{ "metadata": { "name": "", "signature": "sha256:d0883c349e6026c1b16a5b0a707e34ddc2310403ffaeb85c40a328facdc14025" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Two dimensional, Steady State Conduction" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 4.1 Page 211 " ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "import math\n", "d = .005; \t\t\t\t\t\t\t\t\t\t#[m] Diameter of wire\n", "k = .35; \t\t\t\t\t\t\t\t\t\t#[W/m.K] Thermal Conductivity\n", "h = 15; \t\t\t\t\t\t\t\t\t\t#[W/m^2.K] Total coeff with Convection n Radiation\n", "#calculations\n", "\n", "rcr = k/h; \t\t\t\t\t\t\t\t\t\t# [m] critical insulation radius\n", "tcr = rcr - d/2.; \t\t\t\t\t\t\t\t\t\t# [m] critical insulation Thickness\n", "\n", "Rtcond = 2.302*math.log10(rcr/(d/2.))/(2*math.pi*k); #[K/W] Thermal resistance \n", "\n", "#Using Table 4.1 Case 7\n", "z = .5*tcr;\n", "D=2*rcr;\n", "Rtcond2D = (math.acosh((D*D + d*d - 4*z*z)/(2*D*d)))/(2*math.pi*k);\n", "#results\n", "\n", "print '%s %.2f %s' %(\"\\n\\n The reduction in thermal resistance of the insulation is\", Rtcond-Rtcond2D,\" K/W \");\n", "#END" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "\n", "\n", " The reduction in thermal resistance of the insulation is 0.10 K/W \n" ] } ], "prompt_number": 1 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 4.3 Page 224" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "import math\n", "import numpy\n", "from numpy import linalg\n", "Ts = 500.; \t#[K] Temp of surface\n", "Tsurr = 300.; \t#[K] Temp of surrounding Air\n", "h = 10.; \t#[W/m^2.K] Heat Convection soefficient\n", "#Support Column\n", "delx = .25; \t#[m]\n", "dely = .25; \t#[m]\n", "k = 1.; \t#[W/m.K] From Table A.3, Fireclay Brick at T = 478K\n", "#calculations\n", "\n", "#Applying Eqn 4.42 and 4.48\n", "A = numpy.array([[-4, 1, 1, 0, 0, 0, 0, 0],\n", "\t\t[2, -4, 0, 1, 0, 0, 0, 0],\n", "\t\t[1, 0, -4, 1, 1, 0, 0, 0],\n", "\t\t[0, 1, 2, -4, 0, 1, 0, 0],\n", "\t\t[0,0, 1, 0, -4, 1, 1, 0],\n", "\t\t[0, 0, 0, 1, 2, -4, 0, 1],\n", "\t\t[0, 0, 0, 0, 2, 0, -9, 1],\n", "\t\t[0, 0, 0, 0, 0, 2, 2, -9]]);\n", " \n", "C = numpy.array([[-1000], [-500], [-500], [0], [-500], [0], [-2000], [-1500]]);\n", "\n", "T = numpy.linalg.solve (A,C);\n", "#results\n", "\n", "print '%s' %(\"\\n Temp Distribution in K = \");\n", "print (T);\n", "\n", "q = 2*h*((delx/2.)*(Ts-Tsurr)+delx*(T[6]-Tsurr)+delx*(T[7]-Tsurr)/2.);\n", "print '%s %.2f %s' %(\"\\n\\n Heat rate from column to the airstream\",q,\" W/m \");\n", "#END" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "\n", " Temp Distribution in K = \n", "[[ 489.30472333]\n", " [ 485.15381783]\n", " [ 472.06507549]\n", " [ 462.00582466]\n", " [ 436.94975396]\n", " [ 418.73932983]\n", " [ 356.99461052]\n", " [ 339.05198674]]" ] }, { "output_type": "stream", "stream": "stdout", "text": [ "\n", "\n", "\n", " Heat rate from column to the airstream 882.60 W/m \n" ] } ], "prompt_number": 2 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 4.4 Page 230" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "import math\n", "import numpy\n", "from numpy import linalg\n", "#Operating Conditions\n", "\n", "ho = 1000; #[W/m^2.K] Heat Convection coefficient\n", "hi = 