This function computes the number of phases for R1234yf depending
on the inputs for absolute pressure and specific enthalpy. It makes
use of cubic spline functions for liquid and vapor specific
enthalpy.
function getPhase_ph
extends Modelica.Icons.Function;
input Modelica.Units.SI.Pressure p "pressure";
input Modelica.Units.SI.SpecificEnthalpy h "specific enthalpy";
output Integer phase "number of phases";
end getPhase_ph;