density derivative by pressure
function ddph_props extends Modelica.Icons.Function; input SI.Pressure p "pressure"; input SI.SpecificEnthalpy h "specific enthalpy"; input ThermalSeparation.Media.WaterBasedLiquid.BaseClasses.Common.IF97BaseTwoPhase aux "auxiliary record"; output SI.DerDensityByPressure ddph "density derivative by pressure"; end ddph_props;