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diff --git a/Elements_of_Mechanical_Engineering_by_R_K_Rajput/7-Internal_Combustion_Engines.ipynb b/Elements_of_Mechanical_Engineering_by_R_K_Rajput/7-Internal_Combustion_Engines.ipynb new file mode 100644 index 0000000..82af122 --- /dev/null +++ b/Elements_of_Mechanical_Engineering_by_R_K_Rajput/7-Internal_Combustion_Engines.ipynb @@ -0,0 +1,743 @@ +{ +"cells": [ + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "# Chapter 7: Internal Combustion Engines" + ] + }, +{ + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## Example 7.10: Example_10.sce" + ] + }, + { +"cell_type": "code", + "execution_count": null, + "metadata": { + "collapsed": true + }, + "outputs": [], +"source": [ +"clc\n", +"clear\n", +"//DATA GIVEN\n", +"n=4; //no. of cylinders\n", +"BP=30; //Brake Power in kW\n", +"N=2500; //engine speed in R.P.M.\n", +"Pmi=8; //mean effective pressure in bar\n", +"ETAm=0.8; //mechanical efficiency\n", +"ETAthb=0.28; //brake thermal efficiency\n", +"C=43900; //calorific value of fuel used in kJ/kg\n", +"k=1; //for 2-stroke cylinder\n", +"\n", +"//mechanical efficiency, ETAm=BP/IP\n", +"IP=BP/ETAm;\n", +"//INDICTED POWER ,I.P.=(n*PMI*l*A*N*k*10)/6 kW\n", +"//L=1.5D,\n", +"D=((6*IP)/(10*k*N*n*Pmi*1.5*(%pi/4)))^(1/3); //bore diameter in m\n", +"L=1.5*D; //length of stroke in m\n", +"//Brake thermal efficiency, ETAtb=BP/(Mf*C)\n", +"Mf=BP/(ETAthb*C); //fuel consumption in kg/hr\n", +"\n", +"printf(' (i) The Bore diameter is: %5.3f m or %2.0f mm.\n',D,(D*1000));\n", +"printf(' The Stoke length is: %2.0f mm.\n',(L*1000));\n", +"printf(' (ii) The Fuel consumption is: %5.5f kg/s or %3.2f kg/hr. \n',Mf,(Mf*3600));" + ] + } +, +{ + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## Example 7.11: Example_11.sce" + ] + }, + { +"cell_type": "code", + "execution_count": null, + "metadata": { + "collapsed": true + }, + "outputs": [], +"source": [ +"clc\n", +"clear\n", +"//DATA GIVEN\n", +"n=6; //no. of cylinders\n", +"Pdisp=700; //piston disp per cylinder in cm^3\n", +"P=78; //power developed in kW\n", +"N=3200; //engine speed in R.P.M.\n", +"Mf=27; //mass of fuel used in kg/hr\n", +"C=44000; //calorific value of fuel used in kJ/kg\n", +"afr=12; //air fuel ratio\n", +"Pa=0.9; //intake air pressure in bar\n", +"Ta=32+273; //intake air tempertaure in K\n", +"R=0.287; //gas constant for air in kJ/kgK\n", +"k=0.5; //for 4-stroke cylinder\n", +"\n", +"Ma=afr*Mf; //mass of air\n", +"//by eq. pa*Va=Ma*R*Ta\n", +"Va=Ma*R*Ta/Pa/100; //volume of intake air in m^3/hr\n", +"Vswept=(Pdisp/10^6)*n*(N/2)*60; //volume swept in m^3/hr\n", +"ETAvol=Va/Vswept; //volumetric efficiency\n", +"\n", +"//Brake thermal efficiency , ETAbt=brake work/heat supplied by the fuel\n", +"ETAbt=P/(Mf*C/3600);\n", +"//Brake Power, BP = (2*pi)N*Tb/(60*1000) kW\n", +"Tb=P*60/(2*%pi*N); //brake torque in kNm\n", +"\n", +"printf(' (i) The