{ "cells": [ { "cell_type": "markdown", "metadata": {}, "source": [ "# Chapter 3: Internal Combustion Engines" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 3.1: Air_standard_efficiency_and_Indicated_Power_and_Indicated_thermal_efficiency.sce" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "//Chapter-3, Illustration 1, Page 139\n", "//Title: Internal Combustion Engines\n", "//=============================================================================\n", "clc\n", "clear\n", "\n", "//INPUT DATA\n", "d=200;//diameter of cylinder in mm\n", "L=300;//stroke of cylinder in mm\n", "Vc=1.73;//Clearance volume in litres\n", "imep=650;//indicated mean effective pressure in kN/(m^2)\n", "g=6.2;//gas consumption in (m^3)/h\n", "CV=38.5;//Calorific value in MJ/(m^3)\n", "y=1.4;//Ratio of specific heats\n", "N=150;//No. of firing cycles per minute\n", "\n", "//CALCULATIONS\n", "Vs=((3.1415/4)*(d^2)*L)*(10^-6);//Stroke volume in litres\n", "Vt=Vs+Vc;//Total volume in litres\n", "rv=(Vt/Vc);//Compression ratio\n", "n=(1-(1/rv^(y-1)))*100;//Air standard efficiency\n", "IP=imep*(Vs*10^-3)*(N/60);//Indicated power in kW\n", "F=(g*CV*1000)/3600;//Fuel energy input in kW\n", "nT=(IP/F)*100;//Indicated thermal efficiency\n", "\n", "//OUTPUT\n", "mprintf('Air Standard Efficiency is %3.1f percent \n Indicated Power is %3.1f kW \n Indicated thermal efficiency is %3.0f percent',n,IP,nT)\n", "\n", "\n", "\n", "\n", "//==============================END OF PROGRAM=================================" ] } , { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 3.2: Relative_efficiency_of_engine.sce" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "//Chapter-3, Illustration 2, Page 140\n", "//Title: Internal Combustion Engines\n", "//=============================================================================\n", "clc\n", "clear\n", "\n", "//INPUT DATA\n", "Vs=0.0008;//Swept volume in m^3\n", "Vc=0.00015;//Clearance volume in m^3\n", "CV=38;//Calorific value in MJ/(m^3)\n", "v=0.45;//volume in m^3\n", "IP=81.5;//Indicated power in kW\n", "y=1.4;//Ratio of specific heats\n", "\n", "//CALCULATIONS\n", "rv=(Vs+Vc)/Vc;//Compression ratio\n", "n=(1-(1/rv^(y-1)));//Air standard efficiency\n", "Ps=(v*CV*1000)/60;//Power supplied in kW\n", "nact=IP/Ps;//Actual efficiency\n", "nr=(nact/n)*100;//Relative efficiency\n", "\n", "//OUTPUT\n", "mprintf('Relative Efficiency is %3.2f percent',nr)\n", "\n", "\n", "\n", "//==============================END OF PROGRAM=================================" ] } , { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 3.3: EX3_3.sce" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "//Chapter-3, Illustration 3, Page 141\n", "//Title: Internal Combustion Engines\n", "//=============================================================================\n", "clc\n", "clear\n", "\n", "//INPUT DATA\n", "n=6;//No. of cylinders\n", "d=0.61;//Diameter in m\n", "L=1.25;//Stroke in m\n", "N=2;//No.of revolutions per second\n", "m=340;//mass of fuel oil in kg\n", "CV=44200;//Calorific value in kJ/kg\n", "T=108;//Torque in kN-m\n", "imep=775;//Indicated mean efective pressure in kN/(m^2)\n", "\n", "//CALCULATIONS\n", "IP=(imep*L*3.1415*(d^2)*N)/(8);//Indicated power in kW\n", "TotalIP=(n*IP);//Total indicated power in kW\n", "BP=(2*3.1415*N*T);//Brake power in kW\n", "PI=(m*CV)/3600;//Power input in kW\n", "nB=(BP/PI)*100;//Brake thermal efficiency\n", "bmep=(BP*8)/(n*L*3.1415*(d^2)*2);//Brake mean effective pressure in kN/(m^2)\n", "nM=(BP/TotalIP)*100;//Mechanical efficiency\n", "bsfc=m/BP;//Brake specific fuel consumption in kg/kWh\n", "\n", "//OUTPUT\n", "mprintf('Total