This function calculates the derivative of liquid entropy of R134a with regard to the state variable p (absolute pressure). The non-derivative function is bubbleEntropy.
It is only valid in the two-phase region (i.e., ptriple ≤ p ≤ pcrit ).
function dBubbleEntropy_dPressure extends Modelica.Icons.Function; input SaturationProperties sat "Saturation properties | pressure is used for interpolation"; output Real dsldp "Derivative of liquid specific entropy in two-phase region w.r.t. pressure"; end dBubbleEntropy_dPressure;