200; #[W/m^2.K] Heat Convection coefficient\n", "Ti = 400; #[K] Temp of Air\n", "Tg = 1700; #[K] Temp of Gas\n", "h = 10 ; #[W/m^2.K] Heat Convection coefficient\n", "\n", "A = 2*6*math.pow(10,-6) ;#[m^2] Cross section of each Channel\n", "x = .004 ; #[m] Spacing between joints\n", "t = .006; #[m] Thickness\n", "k = 25; #[W/m.K] Thermal Conductivity of Blade\n", "delx = .001 ; #[m]\n", "dely = .001 ; #[m]\n", "#calculations and results\n", "\n", "#Applying Eqn 4.42 and 4.48\n", "A = numpy.array([[-(2+ho*delx/k), 1, 0,0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],\n", " [1,-2*(2+ho*delx/k),1,0,0,0,0,2,0,0,0,0,0,0,0,0,0,0,0,0,0],\n", " [0,1,-2*(2+ho*delx/k),1,0,0,0,0,2,0,0,0,0,0,0,0,0,0,0,0,0],\n", " [0,0,1,-2*(2+ho*delx/k),1,0,0,0,0,2,0,0,0,0,0,0,0,0,0,0,0],\n", " [0,0,0,1,-2*(2+ho*delx/k),1,0,0,0,0,2,0,0,0,0,0,0,0,0,0,0],\n", " [0,0,0,0,1,-(2+ho*delx/k),0,0,0,0,0,1,0,0,0,0,0,0,0,0,0],\n", " [1,0,0,0,0,0,-4,2,0,0,0,0,1,0,0,0,0,0,0,0,0],\n", " [0,1,0,0,0,0,1,-4,1,0,0,0,0,1,0,0,0,0,0,0,0],\n", " [0,0,1,0,0,0,0,1,-4,1,0,0,0,0,1,0,0,0,0,0,0],\n", " [0,0,0,1,0,0,0,0,1,-4,1,0,0,0,0,1,0,0,0,0,0],\n", " [0,0,0,0,1,0,0,0,0,1,-4,1,0,0,0,0,1,0,0,0,0],\n", " [0,0,0,0,0,1,0,0,0,0,2,-4,0,0,0,0,0,1,0,0,0],\n", " [0,0,0,0,0,0,1,0,0,0,0,0,-4,2,0,0,0,0,1,0,0],\n", " [0,0,0,0,0,0,0,1,0,0,0,0,1,-4,1,0,0,0,0,1,0],\n", " [0,0,0,0,0,0,0,0,2,0,0,0,0,2,-2*(3+hi*delx/k),1,0,0,0,0,1],\n", " [0,0,0,0,0,0,0,0,0,2,0,0,0,0,1,-2*(2+hi*delx/k),1,0,0,0,0],\n", " [0,0,0,0,0,0,0,0,0,0,2,0,0,0,0,1,-2*(2+hi*delx/k),1,0,0,0],\n", " [0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,1,-(2+hi*delx/k),0,0,0],\n", " [0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,-2,1,0],\n", " [0,0,0,0,0,0,0,0,0,0,0,0,0,2,0,0,0,0,1,-4,1],\n", " [0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,1,-(2+hi*delx/k)]]);\n", " \n", "C = numpy.array([[-ho*delx*Tg/k], \n", " [-2*ho*delx*Tg/k],\n", " [-2*ho*delx*Tg/k],\n", " [-2*ho*delx*Tg/k],\n", " [-2*ho*delx*Tg/k],\n", " [-ho*delx*Tg/k],\n", " [0],\n", " [0],\n", " [0],\n", " [0],\n", " [0],\n", " [0],\n", " [0],\n", " [0],\n", " [-2*hi*delx*Ti/k],\n", " [-2*hi*delx*Ti/k],\n", " [-2*hi*delx*Ti/k],\n", " [-hi*delx*Ti/k],\n", " [0],\n", " [0],\n", " [-hi*delx*Ti/k]]);\n", "\n", "T = numpy.linalg.solve (A,C);\n", "print '%s' %(\"\\n Temp Distribution in K = \");\n", "print (T);\n", "q = 4*ho*((delx/2.)*(Tg-T[0])+delx*(Tg-T[1])+delx*(Tg-T[2])+ delx*(Tg-T[3])+delx*(Tg-T[4])+delx*(Tg-T[5])/2.);\n", "print '%s %.1f %s' %(\"\\n\\n Heat rate Transfer = \" ,q,\"W/m \");\n", "#END" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "\n", " Temp Distribution in K = \n", "[[ 1525.95413813]\n", " [ 1525.27944565]\n", " [ 1523.59609075]\n", " [ 1521.93574674]\n", " [ 1520.83066847]\n", " [ 1520.45069026]\n", " [ 1519.66699612]\n", " [ 1518.7949547 ]\n", " [ 1516.52842892]\n", " [ 1514.53554374]\n", " [ 1513.30134519]\n", " [ 1512.88873965]\n", " [ 1515.12393697]\n", " [ 1513.70494809]\n", " [ 1509.18712651]\n", " [ 1506.37665411]\n", " [ 1504.9504289 ]\n", " [ 1504.50157796]\n", " [ 1513.41885557]\n", " [ 1511.71377418]\n", " [ 1506.02634497]]\n", "\n", "\n", " Heat rate Transfer = 3540.6 W/m \n" ] } ], "prompt_number": 3 } ], "metadata": {} } ] }