Volumetric efficiency is: %5.3f or %5.1f percent. \n',ETAvol,(ETAvol*100));\n", +"printf(' (ii) The Brake thermal efficiency is: %5.4f or %5.2f percent. \n',ETAbt,(ETAbt*100));\n", +"printf(' (iii) The Brake Torque is: %5.4f kNm. \n',Tb);" + ] + } +, +{ + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## Example 7.12: Example_12.sce" + ] + }, + { +"cell_type": "code", + "execution_count": null, + "metadata": { + "collapsed": true + }, + "outputs": [], +"source": [ +"clc\n", +"clear\n", +"//DATA GIVEN\n", +"//L=1.5D\n", +"n=6; //no. of cylinders\n", +"Vs=1.75; //stroke volume in litres\n", +"IP=26.3; //power developed in kW\n", +"Ne=504; //engine speed in R.P.M.\n", +"Pmi=6; //mean effective pressure in bar\n", +"k=0.5; //for 4-stroke cylinder\n", +"\n", +"//INDICTED POWER ,I.P.=(n*PMI*l*A*N*k*10)/6 kW\n", +"//L*A=Vs\n", +"Na=IP*6/(n*Pmi*(Vs/10^3)*k*10); //actual speed in R.P.M\n", +"Fa=Na*n*k; //actual no. of fires in one minute\n", +"Fe=Ne*n/2; //expected no. of fires in one minute\n", +"Fm=Fe-Fa; //misfires per minute\n", +"Fmavg=Fm/n; //avg. no. of times each cylinder misfires in one minute\n", +"\n", +"printf('The Average no. of times each cylinder misfires in one minute is: %1.0f.\n',Fmavg);" + ] + } +, +{ + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## Example 7.13: Example_13.sce" + ] + }, + { +"cell_type": "code", + "execution_count": null, + "metadata": { + "collapsed": true + }, + "outputs": [], +"source": [ +"clc\n", +"clear\n", +"//DATA GIVEN\n", +"D=0.075; //bore in m\n", +"L=0.09; //stroke length in m\n", +"n=4; //no. of cylinders\n", +"erar=39/8; //engine to rear axle ratio =39:8\n", +"Dw=0.65; //wheel diameter with tyre fully inflated in m\n", +"Fc=0.227; //petrol consumption for a distance of 3.2 km at a speed of 48 km/hr\n", +"Pmi=5.625; //mean effective pressure in bar\n", +"C=43470; //calorific value of fuel used in kJ/kg\n", +"k=0.5; //for 4-stroke cylinder\n", +"\n", +"s=48*1000/60; //speed of car in m/min\n", +"//if Nt rev are made by tyre per minute, speed=pi*Dw*Nt\n", +"Nt=s/(%pi*Dw); //R.P.M.\n", +"//as engine to rear axle ratio is 39:8\n", +"Ne=erar*Nt; //speed of enfine shaft in R.P.M.\n", +"//INDICTED POWER ,I.P.=(n*PMI*l*A*N*k*10)/6 kW\n", +"A=(%pi/4)*(D^2);\n", +"IP=(n*Pmi*L*A*Ne*k*10)/6;\n", +"\n", +"s=s/1000; //speed of car in km/min\n", +"t=3.2/s; //time in min for covering 3.2 km \n", +"//petrol consumption for a distance of 3.2 km aat a speed of 48 km/hr is 0.227kg\n", +"Mf=Fc/(t*60); //fuel consumed per sec\n", +"ETAthi=IP/(Mf*C); //Indicated fuel efficiency\n", +"\n", +"printf(' (i) The Indicated Power developed is: %5.2f kW. \n',IP);\n", +"printf(' (ii) The Indicated thermal efficiency is: %1.3f or %2.1f percent. \n',ETAthi,(ETAthi*100));" + ] + } +, +{ + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## Example 7.14: Example_14.sce" + ] + }, + { +"cell_type": "code", + "execution_count": null, + "metadata": { + "collapsed": true + }, + "outputs": [], +"source": [ +"clc\n", +"clear\n", +"//DATA GIVEN\n", +"D=0.25; //cylinder diameter in m\n", +"L=0.4; //stroke length in m\n", +"Pmg=7; //Gross mean effective pressure in bar\n", +"Pmp=0.5; //Pumping mean effective pressure in bar\n", +"N=250; //engine speed in R.P.M.