Editing Isentropic process (section)

===Isentropic efficiencies of steady-flow devices in thermodynamic systems===
Most steady-flow devices operate under adiabatic conditions, and the ideal process for these devices is the isentropic process. The parameter that describes how efficiently a device approximates a corresponding isentropic device is called isentropic or adiabatic efficiency.<ref name="Cengel Boles 2012"/>

Isentropic efficiency of turbines:
: <math> \eta_\text{t} = \frac{\text{actual turbine work}}{\text{isentropic turbine work}} = \frac{W_a}{W_s} \cong \frac{h_1 - h_{2a}}{h_1 - h_{2s}}. </math>

Isentropic efficiency of compressors:
: <math> \eta_\text{c} = \frac{\text{isentropic compressor work}}{\text{actual compressor work}} = \frac{W_s}{W_a} \cong \frac{h_{2s} - h_1}{h_{2a} - h_1}. </math>

Isentropic efficiency of nozzles:
: <math> \eta_\text{n} = \frac{\text{actual KE at nozzle exit}}{\text{isentropic KE at nozzle exit}} = \frac{V_{2a}^2}{V_{2s}^2} \cong \frac{h_1 - h_{2a}}{h_1 - h_{2s}}. </math>

For all the above equations:
: <math> h_1 </math> is the specific [[enthalpy]] at the entrance state,
: <math> h_{2a}</math> is the specific enthalpy at the exit state for the actual process,
: <math> h_{2s}</math> is the specific enthalpy at the exit state for the isentropic process.