Calculates time derivative of specificEnthalpy_pT
function specificEnthalpy_pT_der input AbsolutePressure p "Pressure"; input Temperature T "Temperature"; input FixedPhase phase = 0 "2 for two-phase, 1 for one-phase, 0 if not known"; input Real der_p "Time derivative of pressure"; input Real der_T "Time derivative of temperature"; output Real der_h "Time derivative of specific enthalpy"; end specificEnthalpy_pT_der;