Indicated Power is %3.1f kW \n Brake Power is %3.1f kW \n Brake thermal efficiency is %3.1f percent \n Brake mean effective pressure is %3.1f kN/(m^2) \n Mechanical efficiency is %3.1f percent \n Brake specific fuel consumption is %3.3f kg/kW.h',TotalIP,BP,nB,bmep,nM,bsfc)\n", "\n", "\n", "\n", "//==============================END OF PROGRAM=================================" ] } , { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 3.4: EX3_4.sce" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "//Chapter-3, Illustration 4, Page 142\n", "//Title: Internal Combustion Engines\n", "//=============================================================================\n", "clc\n", "clear\n", "\n", "//INPUT DATA\n", "Hm=21;//Mean height of indicator diagram in mm\n", "isn=27;//indicator spring number in kN/(m^2)/mm\n", "Vs=14;//Swept volume in litres\n", "N=6.6;//Speed of engine in rev/s\n", "Pe=77;//Effective brake load in kg\n", "Re=0.7;//Effective vrake radius in m\n", "mf=0.002;//fuel consumed in kg/s\n", "CV=44000;//Calorific value of fuel in kJ/kg\n", "mc=0.15;//cooling water circulation in kg/s\n", "Ti=311;//cooling water inlet temperature in K\n", "To=344;//cooling water outlet temperature in K\n", "C=4.18;//specific heat capacity of water in kJ/kg-K\n", "Ee=33.6;//Energy to exhaust gases in kJ/s\n", "g=9.81;//Acceleration due to geravity in m/(s^2)\n", "\n", "//CALCULATIONS\n", "imep=isn*Hm;//Indicated mean efective pressure in kN/(m^2)\n", "IP=(imep*Vs*N)/(2000);//Indicated Power in kW\n", "BP=(2*3.1415*N*g*Pe*Re)/1000;//Brake Power in kW\n", "nM=(BP/IP)*100;//Mechanical efficiency\n", "Ef=mf*CV;//Eneergy from fuel in kJ/s\n", "Ec=mc*C*(To-Ti);//Energy to cooling water in kJ/s\n", "Es=Ef-(BP+Ec+Ee);//Energy to surroundings in kJ/s\n", "p=(BP*100)/Ef;//Energy to BP in %\n", "q=(Ec*100)/Ef;//Energy to coolant in %\n", "r=(Ee*100)/Ef;//Energy to exhaust in %\n", "w=(Es*100)/Ef;//Energy to surroundings in %\n", "\n", "//OUTPUT\n", "mprintf('Indicated Power is %3.1f kW \n Brake Power is %3.0f kW \n Mechanical Efficiency is %3.0f percent \n \nENERGY BALANCE kJ/s Percentage \nEnergy from fuel %3.0f 100\nEnergy to BP %3.0f %3.0f\nEnergy to coolant %3.01f %3.1f\nEnergy to exhaust %3.1f %3.1f\nEnergy to surroundings, etc %3.1f %3.1f',IP,BP,nM,Ef,BP,p,Ec,q,Ee,r,Es,w)\n", "\n", "\n", "\n", "\n", "//==============================END OF PROGRAM=================================" ] } , { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 3.5: EX3_5.sce" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "//Chapter-3, Illustration 5, Page 143\n", "//Title: Internal Combustion Engines\n", "//=============================================================================\n", "clc\n", "clear\n", "\n", "//INPUT DATA\n", "t=30;//duration of trial in minutes\n", "N=1750;//speed in rpm\n", "T=330;//brake torque in Nm\n", "m=9.35;//mass of fuel in kg\n", "CV=42300;//Calorific value in kJ/kg\n", "mj=483;//jacket cooling water circulation in kg\n", "Ti=290;//inlet temperature in K\n", "T0=350;//outlet temperature in K\n", "ma=182;//air consumption in kg\n", "Te=759;//exhaust temperature in K\n", "Ta=256;//atmospheric temperature in K\n", "nM=0.83;//Mechanical efficiency\n", "ms=1.25;//mean specific heat capacity of exhaust gas in kJ/kg-K\n", "Cw=4.18;//specific heat capacity of water in kJ/kg-K\n", "\n", "//CALCULATIONS\n", "BP=(2*3.1415*T*N)/(60*1000);//Brake power in kW\n", "sfc=(m*2)/BP;//specific fuel consumption in kg/kWh\n", "IP=BP/nM;//Indicated power in kW\n", "nIT=((IP*3600)/(m*CV*2))*100;//Indicated thermal efficiency\n", "Ef=(m*CV)/t;//Eneergy from fuel in kJ/min\n", "EBP=BP*60;//Energy