\n", +"NBL=1080; //net load on the brake (W-S) in N\n", +"Db=1.5; //effective diameter of the brake in m\n", +"Fc=10; //fuel used per hr in kg\n", +"C=44300; //calorific value of fuel used in kJ/kg\n", +"n=1; //no. of cylinders\n", +"k=0.5; //for 4-stroke cylinder\n", +"\n", +"//INDICTED POWER ,I.P.=(n*PMI*l*A*N*k*10)/6 kW\n", +"Pm=Pmg-Pmp;\n", +"A=(%pi/4)*(D^2);\n", +"IP=(n*Pm*L*A*N*k*10)/6;\n", +"BP=NBL*(%pi)*(Db)*N/(60*1000);\n", +"ETAm=BP/IP; //mechanical efficiency\n", +"Mf=Fc/3600;\n", +"ETAthi=IP/(Mf*C); //Indicated thermal efficiency\n", +"\n", +"printf(' (i) The Indicated Power, I.P. is: %5.2f kW. \n',IP);\n", +"printf(' (ii) The Brake Power, B.P. is: %2.1f kW. \n',BP);\n", +"printf('(iii) Mechanical efficiency is: %5.3f or %2.1f percent.\n',ETAm,(ETAm*100));\n", +"printf(' (iv) Indicated thermal efficiency is: %5.3f or %2.1f percent.\n',ETAthi,(ETAthi*100));\n", +"\n", +"\n", +"" + ] + } +, +{ + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## Example 7.15: Example_15.sce" + ] + }, + { +"cell_type": "code", + "execution_count": null, + "metadata": { + "collapsed": true + }, + "outputs": [], +"source": [ +"clc\n", +"clear\n", +"//DATA GIVEN\n", +"ETAthb=30; //Brake thermal efficiency in %\n", +"afr=20; //air fuel ratio by weight\n", +"C=41800; //calorific value of fuel used in kJ/kg\n", +"\n", +"//Brake thermal efficiency, ETAthb=work produced/heat supplied\n", +"work=(ETAthb/100)*C; //work produced per kg of fuel\n", +"//STP conditions refer to 1.0132 bar and 15 deg celsius\n", +"m=afr; //mass of air per kg of fuel\n", +"R=287;\n", +"V=m*R*(15+273)/(1.0132*10^5); //volume of air used\n", +"//Brake mean effective pressure, Pmb=work done/cylinder volume\n", +"Pmb=(work*1000)/(V*10^5);\n", +"\n", +"printf('The Brake mean effective pressure, Pmb is: %2.2f bar.\n',Pmb);" + ] + } +, +{ + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## Example 7.16: Example_16.sce" + ] + }, + { +"cell_type": "code", + "execution_count": null, + "metadata": { + "collapsed": true + }, + "outputs": [], +"source": [ +"clc\n", +"clear\n", +"//DATA GIVEN\n", +"V1=0.216; //gas consumption in m^3/min\n", +"P1=75; //gas temperature in mm of water\n", +"T1=17+273; //gas tempertaure in K\n", +"m=2.84; //air consumption in kg/min\n", +"Ta=17+273; //air tempertaure in K\n", +"br=745; //barometer reading in mm of Hg\n", +"D=0.25; //bore of engine cylinder in m\n", +"L=0.475; //stroke length in m\n", +"N=240; //engine speed in R.P.M.