In: Mechanical Engineering
1) A gas turbine operates on an ideal Joule cycle using air (γ = 1.4; R = 0.287 kJ/kg K) as working fluid. Air enters the compressor at temperature of 27◦C and pressure of 1.25 bar and is compressed to 7.6 bar. When the maximum cycle temperature is limited to 800 oC, calculate,
(i) the thermal efficiency and work ratio of the cycle
(ii) the temperature of air exiting the turbine and the change in specific entropy of turbine process if the isentropic efficiency of the turbine is 85%.
2) For an ideal Joule cycle, discuss the effects of pressure ratio on the thermal efficiency using T-s diagram.