//Chapter-5, Illustration 19, Page 269 //Title: Air Compressors //============================================================================= clc clear //INPUT DATA D=0.45;//Bore in m L=0.3;//Stroke in m C=0.05;//Ratio of clearance volume to swept volume P1=1;//Pressure at point 1 inn bar T1=291;//Temperature at point 1 in K P4=15;//Pressure at point 4 in bar n=1.3;//Adiabatic gas constant R=0.29;//Universal gas constant in kJ/kg-K //CALCULATIONS x=(n-1)/n;//Ratio k=(P4/P1)^(1/3);//Pressure ratio P2=k*P1;//Pressure at point 2 in bar P3=k*P2;//Pressure at point 1 in bar Vslp=(3.147*(D^2)*L)/4;//Swept volume of LP cylinder V7=C*Vslp;//Volume at point 7 in m^3 V1=Vslp+V7;//Volume at point 1 in m^3 V8=V7*(k^(1/n));//Volume at point 8 in m^3 EVs=(V1-V8)*1000;//Effective swept volume in litres T4=T1*(k^x);//Temperature at point 4 in K t4=T4-273;//Delivery temperature in oC DV=((P1*T4*(V1-V8))/(P4*T1))*1000;//Delivery volume per stroke in litres W=(3*R*T1*((k^x)-1))/x;//Workdone per kg of air in kJ //OUTPUT mprintf('Intermediate pressures are %3.3f bar and %3.3f bar \n Effective swept volume of LP cylinder is %3.2f litres \n Temperature of air delivered per stroke is %3.1f oC \n Volume of air delivered per stroke is %3.2f litres \n Work done per kg of air is %3.1f kJ',P2,P3,EVs,t4,DV,W) //==============================END OF PROGRAM=================================