\n", +"R=287; //gas constant for air in J/kgK\n", +"n=1; //no. of cylinders\n", +"k=1; //for 2-stroke cylinder\n", +"\n", +"P1=br+P1/13.6; //pressure of the gas\n", +"//at NTP\n", +"P2=760; //mm of Hg\n", +"T2=0+273; //in K\n", +"//P1*V1/T1=P2*V2/T2\n", +"V2=P1*V1*T2/(P2*T1); //volume of gas used at NTP in m^3\n", +"Vg=V2/(N/2); //gas used per stroke in m^3\n", +"\n", +"//PV=mRT\n", +"P2=1.0132*10^5;\n", +"V=m*R*T2/P2; //volume occupied by air in m^3/min\n", +"Va=V/(N/2); //air used per stroke in m\n", +"\n", +"Vmix=Vg+Va; //mixture of gas and air in m^3\n", +"\n", +"//ETAvol=(actual volume of mixture drawn per stroke at NTP)/(swept volume of system)\n", +"ETAvol=Vmix/((%pi/4)*D^2*L);\n", +"\n", +"printf(' The Volumetric efficiency is: %3.3f or %3.1f percent. \n',ETAvol,(ETAvol*100));" + ] + } +, +{ + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## Example 7.17: Example_17.sce" + ] + }, + { +"cell_type": "code", + "execution_count": null, + "metadata": { + "collapsed": true + }, + "outputs": [], +"source": [ +"clc\n", +"clear\n", +"//DATA GIVEN\n", +"t=1; //duration of trial in hr\n", +"N=14000; //revolutions\n", +"mc=500; //no. of missed cycles\n", +"NBL=1470; //Net brake load (W-S) in N\n", +"Pmi=7.5; //mean effective pressure in bar\n", +"Vg=20000/3600; //gas consumption in litres/s\n", +"C=21; //LCV of gas at sipply conditions in kJ/litre\n", +"D=0.25; //cylinder diameter in m\n", +"L=0.4; //stroke length in m\n", +"Cb=4; //effective brake circumference in m\n", +"r=6.5; //compression ratio\n", +"n=1; //no. of cylinders\n", +"k=0.5; //for 4-stroke cylinder\n", +"\n", +"//gamma for air, g=1.4\n", +"g=1.4;\n", +"\n", +"//INDICTED POWER ,I.P.=(n*PMI*l*A*N*k*10)/6 kW\n", +"Nk=(N*k-mc)/60; //(N*k)-working cycles/min\n", +"A=(%pi/4)*(D^2);\n", +"IP=(n*Pmi*L*A*Nk*10)/6;\n", +"N=N/60;\n", +"BP=NBL*(Cb)*N/(60*1000);\n", +"eta=BP/IP; //mechanical efficiency\n", +"ETAthi=IP/(Vg*C); //Indicated thermal efficiency\n", +"\n", +"//relative efficiency, ETArel=ETAthi/ETAas\n", +"//ETAas=1-1/(r^(g-1))\n", +"ETAas=1-1/(r^(g-1)); //air-standard efficiency\n", +"ETArel=ETAthi/ETAas; //relative efficiency\n", +"\n", +"printf(' (i) The Indicated Power, I.P. is: %5.2f kW. \n',IP);\n", +"printf(' (ii) The Brake Power, B.P. is: %5.2f kW. \n',BP);\n", +"printf(' (iii) Mechanical efficiency is: %5.3f or %2.1f percent.\n',eta,(eta*100));\n", +"printf(' (iv) The Indicated thermal efficiency is: %2.2f or %2.0f percent. \n',ETAthi,(ETAthi*100));\n", +"printf(' (v) The Relative efficiency is: %2.3f or %2.1f percent. \n',ETArel,(ETArel*100));" + ] + } +, +{ + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## Example 7.1: Example_1.sce" + ] + }, + { +"cell_type": "code", + "execution_count": null, + "metadata": { + "collapsed": true + }, + "outputs": [], +"source": [ +"clc\n", +"clear\n", +"//DATA GIVEN\n", +"Pmi=6; //mean effective pressure in bar\n", +"N=1000; //engine speed in R.P.M.