Consider an ideal Stirling-cycle engine with initial conditions as follows: pressure = 14.7 lbf/in², temperature = 80°F, compression ratio = 6, and maximum temperature = 2000°F. Calculate the maximum pressure in the cycle and the thermal efficiency of the cycle with and without regenerators.
a) Maximum pressure: 88.2 lbf/in², Thermal efficiency with regenerator: 0.45, Thermal efficiency without regenerator: 0.38
b) Maximum pressure: 176.4 lbf/in², Thermal efficiency with regenerator: 0.38, Thermal efficiency without regenerator: 0.45
c) Maximum pressure: 176.4 lbf/in², Thermal efficiency with regenerator: 0.45, Thermal efficiency without regenerator: 0.50
d) Maximum pressure: 88.2 lbf/in², Thermal efficiency with regenerator: 0.50, Thermal efficiency without regenerator: 0.45
