{ "metadata": { "name": "", "signature": "sha256:7a4f335b4806f25fef0bf94c3a05e4c422a4dc1cb839f62bebcb4060f38f97a2" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "CHAPTER 8: INTERNAL COMBUSTION ENGINES: VARIABLE SPECIFIC HEATS" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 8.1 Page 128" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#initialisation of variable\n", "from math import pi,sqrt,acos,asin,atan,cos,sin,tan\n", "b=6#in\n", "b1=9.0#in\n", "r1=4.0#ratio\n", "r2=1.0#ratio\n", "p=50#lb/in^2\n", "s=300#r p m\n", "e=30#per cent\n", "v=260#C.H.U\n", "a=1.41\n", "h=0.30#in\n", "g=33000#in\n", "g1=1400#in\n", "A=1-(r2/r1)**0.41#lb/in^2\n", "\n", "#CALCULATIONS\n", "I=(p*pi*36/4*9/12*s/2)*1/g#ft^3\n", "X=(I*g)/(g1*v*h)#ft^3\n", "C=X*60/I#ft^3\n", "R=h/A*100#per cent\n", "\n", "#RESULTS\n", "print\"The fuel consumption in ft^3/h p hr and the efficiency relative to the air standard cycle is\",round(R,3),\"%\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The fuel consumption in ft^3/h p hr and the efficiency relative to the air standard cycle is 69.195 %\n" ] } ], "prompt_number": 2 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 8.3 Page 129" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#initialisation of variable\n", "from math import pi,sqrt,acos,asin,atan,cos,sin,tan\n", "h=200.0#r p m\n", "h1=50.0#i h p\n", "P4=33.4#lb/in^2\n", "W=9000.0#ft lb\n", "x=33000.0#ft.lb\n", "p=1728.0#ft/lb\n", "\n", "#CALCULATIONS\n", "w=h1*x/100.0#ft lb\n", "T=w/W#ft^3\n", "V =13.0/14.0*T#ft^3\n", "D=((V*p*8)/(3*pi))**(1.0/3.0)#in\n", "\n", "#RESULTS\n", "print\"The diameter of the cylinder of a single acting and swept volume is\",round(D,3),\"in\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The diameter of the cylinder of a single acting and swept volume is 13.567 in\n" ] } ], "prompt_number": 5 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 8.6 Page 132" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#initialisation of variable\n", "from math import pi,sqrt,acos,asin,atan,cos,sin,tan\n", "h=12#in\n", "h1=18#in\n", "v=19000#B.Th.U/lb\n", "T=12600#lb/in^2\n", "m=90#lb/in^2\n", "w=120#gal\n", "t1=140#F\n", "t2=60#F\n", "t3=570#F\n", "Cv=0.24#ft/lb\n", "q=810#ft/lb\n", "n=16.9#lb\n", "\n", "#CALCULATIONS\n", "H=(n/t2*v)#B.Th.U\n", "H1=(m*pi*(144/4)*(h1/h)*(T/t2))/(778*2)#B.TH.U/min\n", "H2=1750#B.Th.U\n", "H3=(H1-H2)#B.Th.U\n", "W=(w*10/t2)*(t1-t2)#B,Th.U\n", "G=((q+n)/(t2))*(t3-t2)*Cv#B.TH.U\n", "\n", "#RESULTS\n", "print\"The heat balance showing heat quantities received and the discharged per min is\",round(G,3),\"B.TH.u\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The heat balance showing heat quantities received and the discharged per min is 1686.876 B.TH.u\n" ] } ], "prompt_number": 6 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 8.8 Page 133" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#initialisation of variable\n", "from math import pi,sqrt,acos,asin,atan,cos,sin,tan\n", "v=12.5 #i.p.h\n", "p1=8.25#in\n", "p2=12.0#in\n", "t=110.0#per min\n", "g1=280.0#C.H.U/ft^3\n", "g2=215.0#ft^3\n", "V=25.0#percent\n", "e=0.875#in\n", "T=33000.0#in\n", "v1=0.4170#ft^3\n", "\n", "#CALCULATIONS\n", "M=(T*v)/((pi*(p1)**2.0)/(4.0)*(p2/p2)*(t))#lb.in^2\n", "V1=pi*(p1)**2.0/4.0*p2/1728.0*e#ft^3\n", "V2=(pi*(p1)**2.0*p2)/(4.0*4.0*1728.0)#ft^3\n", "G=(g2/60.0*1.0/t)#ft^3\n", "T1=G*g1#C.H.U\n", "T2=(T1/v1)#C.H.U\n", "F=(M/T2)#C.H.U\n", "\n", "#RESULTS\n", "print\"The value of the Tookey factor for gas engine is\",round(F,3),\"C.H.U\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The value of the Tookey factor for gas engine is 3.207 C.H.U\n" ] } ], "prompt_number": 8 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 8.10 Page 135 " ] }, { "cell_type": "code", "collapsed": false, "input": [ "#initialisation of variable\n", "from math import pi,sqrt,acos,asin,atan,cos,sin,tan\n", "p1=140#lb/in^2\n", "p2=6.6#lb/in^2\n", "v1=122#r.p.m\n", "v2=1250#b.h.p\n", "t=1425#i.h.p\n", "p3=77.8#lb/in^2\n", "h=0.356#lb\n", "v=10000#C.H.U/lb\n", "h2=2400#lb\n", "q=33000#in\n", "j=1400#in\n", "\n", "#CALCULATIONS\n", "t=(v2*q*60)/(j*h*v2*v)*100#percent\n", "V=(p3*144*v1)/(q*2)#V\n", "V1=(p2*144*v1)/q#V\n", "T=24.16#V\n", "V2=t/T#ft^3\n", "I=V*V2#ft^3\n", "I1=V1*V2#ft^3\n", "H=24904#C/.H.U//mim\n", "T=(I*q*60)/(j*h*v2*v)*100#percent\n", "T1=(I1*q)/(j*H)*100#percent\n", "T2=(h*v2*v)/(60)#C.H.U\n", "H1=(v2*q)/(j)#C.H.U/mim\n", "H2=H-(I1*q*v2)/(j*t)#C.H.U/mim\n", "T3=H1+H2#C.H.U/mim\n", "Tn=T2-T3#C.H.U/mim\n", "\n", "#RESULTS\n", "print\"the