clear; clc; printf("\t\t\tProblem Number 6.10\n\n\n"); // Chapter 6: The Ideal Gas // Problem 6.10 (page no. 252) // Solution //The table in Appendix 3 does not give us the enthalpy data at 960R and 540R that we need.Interpolating yields // T hbar T hbar // 537 3729.5 900 6268.1 // 540 3750.4 960 6694.0 // 600 4167.9 1000 6977.9 //So, hbar540=3729.5+(3/63)*(4167.9-3729.5); //enthalpy //unit:Btu/lbm hbar960=6268.1+(60/100)*(6977.9-6268.1); //enthalpy //unit:Btu/lbm //Note that hbar is given for a mass of 1 lb mole.To obtain the enthalpy per pound,it is necessary to divide the values og h by the molecular weight,28. h2=6694.0; //enthalpy //unit:Btu/lbm h1=3750.4; //enthalpy //unit:Btu/lbm T2=500+460; //absolute final temperature //unit:R T1=80+460; //absolute initial temperature //unit:R cbar=(h2-h1)/(28*(T2-T1)); //The mean specific heat at constant pressure //unit:Btu/lbm*R printf("The mean specific heat at constant pressure is %f Btu/lbm*R\n",cbar); //With the more extesive Gas tables,these interpolations are avoided.The Gas Tables provide a relatively easy and accurate method of obtaining average specific heats.Also,these tables have been computerized for ease of application.