{ "metadata": { "name": "" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter 9 : Computers and their application" ] }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "example 9.1 page number 384" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "import math \n", "D = 38.*10**-3; #in m\n", "U = 1. #in m/s\n", "density = 998. #in kg/cubic m\n", "viscosity = 8.*10**-4 #in Pa-s\n", "DC = 1. #in m\n", "N = 10.\n", "e = 4.*10**-6; #in m\n", "\n", "Re = (density*U*D)/viscosity;\n", "print \"Reynolds number = %f\"%(Re)\n", "\n", "f = (4*math.log10((e/D)/3.7+(6.81/Re)**0.9))**-2;\n", "print \"friction factor = %f\"%(f);\n", "\n", "L = 3.14*DC*N;\n", "\n", "delta_Pstr = (2*f*U*density*L)/D;\n", "print \"pressure drop through straight pipe = %f Pa\"%(delta_Pstr)\n", "\n", "S = 1+3.54*(D/DC);\n", "print \"correction factor = %f\"%(S)\n", "\n", "delta_P = S*delta_Pstr\n", "print \"pressure drop of coil = %f Pa\"%(delta_P)\n", "\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Reynolds number = 47405.000000\n", "friction factor = 0.005330\n", "pressure drop through straight pipe = 8791.184173 Pa\n", "correction factor = 1.134520\n", "pressure drop of coil = 9973.774268 Pa\n" ] } ], "prompt_number": 1 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "example 9.2 page number 384\n" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "import math \n", "U = 0.5 #in m/s\n", "N = 19.;\n", "DT = 0.026 #in m\n", "L = 2.7 #in m\n", "DS = 0.2 #in m\n", "e = 0.0002 #in m\n", "density = 836. #in kg/cu m\n", "viscosity = 0.00032 #in Pa s\n", "Pr = 6.5;\n", "Prw = 7.6;\n", "\n", "HYDIA = (DS**2-N*DT**2)/(DS+N*DT);\n", "Re = HYDIA*U*density/viscosity;\n", "print \"Reynolds number = %f\"%(Re)\n", "\n", "f = (4*math.log10((e/HYDIA)/3.7+(6.81/Re)**0.9))**-2;\n", "print \"friction factor = %f\"%(f);\n", "\n", "L = 3.14*DT*N;\n", "\n", "delta_Pstr = (2*f*U*density*L)/HYDIA;\n", "print \"pressure drop through straight pipe = %f Pa\"%(delta_Pstr)\n", "\n", "S = (Prw/Pr)**0.33;\n", "print \"correction factor = %f\"%(S)\n", "\n", "delta_P = S*delta_Pstr\n", "print \"pressure drop of coil = %f Pa\"%(delta_P)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Reynolds number = 51113.148415\n", "friction factor = 0.008158\n", "pressure drop through straight pipe = 270.362537 Pa\n", "correction factor = 1.052948\n", "pressure drop of coil = 284.677794 Pa\n" ] } ], "prompt_number": 2 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "example 9.3 page number 385\n" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "MH = 10. #in kg/s\n", "MC = 12.5 #in kg/s\n", "CPH = 4.2 #in kJ/kg\n", "CPC = 4.2 #in kJ/kg\n", "THI = 353. #in K\n", "THO = 333. #in K\n", "TCI = 300. #in K\n", "U = 1.8 #in kW/sq m K\n", "\n", "Q = MH*CPH*(THI-THO);\n", "print \"heat load = %f J\"%(Q)\n", "\n", "TCO = Q/(MC*CPC)+TCI;\n", "print \"cold fluid outlet temperature = %f K\"%(TCO)\n", "\n", "\n", "DT1 = THI-TCO;\n", "DT2 = THO-TCO;\n", "\n", "LMTD = (DT1-DT2)/math.log(DT1/DT2);\n", "\n", "A = Q/(U*LMTD);\n", "print \"for co current flow area = %f sq m\"%(A);\n", "\n", "\n", "DT1 = THI-TCO;\n", "DT2 = THO-TCI;\n", "\n", "LMTD = (DT1-DT2)/math.log(DT1/DT2);\n", "\n", "A = Q/(U*LMTD);\n", "print \"for counter current flow area = %f sq m\"%(A);\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "heat load = 840.000000 J\n", "cold fluid outlet temperature = 316.000000 K\n", "for co current flow area = 18.146440 sq m\n", "for counter current flow area = 13.347874 sq m\n" ] } ], "prompt_number": 3 }, { "cell_type": "code", "collapsed": false, "input": [], "language": "python", "metadata": {}, "outputs": [] } ], "metadata": {} } ] }