FluidDissipation is an open Modelica Library for calculations of pressure differences and heat transfer. It is developed by XRG Simulation.

The library is open source and can be downloaded freely in the version 1.1.3 for Dymola and MSL 3.2.
List of revisions:

Corrected Modelica syntax (w.r.t. annotation, enumerations, etc.).
Corrected an error in the momentum pressure loss calculation of FluidDissipation.Utilities.Functions.PressureLoss.TwoPhase.
dp_twoPhaseMomentum_DP.
Specified a type for A_cross in the same function. Correction of references in function Modelica.Fluid.Dissipation.Utilities.Functions.PressureLoss.TwoPhase.
SlipRatio.
Removed an erroneous limitation of angle phi for geodetic pipe pressure difference in function FluidDissipation.Utilities.Functions.PressureLoss.TwoPhase.
dp_twoPhaseGeodetic_DP.
Corrected many typos.