to BP in kJ/min\n", "Ec=(mj*Cw*(T0-Ti))/t;//Energy to cooling water in kJ/min\n", "Ee=((ma+m)*ms*(Te-Ti))/30;//Energy to exhaust in kJ/min\n", "Es=Ef-(EBP+Ec+Ee);//Energy to surroundings in kJ/min\n", "\n", "//OUTPUT\n", "mprintf('Brake power is %3.1f kW \n Specific fuel consumption is %3.3f kg/kWh \n Indicated thermal efficiency is %3.1f percent \n Energy from fuel is %3.0f kJ/min \n Energy to BP is %3.0f kJ/min \n Energy to cooling water is %3.0f kJ/min \n Energy to exhaust is %3.0f kJ/min \n Energy to surroundings is %3.0f kJ/min',BP,sfc,nIT,Ef,EBP,Ec,Ee,Es)\n", "\n", "\n", "\n", "\n", "\n", "\n", "//==============================END OF PROGRAM=================================" ] } , { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 3.6: Indicated_power_and_Mechanical_efficiency_of_engine.sce" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "//Chapter-3, Illustration 6, Page 144\n", "//Title: Internal Combustion Engines\n", "//=============================================================================\n", "clc\n", "clear\n", "\n", "//INPUT DATA\n", "BP0=12;//Brake Power output in kW\n", "BP1=40.5;//Brake Power in trial 1 in kW\n", "BP2=40.2;//Brake Power in trial 2 in kW\n", "BP3=40.1;//Brake Power in trial 3 in kW\n", "BP4=40.6;//Brake Power in trial 4 in kW\n", "BP5=40.7;//Brake Power in trial 5 in kW\n", "BP6=40.0;//Brake Power in trial 6 in kW\n", "\n", "//CALCULATIONS\n", "BPALL=BP0+BP6;//Total Brake Power in kW\n", "IP1=BPALL-BP1;//Indicated Power in trial 1 in kW\n", "IP2=BPALL-BP2;//Indicated Power in trial 2 in kW\n", "IP3=BPALL-BP3;//Indicated Power in trial 3 in kW\n", "IP4=BPALL-BP4;//Indicated Power in trial 4 in kW\n", "IP5=BPALL-BP5;//Indicated Power in trial 5 in kW\n", "IP6=BPALL-BP6;//Indicated Power in trial 6 in kW\n", "IPALL=IP1+IP2+IP3+IP4+IP5+IP6;//Total Indicated Power in kW\n", "nM=(BPALL/IPALL)*100;//Mechanical efficiency\n", "\n", "//OUTPUT\n", "mprintf('Indicated Power of the engine is %3.1f kW \n Mechanical efficiency of the engine is %3.1f percent',IPALL,nM)\n", "\n", "\n", "\n", "//==============================END OF PROGRAM=================================" ] } , { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 3.7: Engine_dimensions_and_Brake_power.sce" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "//Chapter-3, Illustration 7, Page 145\n", "//Title: Internal Combustion Engines\n", "//=============================================================================\n", "clc\n", "clear\n", "\n", "//INPUT DATA\n", "n=2;//No. of cylinders\n", "N=4000;//speed of engine in rpm\n", "nV=0.77;//Volumetric efficiency\n", "nM=0.75;//Mechanical efficiency\n", "m=10;//fuel consumed in lit/h\n", "g=0.73;//spcific gravity of fuel\n", "Raf=18;//air-fuel ratio\n", "Np=600;//piston speed in m/min\n", "imep=5;//Indicated mean efective pressure in bar\n", "R=281;//Universal gas constant in J/kg-K\n", "T=288;//Standard temperature in K\n", "P=1.013;//Standard pressure in bar\n", "\n", "//CALCULATIONS\n", "L=Np/(2*N);//Piston stroke in m\n", "mf=m*g;//mass of fuel in kg/h\n", "ma=mf*Raf;//mass of air required in kg/h\n", "Va=(ma*R*T)/(P*60*(10^5));//volume of air required in (m^3)/min\n", "D=sqrt((2*Va)/(nV*L*N*3.1415));//Diameter in m\n", "IP=(2*imep*100*L*3.1415*(D^2)*N)/(4*60);//Indicated Power in kW\n", "BP=nV*IP;//Brake Power in kW\n", "\n", "//OUTPUT\n", "mprintf('Piston Stroke is %3.3f m \n Bore diameter is %3.4f m \n Brake power is %3.1f kW',L,D,BP)\n", "\n", "\n", "\n", "//==============================END OF PROGRAM=================================" ] } ], "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 }