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{
"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": {}
}
]
}
|