overall thermal effciency is\",round(t,3),\"%\"\n", "print\"the cylinder volume is\",round(V,3),\"ft^3\"\n", "print\"the thermal efficiency of steam engine is\",round(T1,3),\"%\"\n", "print\"total heat in oil.min is\",round(Tn,3),\"C.H.U/min\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "the overall thermal effciency is 39.727 %\n", "the cylinder volume is 20.709 ft^3\n", "the thermal efficiency of steam engine is 0.547 %\n", "total heat in oil.min is 24083.671 C.H.U/min\n" ] } ], "prompt_number": 10 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 8.12 Page 138" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#initialisation of variable\n", "from math import pi,sqrt,acos,asin,atan,cos,sin,tan\n", "r=14#in\n", "r1=1.8#in\n", "t=30.4#lb\n", "e=0.6#lb\n", "lam=1.4\n", "d=12#in\n", "d1=18#in\n", "v=10000#C.H.U/lb\n", "P=200#r m p\n", "\n", "#CALCULATIONS\n", "A=1-(1/(lam*(r)**0.4))*((r1)**lam-1)/(r1-1)#percent\n", "T=e*A#percent\n", "H=t/60*v#C.H.U\n", "H1=H*T#C.H.U\n", "I=(H1*1400)/(33000)#ln/in^2\n", "M=(I*33000)/(2*pi*144/4*d1/12*P/2)#lb/in^2\n", "\n", "#RESULTS\n", "print\"the indicated hourse-power and the mean effiective pressure of the engine is\",round(M,3),\"lb/in^2\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "the indicated hourse-power and the mean effiective pressure of the engine is 75.666 lb/in^2\n" ] } ], "prompt_number": 11 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 8.19 Page 140" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#initialisation of variable\n", "from math import pi,sqrt,acos,asin,atan,cos,sin,tan\n", "cv=0.1714#C.H.U\n", "R=100.3#ft.lb\n", "T=500#degree c\n", "J=1400#in\n", "Lam=R/J#C.H.U percent C\n", "\n", "#CALCULATIONS\n", "Cp=Lam+cv#C.H.U percent C\n", "\n", "#RESULTS\n", "print\"The specific heat at constant volume of a gaseous mixture is\",round(Cp,3),\"C.H.U %\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The specific heat at constant volume of a gaseous mixture is 0.243 C.H.U %\n" ] } ], "prompt_number": 12 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 8.20 Page 141" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#initialisation of variable\n", "from math import pi,sqrt,acos,asin,atan,cos,sin,tan\n", "a=0.124#in\n", "b=0.000025#in\n", "R=0.0671#heat units\n", "\n", "#CALCULATIONS\n", "Cp=(R+a+b)+b#T\n", "\n", "#RESULTS\n", "print\"the specific heat of a gas at constant volume is\",round(Cp,3),\"T\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "the specific heat of a gas at constant volume is 0.191 T\n" ] } ], "prompt_number": 13 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 8.21 Page 142" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#initialisation of variable\n", "from math import pi,sqrt,acos,asin,atan,cos,sin,tan\n", "v=18#ft^3\n", "p=14#lb/in^2\n", "p1=150#lb/in^2\n", "Cp=0.242#T\n", "Cv=0.171#T\n", "j=1400#ft\n", "R=j*(Cp-Cv)#ft.lb\n", "p2=144#ft\n", "I1=137500#ft/lb\n", "I2=6.37#ft/lb\n", "v2=3.282#ft^3\n", "\n", "#CALCULATIONS\n", "T=(p2*p*v)/R#Degree C\n", "T2=(p2*p1*v2)/(R)#Degree c\n", "W=Cp*(T2-T)+0.00002*((T2)**2-(T)**2)#C.H.U/lb\n", "C=v/v2#ratio\n", "\n", "#RESULTS\n", "print\"The work done the temperatures at the beginning and end of compression ratio is\",round(C,3),\"ratio\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The work done the temperatures at the beginning and end of compression ratio is 5.484 ratio\n" ] } ], "prompt_number": 14 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 8.22 Page 144" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#initialisation of variable\n", "from math import pi,sqrt,acos,asin,atan,cos,sin,tan\n", "r=12.5#rario\n", "p=0.39*10**6#ft.lb\n", "p1=14#lb/in^2\n", "t=373#Degree C\n", "g=18#ft^3\n", "t1=100#Degree C\n", "V=g/r#ft^3\n", "I=0.2*10**6#ft lb/lb\n", "T=0.59*10**6#ft.lb/lb\n", "D=0.221*10**6#ft.lb/lb\n", "A=0.095*10**6#ft.lb/lb\n", "E=0.264*10**6#ft.lb/lb\n", "E1=0.390*10**6#t.lb/lb\n", "\n", "#ALCULATIONS\n", "W=(E/E1)*100#ercent\n", "M=(E)/(144*(g-V))#b.in^2\n", "\n", "#RSULTS\n", "print\"the efficiency of the engine and the m e p on the assumption that the specific heats is\",round(M,3),\"lb in^2\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "the efficiency of the engine and the m e p on the assumption that the specific heats is 110.709 lb in^2\n" ] } ], "prompt_number": 16 } ], "metadata": {} } ] }