An ideal gas is contained in a piston-cylinder device and undergoes a power cycle as follows:
1-2 isentropic compression from an initial temperature T1 = 20oC with a compression ratio r = 5
2-3 constant pressure heat addition
3-1 constant volume heat rejection
The gas has constant specific heats with cv = 0.7 kJ/kg·K and R = 0.3 kJ/kg·K.
(a) Sketch the P-v and T-s diagrams for the cycle.
(b) Determine the heat and work interactions for each process, in kJ/kg.
(c) Determine the cycle thermal efficiency.
(d) Obtain the expression for the cycle thermal efficiency as a function of the compression ratio r and ratio of specific heats k.