic viscosity in m**2/s\n", + "b = (1./343);\t\t\t#Coefficient of thermal expansion in 1./K\n", + "Gr = ((9.81*b*L**3*(T1-T2))/(v1**2));\t\t\t#Grashof number\n", + "ke = (0.064*k*Gr**(1./3)*(D/L)**(-1./9));\t\t\t#Effective thermal conductivity in W/m.K\n", + "Q = (ke*D**2*(T1-T2))/L;\t\t\t#Rate of heat transfer in W\n", + "\n", + "# Results\n", + "print 'Effective thermal conductivity is %3.4f W/m.K Rate of heat transfer is %3.1f W'%(ke,Q)" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Effective thermal conductivity is 0.0317 W/m.K Rate of heat transfer is 844.8 W\n" + ] + } + ], + "prompt_number": 15 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 8.14 Page No : 356" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "d = 0.0254;\t\t\t#Diamath.tance between the plates in m\n", + "Tl = 60;\t\t\t#Temperature of the lower panel n degree C\n", + "Tu = 15.6;\t\t\t#Temperature of the upper panel in degree C\n", + "\n", + "# Calculations\n", + "Tf = (Tl+Tu)/2;\t\t\t#Film temperature in degree C\n", + "p = 1.121;\t\t\t#Density in kg/m**3\n", + "k = 0.0292;\t\t\t#Thermal conductivity in W/m.K\n", + "v1 = (0.171*10**-4);\t\t\t#Kinematic viscosity in m**2/s\n", + "b = (3.22*10**-3);\t\t\t#Coefficient of thermal expansion in 1./K\n", + "Pr = 0.7;\t\t\t#Prantl number\n", + "Gr = ((9.81*b*d**3*(Tl-Tu))/(v1**2));\t\t\t#Grashof number\n", + "Nu = (0.195*Gr**0.25);\t\t\t#Nussults number\n", + "q = (Nu*k*(Tl-Tu))/d;\t\t\t#Heat flux across the gap in W/m**2\n", + "\n", + "# Results\n", + "print 'Free convection heat transfer is %3.1f W/m**2'%(q)" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Free convection heat transfer is 166.7 W/m**2\n" + ] + } + ], + "prompt_number": 16 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 8.15 Page No : 359" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "p = 3;\t\t\t#Pressure of air in atm\n", + "r1 = 0.075;\t\t\t#Radius of first sphere in m\n", + "r2 = 0.1;\t\t\t#Radius of second sphere in m\n", + "L = 0.025;\t\t\t#Distance in m\n", + "T1 = 325;\t\t\t#Temperature of first sphere in K\n", + "T2 = 275;\t\t\t#Temperature of second sphere in K\n", + "R = 287;\t\t\t#Universal gas consmath.tant in J/\n", + "\n", + "# Calculations\n", + "Tf = (T1+T2)/2;\t\t\t#Film temperature in degree C\n", + "d = (p/(R*Tf));\t\t\t#Desnsity in kg/m**3\n", + "k = 0.0263;\t\t\t#Thermal conductivity in W/m.K\n", + "v1 = (5.23*10**-6);\t\t\t#Kinematic viscosity in m**2/s\n", + "b = (1./300);\t\t\t#Coefficient of thermal expansion in 1./K\n", + "Pr = 0.707;\t\t\t#Prantl numbe\n", + "Gr = ((9.81*b*L**3*(T1-T2))/(v1**2));\t\t\t#Grashof number\n", + "Ra = (Gr*Pr);\t\t\t#Rayleigh number\n", + "Ra1 = ((L/((4*r1*r2)**4))*(Ra/((2*r1)**(-7./5)+(2*r2)**(-7./5))**5))**0.25;\t\t\t#Equivalent Rayleigh's number\n", + "ke = (k*0.74*((Pr*Ra1)/(0.861+Pr))**0.25);\t\t \t#Effective thermal conductivity in W/m.K\n", + "Q = (ke*3.14*4*r1*r2*(T1-T2))/L;\t\t \t#Rate of heat loss in W\n", + "\n", + "# Results\n", + "print 'Convection heat transfer rate is %3.2f W'%(Q)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Convection heat transfer rate is 4.92 W\n" + ] + } + ], + "prompt_number": 17 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 8.16 Page No : 362" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "p = 1;\t\t\t#Pressure of air in atm\n", + "Ta = 27;\t\t\t#Temperature of air in degree C\n", + "D = 0.02;\t\t\t#Diamter of the tube in m\n", + "v = 0.3;\t\t\t#Velocity of air in m/s\n", + "Ts = 127;\t\t\t#Surface temperature in degree C\n", + "L = 1;\t\t\t#Length of the tube in m\n", + "\n", + "# Calculations\n", + "k = 0.0262;\t\t\t#Thermal conductivity in W/m.K\n", + "v1 = (1.568*10**-5);\t\t\t#Kinematic viscosity in m**2/s\n", + "Pr = 0.708;\t\t\t#Prantl number\n", + "b = (1./300);\t\t\t#Coefficient of thermal expansion in 1./K\n", + "ub = (1.847*10**-5);\t\t\t#Dynamic viscosity in Ns/m**2\n", + "us = (2.286*10**-5);\t\t\t#Viscosity of wall in Ns/m**2\n", + "Re = (v*D)/v1;\t\t\t#Reynolds number\n", + "Gr = ((9.81*b*D**3*(Ts-Ta))/(v1**2));\t\t\t#Grashof number\n", + "Gz = (Re*Pr*(D/L));\t\t\t#Graetz number\n", + "Nu = (1.75*(ub/us)**0.14*(Gz+(0.012*(Gz*Gr**(1./3))**(4./3)))**(1./3));\t\t\t#Nussults number\n", + "h = (k*Nu)/D;\t\t\t#Heat transfer coefficient in W/m**2.K\n", + "Q = (h*3.14*D*L*(Ts-Ta));\t\t\t#Heat transfer in W\n", + "\n", + "# Results\n", + "print 'Heat transfer in the tube is %3.2f W'%(Q)" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Heat transfer in the tube is 40.86 W\n" + ] + } + ], + "prompt_number": 18 + } + ], + "metadata": {} + } + ] +}
