Derivative of pressure with regards to specific volume, at constant T
function dPressureVap_dSpecificVolume_Tv input Modelica.Units.SI.Temperature T "Temperature of refrigerant"; input Modelica.Units.SI.SpecificVolume v "Specific volume of refrigerant"; output Real dpdv(final unit = "Pa.kg/m3") "Derivative of pressure with regards to specific volume"; end dPressureVap_dSpecificVolume_Tv;