function isentropicEnthalpyApproximation extends Modelica.Icons.Function; input SI.Pressure p2 "Downstream pressure"; input ThermodynamicState state "Properties at upstream location"; input Boolean exclEnthForm = Functions.excludeEnthalpyOfFormation "If true, enthalpy of formation Hf is not included in specific enthalpy h"; input ReferenceEnthalpy refChoice = Functions.referenceChoice "Choice of reference enthalpy"; input SpecificEnthalpy h_off = Functions.h_offset "User defined offset for reference enthalpy, if referenceChoice = UserDefined"; output SI.SpecificEnthalpy h_is "Isentropic enthalpy"; end isentropicEnthalpyApproximation;