\ No newline at end of file diff --git a/Fundamentals_Of_Engineering_Heat_And_Mass_Transfer/ch9.ipynb b/Fundamentals_Of_Engineering_Heat_And_Mass_Transfer/ch9.ipynb new file mode 100755 index 00000000..bc6026e1 --- /dev/null +++ b/Fundamentals_Of_Engineering_Heat_And_Mass_Transfer/ch9.ipynb @@ -0,0 +1,351 @@ +{ + "metadata": { + "name": "", + "signature": "sha256:20bf663c37cc88094e4d6e0d7e23e0cfc96b3cd4eb305559eda1ce27188b9a4a" + }, + "nbformat": 3, + "nbformat_minor": 0, + "worksheets": [ + { + "cells": [ + { + "cell_type": "heading", + "level": 1, + "metadata": {}, + "source": [ + "Chapter 9 : Thermal radiation basic\n", + "relations" + ] + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 9.1 Page No : 378" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math \n", + "\n", + "# Variables\n", + "T = 5527;\t\t\t#Temperature of black body in degree C\n", + "D = (1.39*10**6);\t\t\t#Diameter of the sun in km\n", + "L = (1.5*10**8);\t\t\t#Distance between the earth and sun in km\n", + "\n", + "# Calculations\n", + "q = (5.67*10**-8*(T+273)**4*D**2)/(4*L**2);\t\t\t#Rate of solar radiation in W/m**2\n", + "\n", + "# Results\n", + "print 'Rate of solar radiation on a plane normal to sun rays is %3.0f W/m**2'%(q)\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Rate of solar radiation on a plane normal to sun rays is 1377 W/m**2\n" + ] + } + ], + "prompt_number": 1 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 9.2 Page No : 383" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "T = (727+273);\t\t\t#Temperature of black body in K\n", + "l1 = 1;\t\t\t#Wavelength in micro meter\n", + "l2 = 5;\t\t\t#Wavelength in micro meter\n", + "F1 = 0.0003;\t\t\t#From Table 9.2 on page no. 385\n", + "F2 = 0.6337;\t\t\t#From Table 9.2 on page no. 385\n", + "\n", + "# Calculations\n", + "a = (5.67*10**-8*T**4)/1000;\t\t\t#Heat transfer in kW/m**2\n", + "F = (F2-F1)*a;\t\t\t#Fraction of thermal radiation emitted by the surface in kW/m**2\n", + "\n", + "# Results\n", + "print 'Fraction of thermal radiation emitted by the surface is %3.1f kW/m**2'%(F)\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Fraction of thermal radiation emitted by the surface is 35.9 kW/m**2\n" + ] + } + ], + "prompt_number": 2 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 9.3 Page No : 384" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "t = 0.8;\t\t\t#Transmittivity of glass in the region except in the wave length region [0.4,3]\n", + "T = 5555;\t\t\t#Temperature of black body in K\n", + "\n", + "# Calculations\n", + "ao = 0;\t\t\t#a0 in micro K\n", + "a1 = (0.4*T);\t\t\t#a1 for the wavelength 0.4 micro meter in micro K\n", + "a2 = (3*T);\t\t\t#a1 for the wavelength 3 micro meter in micro K\n", + "F0 = 0;\t\t\t#From Table 9.2 on page no.385\n", + "F1 = 0.10503;\t\t\t#From Table 9.2 on page no.385\n", + "F2 = 0.97644;\t\t\t#From Table 9.2 on page no.385\n", + "t1 = t*(F2-F1);\t\t\t#Average hemispherical transmittivity of glass \n", + "\n", + "# Results\n", + "print 'Average hemispherical transmittivity of glass is %3.2f'%(t1)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Average hemispherical transmittivity of glass is 0.70\n" + ] + } + ], + "prompt_number": 3 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 9.4 Page No : 386" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "l = 0.5;\t\t\t#Wavelength at maximum intensity of radiation in micro meter\n", + "C3 = 0.289*10**-2 #mK\n", + "\n", + "# Calculations\n", + "T = C3/(l*10**-6);\t\t\t#Temperature according to Wien's print lacement law in degree C\n", + "E = (5.67*10**-8*T**4)/10**6;\t\t\t#Emissive power umath.sing Stefan-Boltzmann law