{ "metadata": { "name": "EHP-3" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": "Internal Combustion Engines" }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": "Example 3.1 , Page 131" }, { "cell_type": "code", "collapsed": false, "input": "# Initialization of Variable\nfrom math import pi\nfrom math import atan\nfrom numpy import *\nre=6.0\nk=1.4\n\n#calculations\nnt=1-1/re**(k-1)\nntt=nt*100 #efficiency\n\n#results\nprint \"Thermal efficiency in percent\",round(ntt,3)", "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": "Thermal efficiency in percent 51.164\n" } ], "prompt_number": 16 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": "Example 3.2,Page 132" }, { "cell_type": "code", "collapsed": false, "input": "# Initialization of Variable\nfrom math import pi\nfrom math import atan\nfrom numpy import *\nd=3.25 #in\nstroke=4.0 #in\nv=6.0 #cu in\n\n#calculations\nDp=d**2 *pi*stroke/4\nr=(Dp+v)/v #compression ratio\n\n#results\nprint \"Compression ratio \",round(r,3)", "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": "Compression ratio 6.531\n" } ], "prompt_number": 1 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": "Example 3.3,Page 133" }, { "cell_type": "code", "collapsed": false, "input": "# Initialization of Variable\nfrom math import pi\nfrom math import atan\nfrom numpy import *\nper=20.0\nDp=100.0\n\n#calculations\nr=Dp/per +1\n\n#results\nprint \"Compression ratio \",round(r,3)", "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": "Compression ratio 6.0\n" } ], "prompt_number": 18 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": "Example 3.4,Page 136" }, { "cell_type": "code", "collapsed": false, "input": "# Initialization of Variable\nfrom math import pi\nfrom math import atan\nfrom numpy import *\nr=16.0\nrc=4.0\nk=1.4\n\n#calculations\netat=1-1/r**(k-1) *((rc**k -1)/(k*(rc-1)))\neta=etat*100; #efficiency\n\n#results\nprint \"Thermal efficiency in percent\",round(eta,3)\nprint \"The answer is a bit different due to rounding off error in the textbook\"", "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": "Thermal efficiency in percent 53.154\nThe answer is a bit different due to rounding off error in the textbook\n" } ], "prompt_number": 19 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": "Example 3.5,Page 142" }, { "cell_type": "code", "collapsed": false, "input": "# Initialization of Variable\nfrom math import pi\nfrom math import atan\nfrom numpy import *\nF=200 #lb\narea=1.65 #sq. in\nlength=3.5 #in\n\n#calculations\nord=area/length\nmep=ord*F\n\n#results\nprint \"MEP of an engine in psi\",round(mep,3)", "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": "MEP of an engine in psi 94.286\n" } ], "prompt_number": 2 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": "Example 3.6,Page 143" }, { "cell_type": "code", "collapsed": false, "input": "# Initialization of Variable\nfrom math import pi\nfrom math import atan\nfrom numpy import *\nPi=90 #psi\nL=5.0/12.0 #ft\nr=5.0 #in\nx=1.5 #ft\nrpm=1500.0 #rpm\n\n#calculations\nA=pi*x*x\nN=rpm*4/2\nIhp=Pi*L*A*N/33000.0\n\n#results\nprint \"IHP of cylinder \",round(Ihp,3)", "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": "IHP of cylinder 24.097\n" } ], "prompt_number": 1 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": "Example 3.7,Page 144" }, { "cell_type": "code", "collapsed": false, "input": "# Initialization of Variable\nfrom math import pi\nfrom math import atan\nfrom numpy import *\nr=4.0 #ft\nn=300.0 #rpm\nF=60.0 #lb\n\n#calculations\nBhp=2*pi*r*F*n/33000\n\n#results\nprint \"Bhp of the engine \",round(Bhp,3)", "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": "Bhp of the engine 13.709\n" } ], "prompt_number": 22 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": "Example 3.8,Page 147" }, { "cell_type": "code", "collapsed": false, "input": "# Initialization of Variable\nfrom math import pi\nfrom math import atan\nfrom numpy import *\nC=1.0/4000.0\nF=125.0 #lb\nn=3500 #rpm\n\n#calculations\nBhp=F*n*C\n\n#results\nprint \"Bhp of