\n", +"D=0.11; //diameter of piston in m\n", +"L=0.14; //stroke length in m\n", +"n=1; //no. of cylinders\n", +"k=1; //for 2-stroke cylinder\n", +"\n", +"//INDICTED POWER ,I.P.=(n*PMI*l*A*N*k*10)/6 kW\n", +"A=(%pi/4)*(D^2);\n", +"IP=(n*Pmi*L*A*N*k*10)/6;\n", +"\n", +"printf('The Indicted Power developed is: %2.1f kW.',IP);" + ] + } +, +{ + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## Example 7.2: Example_2.sce" + ] + }, + { +"cell_type": "code", + "execution_count": null, + "metadata": { + "collapsed": true + }, + "outputs": [], +"source": [ +"clc\n", +"clear\n", +"//DATA GIVEN\n", +"//L=1.5D\n", +"n=4; //no. of cylinders\n", +"P=14.7; //power developed in kW\n", +"N=1000; //engine speed in R.P.M.\n", +"Pmi=5.5; //mean effective pressure in bar\n", +"k=0.5; //for 4-stroke cylinder\n", +"\n", +"//INDICTED POWER, I.P.=(n*PMI*l*A*N*k*10)/6 kW\n", +"//A=(pi/4)*D^2,\n", +"//L=1.5D,\n", +"D=((6*P)/(10*k*N*n*Pmi*1.5*(%pi/4)))^(1/3); //bore diameter in m\n", +"L=1.5*D; //length of stroke in m\n", +"\n", +"printf('The Bore diameter is: %5.2f mm.\n',(D*1000));\n", +"printf(' The Stoke length is: %5.2f mm.\n',(L*1000));" + ] + } +, +{ + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## Example 7.3: Example_3.sce" + ] + }, + { +"cell_type": "code", + "execution_count": null, + "metadata": { + "collapsed": true + }, + "outputs": [], +"source": [ +"clc\n", +"clear\n", +"//DATA GIVEN\n", +"Db=0.6; //diameter of brake wheel in m\n", +"d=0.026; //diameter of rope in m\n", +"W=200; //dead load on the brake in N\n", +"S=30; //spring balance reading in N\n", +"N=450; //engine speed in R.P.M.\n", +"\n", +"//Brake Power, B.P.=(W-S)(pi)(Db+d)N/(60*1000) kW\n", +"BP=(W-S)*(%pi)*(Db+d)*N/(60*1000);\n", +"\n", +"printf('The Brake Power, B.P. is: %2.1f kW.\n',BP);" + ] + } +, +{ + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## Example 7.4: Example_4.sce" + ] + }, + { +"cell_type": "code", + "execution_count": null, + "metadata": { + "collapsed": true + }, + "outputs": [], +"source": [ +"clc\n", +"clear\n", +"//DATA GIVEN\n", +"T=175; //torque due to brake load in Nm\n", +"N=500; //engine speed in R.P.M.\n", +"\n", +"//Brake Power, BP = (2*pi)NT/(60*1000) kW\n", +"BP = (2*%pi)*N*T/(60*1000); \n", +"\n", +"printf('The Brake Power, B.P. is: %4.2f kW.\n',BP);" + ] + } +, +{ + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## Example 7.5: Example_5.sce" + ] + }, + { +"cell_type": "code", + "execution_count": null, + "metadata": { + "collapsed": true + }, + "outputs": [], +"source": [ +"clc\n", +"clear\n", +"//DATA GIVEN\n", +"D=0.3; //bore of engine cylinder in m\n", +"L=0.45; //stroke length in m\n", +"N=300; //engine speed in R.P.M.\n", +"Pmi=6; //mean effective pressure in bar\n", +"NBL=1.5; //Net brake load (W-S) in kN\n", +"Db=1.8; //diameter of brake drum\n", +"d=0.02; //brake rope diameter\n", +"n=1; //no. of cylinders\n", +"k=0.5; //for 4-stroke cylinder\n", +"\n", +"//INDICTED POWER ,I.P.