in MW/m**2\n", + "\n", + "# Results\n", + "print 'Surface temperature is %3.0f K Emissive power is %3.1f MW/m**2'%(T,E)\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Surface temperature is 5780 K Emissive power is 63.3 MW/m**2\n" + ] + } + ], + "prompt_number": 1 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 9.5 Page No : 389" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "Ts = (827+273);\t\t\t#Surface temperature in degree C\n", + "E = (1.37*10**10);\t\t\t#Emmisive power in W/m**3\n", + "\n", + "# Calculations\n", + "Eblmax = (1.307*10**-5*Ts**5);\t\t\t#Maximum emissive power in W/m**3\n", + "e = (E/Eblmax);\t\t\t#Emissivity of the body \n", + "lmax = ((0.289*10**-2)/Ts)/10**-6;\t\t\t#Wavelength correspoing to the maximum spectral intensity of radiation in micro meter\n", + "\n", + "# Results\n", + "print 'Wavelength corresponding to the maximum spectral intensity of radiation is %3.2f micro meter'%(lmax)\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Wavelength corresponding to the maximum spectral intensity of radiation is 2.63 micro meter\n" + ] + } + ], + "prompt_number": 6 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 9.6 Page No : 389" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math\n", + "# Variables\n", + "T = (1400+273);\t\t\t#Temperature of the body in K\n", + "l = 0.65;\t\t\t#Wavelength in micro meter\n", + "e = 0.6;\t\t\t#Emissivity\n", + "\n", + "# Calculations\n", + "T = (1./((1./T)-((l*10**-6*math.log(1./e))/(1.439*10**-2))));\t\t\t#Temperature of the body in K\n", + "Tb = (T-273);\t\t\t#Temperature of the body in degree C\n", + "\n", + "# Results\n", + "print 'Temperature of the body is %3.0f degree C'%(Tb)\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Temperature of the body is 1467 degree C\n" + ] + } + ], + "prompt_number": 7 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 9.7 Page No : 391" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "Ts = (37+273);\t\t\t#Temperature of metallic bar in K\n", + "T = 1100;\t\t\t#Interior temperature in K\n", + "a = 0.52;\t\t\t#Absorptivity at 1100 K\n", + "e = 0.8;\t\t\t#Emissivity at 310 K\n", + "\n", + "# Calculations\n", + "Q = (a*5.67*10**-8*T**4)/1000;\t\t\t#Rate of absorption in kW/m**2\n", + "E = (e*5.67*10**-8*Ts**4)/1000;\t\t\t#Rate of emission in kW/m**2\n", + "\n", + "# Results\n", + "print 'Rate of absorption is %3.2f kW/m**2 \\n \\\n", + "Rate of emission is %3.2f kW/m**2'%(Q,E)\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Rate of absorption is 43.17 kW/m**2 \n", + " Rate of emission is 0.42 kW/m**2\n" + ] + } + ], + "prompt_number": 2 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 9.8 Page No : 391" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "e1 = 0.3\t\t\t#Emissivity of glass upto 3 micro meter\n", + "e2 = 0.9;\t\t\t#Emissivity of glass above 3 micro meter\n", + "t = 0.8;\t\t\t#Transmittivity of glass in the region except in the wave length region [0.4,3]\n", + "\n", + "# Calculations\n", + "E = (5.67*10**-8*5780**4)/10**6;\t\t\t#Emissive power in MW/m**2\n", + "F1 = 0.10503;\t\t\t#From Table 9.2 on page no.385\n", + "F2 = 0.97644;\t\t\t#From Table 9.2 on page no.385\n", + "I = (E*10**6*(F2-F1))/10**6;\t\t\t#Total incident radiation in MW/m**2\n", + "T = (t*I);\t\t\t#Total radiation transmitted in MW/m**2\n", + "t1 = (e1*I);\t\t\t#Absorbed radiation in MW/m**2 in wavelength [0.4,3] micro meter\n", + "t2 = (e1*E*F1);\t\t\t#Absorbed radiation in MW/m**2 in wavelength not in the range [0.4,3] micro meter\n", + "t3 = (e2*(1-F2)*E);\t\t\t#Absorbed radiation in MW/m**2 in wavelength greater than 3 micro meter\n", + "R = (t1+t2+t3);\t\t\t#Total radiation absorbed in MW/m**2\n", + "\n", + "# Results\n", + "print 'Total radiation transmitted is %3.2f MW/m**2 \\n \\\n", + "Total radiation absorbed is %3.2f MW/m**2'%(T,R)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Total radiation transmitted is 44.12 MW/m**2 \n", + " Total radiation absorbed is 19.88 MW/m**2\n" + ] + } + ], + "prompt_number": 9 + } + ], + "metadata": {} + } + ] +}
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