Air at 1600 k, 30 bar enters a turbine operating at steady state and expands adiabatically to the exit, where the pressure is 2.4 bar. the isentropic turbine efficiency is 90%. assume ideal gas behavior for the air and ignore kinetic and potential energy effects.

determine the temperature at the exit, in k, and the work developed, in kj per kg of air flowing.

q1/

the isentropic efficiency for a turbine operating with an ideal gas is evaluated in terms of the specific enthalpy at the actual exit state (h2) and the specific enthalpy at the exit state for isentropic expansion (h2s) as:

a

option a: (h1 – h2s) / (h1 – h2)

b

option b: (h1 – h2) / (h2s – h1)

c

option c: (h2s – h1) / (h1 – h2)

d

option d: (h1 – h2) / (h1 – h2s)