function VoidFraction extends Modelica.Icons.Function; input Modelica.Fluid.Dissipation.Utilities.Types.VoidFractionApproach voidFractionApproach = Dissipation.Utilities.Types.VoidFractionApproach.Homogeneous "Choice of void fraction approach" annotation( Dialog(group = "Choices")); input Boolean crossSectionalAveraged = true "= true, if cross sectional averaged void fraction, otherwise volumetric" annotation( Dialog); input SI.Density rho_g(min = Modelica.Constants.eps) "Density of gaseous phase" annotation( Dialog); input SI.Density rho_l(min = Modelica.Constants.eps) "Density of liquid phase" annotation( Dialog); input Real x_flow(min = 0, max = 1) = 0 "Mass flow rate quality" annotation( Dialog); output Real epsilon "Void fraction"; output Real slipRatio "Slip ratio"; end VoidFraction;