=(n*PMI*l*A*N*k*10)/6 kW\n", +"A=(%pi/4)*(D^2);\n", +"IP=(n*Pmi*L*A*N*k*10)/6;\n", +"BP=NBL*(%pi)*(Db+d)*N/(60);\n", +"eta=BP/IP; //mechanical efficiency\n", +"\n", +"printf(' (i) The Indicted Power, I.P. is: %5.2f kW. \n',IP);\n", +"printf(' (ii) The Brake Power, B.P. is: %5.2f kW. \n',BP);\n", +"printf('(iii) Mechanical efficiency is: %5.4f or %5.2f percent.\n',eta,(eta*100));" + ] + } +, +{ + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## Example 7.6: Example_6.sce" + ] + }, + { +"cell_type": "code", + "execution_count": null, + "metadata": { + "collapsed": true + }, + "outputs": [], +"source": [ +"clc\n", +"clear\n", +"//DATA GIVEN\n", +"D=0.2; //diameter of engine cylinder in m\n", +"L=0.350; //length of stroke in m\n", +"Pmico=6.5; //mean effective pressure on cover side in bar\n", +"Pmicr=7; //mean effective pressure on crank side in bar\n", +"N=420; //engine speed in R.P.M.\n", +"Drod=0.02; //diameter of piston rod in m\n", +"W=1370; //dead load on the brake in N\n", +"S=145; //spring balance reading in N\n", +"Db=1.2; //diameter of brake wheel in m\n", +"d=0.02; //diameter of rope in m\n", +"n=1; //no. of cylinders\n", +"k=0.5; //for 4-stroke cylinder\n", +"\n", +"//INDICTED POWER ,I.P.=(n*Pmi*l*A*N*k*10)/6 kW\n", +"Aco=(%pi/4)*(D^2); //area of cylinder om cover end in m^2\n", +"Acr=(%pi/4)*(D^2-Drod^2); //area of cylinder om crank end in m^2\n", +"IPco=(n*Pmico*L*Aco*N*k*10)/6; //IP on cover end side in kW\n", +"IPcr=(n*Pmicr*L*Acr*N*k*10)/6; //IP on crank end side in kW\n", +"IPtotal=IPco+IPcr; //IP total in kW\n", +"\n", +"//Brake Power, B.P.=(W-S)(pi)(Db+d)N/(60*1000) kW\n", +"BP=(W-S)*(%pi)*(Db+d)*N/(60*1000);\n", +"\n", +"eta=BP/IPtotal; //mechanical efficiency\n", +"\n", +"printf('Mechanical efficiency is: %5.4f or %5.2f percent.\n',eta,(eta*100));" + ] + } +, +{ + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## Example 7.7: Example_7.sce" + ] + }, + { +"cell_type": "code", + "execution_count": null, + "metadata": { + "collapsed": true + }, + "outputs": [], +"source": [ +"clc\n", +"clear\n", +"//DATA GIVEN\n", +"IP=30; //indicted power in kW\n", +"BP=26; //Brake Power in kW\n", +"N=1000; //engine speed in R.P.M.\n", +"F=0.35; //fuel per brake power hour in kg/BP/h\n", +"C=43900; //calorific value of fuel used in kJ/kg\n", +"\n", +"Fc=F*BP; //fuel consumption per hour \n", +"Mf=Fc/3600;\n", +"ETAti=IP/(Mf*C); //Indicted thermal eficiency\n", +"ETAtb=BP/(Mf*C); //Brake thermal efficiency\n", +"ETAm=BP/IP; //Mechanical efficiency\n", +"\n", +"printf(' (i) The Indicted thermal eficiency is: %5.3f or %2.1f percent. \n',ETAti,(ETAti*100));\n", +"printf(' (ii) The Brake thermal efficiency is: %5.3f or %2.1f percent. \n',ETAtb,(ETAtb*100));\n", +"printf('(iii) Mechanical efficiency is: %5.3f or %2.1f percent. \n',ETAm,(ETAm*100));" + ] + } +, +{ + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## Example 