An air standard cycle with constant specific heats is executed in a closed piston-cylinder system and is composed of the following three processes:
1-2 Constant volume heat addition
2-3 lsentropic expansion with an expansion ratio r 5 V3/V2
3-1 Constant pressure heat rejection
(a) Sketch the P-v and T-s diagrams for this cycle
(b) Obtain an expression for the back work ratio as a function of k and r
(c) Obtain an expression for the cycle thermal efficiency as a function of k and r
(d) Determine the value of the back work ratio and efficiency as r goes to unity
What do your results imply about the net work done by the cycle?