Isentropic efficiency Actual performance of a device Idealized device for the same inlet comparison state and same exit pressure Turbine:(expansion) Energy balance -T Actual expansion m (actual) h1-h2 h-h2s Isentropic expansion Minimum h2? 2 2s Constrain: 个 Accessible Oev states m =S2-S1≥0 P2 "="Adiabatic,no internal irreversibility 上游充通大学 April 28,2019 10 SHANGHAI JIAO TONG UNIVERSITYApril 28, 2019 10 Isentropic efficiency Actual performance of a device Idealized device for the same inlet state and same exit pressure comparison Turbine: (expansion) Energy balance Minimum h2 ? Constrain: “=”: Adiabatic, + no internal irreversibility (actual)