7.8: Example_8.sce" + ] + }, + { +"cell_type": "code", + "execution_count": null, + "metadata": { + "collapsed": true + }, + "outputs": [], +"source": [ +"clc\n", +"clear\n", +"//DATA GIVEN\n", +"Db=0.75; //diameter of brake pulley in m\n", +"d=0.05; //diameter of rope in m\n", +"W=400; //dead load on the brake in N\n", +"S=50; //spring balance reading in N\n", +"Fc=4.2; //fuel consumption in kg/hr\n", +"N=1000; //rated engine speed in R.P.M.\n", +"C=43900; //calorific value of fuel used in kJ/kg\n", +"n=1; //no. of cylinders\n", +"k=0.5; //for 4-stroke cylinder\n", +"\n", +"\n", +"//Brake Power, B.P.=(W-S)(pi)(Db+d)N/(60*1000) kW\n", +"BP=(W-S)*(%pi)*(Db+d)*N/(60*1000);\n", +"sfc=Fc/BP; //brake specific fuel consumption in kg/kWhr\n", +"Mf=Fc/3600;\n", +"ETAtb=BP/(Mf*C); //Brake thermal efficiency\n", +"\n", +"printf(' (i) The Brake specific fuel consumption, s.f.c (brake) is: %5.3f kg/kWh. \n',sfc);\n", +"printf(' (ii) The Brake thermal efficiency is: %5.3f or %2.1f percent. \n',ETAtb,(ETAtb*100));\n", +"\n", +"" + ] + } +, +{ + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## Example 7.9: Example_9.sce" + ] + }, + { +"cell_type": "code", + "execution_count": null, + "metadata": { + "collapsed": true + }, + "outputs": [], +"source": [ +"clc\n", +"clear\n", +"//DATA GIVEN\n", +"n=6; //no. of cylinders\n", +"D=0.09; //bore of each cylinder in m\n", +"L=0.1; //length of stroke in m\n", +"r=7; //compression ratio\n", +"ETArel=0.55; //relative efficiency\n", +"Fsc=0.3; //indicated specific fuel consumption in kg/kWh\n", +"Pmi=8.6; //indicated mean effective pressure in bar\n", +"N=2500; //engine speed in R.P.M.\n", +"k=0.5; //for 4-stroke cylinder\n", +"\n", +"//Air standard efficiency, ETAair=1-1/(r^(gamma-1))\n", +"g=1.4; //gamma of air=1.4\n", +"ETAair=1-1/(r^(g-1));\n", +"//Indicated thermal efficiency, ETArel=ETAthi/ETAair;\n", +"ETAthi=ETArel*ETAair;\n", +"//Indicted thermal eficiency, ETAthi=IP/(Mf*C)\n", +"Mf=Fsc/3600;\n", +"//taking IP=1,\n", +"C=1/(ETAthi*Mf); //calorific value in kJ/kg\n", +"//INDICTED POWER ,I.P.=(n*Pmi*l*A*N*k*10)/6 kW\n", +"A=(%pi/4)*(D^2);\n", +"IP=(n*Pmi*L*A*N*k*10)/6;\n", +"Fc=Fsc*IP; //total fuel consumption in kg/hr\n", +"\n", +"printf(' (i) The Calorific value of coal, C is: %5.0f kJ/kg. \n',C);\n", +"printf(' (ii) The Fuel consumption is: %5.2f kg/h. \n',Fc);\n", +"\n", +"//NOTE:\n", +"//ans of calorific value here is exact, while in TB its rounded off value" + ] + } +], +"metadata": { + "kernelspec": { + "display_name": "Scilab", + "language": "scilab", + "name": "scilab" + }, + "language_info": { + "file_extension": ".sce", + "help_links": [ + { + "text": "MetaKernel Magics", + "url": "https://github.com/calysto/metakernel/blob/master/metakernel/magics/README.md" + } + ], + "mimetype": "text/x-octave", + "name": "scilab", + "version": "0.7.1" + } + }, + "nbformat": 4, + "nbformat_minor": 0 +} |