Question

Air in a piston/cylinder goes through a Carnot cycle with the P-v diagram  The high and low temperatures are 1200 R and 600 R respectively. The heat added at the high temperature is 100 Btu/lbm and the lowest pressure in the cycle is 10 lbf/in.². Find the specific volume and pressure at all 4 states in the cycle assuming constant specific heats at 80 F. 

Answer 1

qH = 100 Btu/lbm T_H = 1200 R

T_L = 600 R P₃ = 10 lbf/in.² 

 C_v = 0.171 Btu/lbm R ; R = 53.34 ft-lbf/lbm-R 

 The states as

1: 1200 R , 2: 1200 R, 3: 10 psi, 600 R 4: 600 R