//Calculations on Otto cycle clc,clear //Given: r=8 //Compression ratio P1=1,P3=50 //Pressure at 1, 3 in bar T1=100+273 //Temperature at 1 in K m=1 //Air flow in kg R=0.287 //Specific gas constant in kJ/kgK g=1.4 //Specific heat ratio(gamma) //Solution: //Refer fig 2.22 //Point 1 V1=m*R*10^3*T1/(P1*10^5) //Ideal gas equation, Volume at 1 in m^3 //Point 2 P2=P1*r^g //Pressure at 2 in bar V2=V1/r //Volume at 2 in m^3 T2=P2*V2*T1/(P1*V1) //Temperature at 2 in K //Point 3 V3=V2 //Constant volume process, Volume at 3 in m^3 T3=(P3/P2)*T2 //Temperature at 3 in K (Wrong in book) //Point 4 P4=P3*(1/r)^g //Pressure at 4 in bar V4=V1 //Constant volume process, Volume at 4 in m^3 T4=T1*(P4/P1) //Temperature at 4 in K cv=R/(g-1) //Specific heat at constant volume in kJ/kgK ratio=(cv*(T3-T2))/(cv*(T4-T1)) //Ratio of heat supplied to the heat rejected (Round off error) //Results: printf("\n Point 1:\n Pressure = %d bar, Volume = %.4f m^3, Temperature = %d degreeC",P1,V1,T1-273) printf("\n\n Point 2:\n Pressure = %.1f bar, Volume = %.4f m^3, Temperature = %.1f degreeC",P2,V2,T2-273) printf("\n\n Point 3:\n Pressure = %.1f bar, Volume = %.4f m^3, Temperature = %.1f degreeC",P3,V3,T3-273) printf("\n\n Point 4:\n Pressure = %.2f bar, Volume = %.4f m^3, Temperature = %.1f degreeC",P4,V4,T4-273) printf("\n\n Ratio of heat supplied to the heat rejected = %.3f\n\n",ratio) //Textbook answer for T3 is wrong //Round off error in the value of 'ratio'