the engine \",round(Bhp,3)", "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": "Bhp of the engine 109.375\n" } ], "prompt_number": 23 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": "Example 3.9,Page 151" }, { "cell_type": "code", "collapsed": false, "input": "# Initialization of Variable\nfrom math import pi\nfrom math import atan\nfrom numpy import *\nr=1.75 #ft\nF1=72.0 #lb\nF2=24.0 #lb\nn=500.0 #rpm\nm=1.8 #lb\nmi=15.0 #min\nQh=20000.0 #Btu/lb\n\n#calculations\nBhp=2*pi*r*F1*n/33000.0\nFhp=2*pi*r*F2*n/33000.0\nIhp=Bhp+Fhp\nFc=m*60/mi\nBsfc=Fc/Bhp\nIsfc=Fc/Ihp\netam=Bhp/Ihp *100\netabt=Bhp*2545/(Fc*Qh)\netait=Ihp*2545/(Fc*Qh)\n\n#results\nprint \"Thermal efficiency in percent\",round(etam,3)\nprint \" Brake thermal effficiency in percent\",round(etabt*100,3)\nprint \" Indicated thermal effficiency in percent\",round(etait*100,3)", "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": "Thermal efficiency in percent 75.0\n Brake thermal effficiency in percent 21.2\n Indicated thermal effficiency in percent 28.266\n" } ], "prompt_number": 24 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": "Example 3.10,Page 191" }, { "cell_type": "code", "collapsed": false, "input": "# Initialization of Variable\nfrom math import pi\nfrom math import atan\nfrom numpy import *\nbore=3.0 #in\nstroke=4.0 #in\nrpm=3000.0 #rpm\nair=110.0 #cu ft per min\n\n#calculations\npdv=bore*bore*pi*stroke*2*bore/4\npde=pdv*rpm /2\nreq=air*1728\neff=req/pde *100; #efficiency\n\n#results\nprint \"Volumetric efficiency in percent\",round(eff,3)", "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": "Volumetric efficiency in percent 74.697\n" } ], "prompt_number": 3 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": "Example 3.11, Page 244" }, { "cell_type": "code", "collapsed": false, "input": "# Initialization of Variable\nfrom math import pi\nfrom math import atan\nfrom numpy import *\nx1=11.5 # CO2\nx2=4.1 #CO\nx3=0.4 #O2\nx4=2.3 # H2\nx5=0.2 #CH4\nx6=81.5 #N2\nyc=0.842 #lb of C \nyh=0.158 #lb of H2\nbasis=1\nbhp=100\nburn=8.9 #gal/hr\nsg=0.731\nQh=20750.0 #Btu/lbm\nrate=66.0 #gpm\nex=1100.0 #F\nair=70.0 #F\ncp=0.254\nh2=4330.0 #btu/lb\nh4=62000.0 #btu/lb \nh5=23700.0 #btu/lb\n\n#calculations\nc1=x1*44 #mass CO2\nc2=x2*28 #mass CO\nc3=x3*32 #mass O2\nc4=x4*2 #mass H2\nc5=x5*16 #mass CH4\nc6=x6*28 #mass N2\nsumm=c1+c2+c3+c4+c5+c6\ncarbon=x1*12 + x2*12+x5*12\nhydrogen=x4*2+x5*4\nlbdrygas=summ/carbon *yc\nlbfuel=carbon/yc\nlbH=lbfuel*yh\nlbH2=lbH-hydrogen\nlb3=lbH2*9\nlbwater=lb3/lbfuel\nlbair=lbdrygas+lbwater-basis\nbsfc=burn*sg*8.33/bhp\nfuelmin=bsfc*bhp/60\nenergy=2545/bsfc\nper1=energy/Qh #energy supplied\nEc=rate*8.33*10\nEclb=Ec/fuelmin\nper2=Eclb/Qh #energy absorbed\ndryloss=(ex-air)*cp*lbdrygas\nper3=dryloss/Qh #energy lost\nhv2=h2*c2/lbfuel\nhv4=h4*c4/lbfuel\nhv5=h5*c5/lbfuel\nhv=hv2+hv4+hv5\nper4=hv/Qh #energy supplied\neh2=lbwater*(1066+0.5*ex-air)\nper5=eh2/Qh #energy supplied\nrad=1017 \nper6=rad/Qh; #energy supplied\n\n#results\nprint \"Air supplied per lb of fuel in lb air per lb fuel\",round(lbair,3)\nprint \"Percentage of energy supplied utilized in Btu in percent\",round(per1*100,3)\nprint \"Percentage of energy absorbed by coolant in percent\",round(per2*100,3)\nprint \"Energy lost in sensible heat in percent\",round(per3*100,3)\nprint \"Energy supplied in combustiles in exhaust in percent\",round(per4*100,3)\nprint \"Energy supplied in water formed by combustion in percent\",round(per5*100,3)\nprint \"Energy supplied unaccounted for in percent\",round(per6*100,3)", "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": "Air supplied per lb of fuel in lb air per lb fuel 13.189\nPercentage of energy supplied utilized in Btu in percent 22.632\nPercentage of energy absorbed by coolant in percent 29.334\nEnergy lost in sensible heat in percent 16.369\nEnergy supplied in combustiles in exhaust in percent 18.366\nEnergy supplied in water formed by combustion in percent 8.987\nEnergy supplied unaccounted for in percent 4.901\n" } ], "prompt_number": 27 } ], "metadata": {} } ] }