Derivative of isentropic specific enthalpy from p,s
function isentropicEnthalpy_der extends Modelica.Icons.Function; input SI.Pressure p "Pressure"; input SI.SpecificEntropy s "Specific entropy"; input Common.IF97BaseTwoPhase aux "Auxiliary record"; input Real p_der "Pressure derivative"; input Real s_der "Entropy derivative"; output Real h_der "Specific enthalpy derivative"; end isentropicEnthalpy_der;