New Release of FREE Modelica library FluidDissipation 1.1.8

fluid dissipation

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

A new two-phase pressure loss model (Mueller-Steinhagen Heck) is added to the FluidDissipation. The new model is invertible and by formulation linearized around zero mass flow. Thus, the numerical performance, especially of zero- and backflow calculations, is superior to other two phase pressure loss models. Furthermore, it was developed with a large data base of measurements and gives therefore reliable results within the model's scope.


The library is open source and can be downloaded in the version 1.1.8 for Dymola and MSL 3.2.2. Many functions are also compatible with OpenModelica.

List of revisions:

New features:

  • Added new function for pressure loss of two-phase flows in straight pipes (dp_twoPhaseOverall_DP)
  • Added application for dp_twoPhaseOverall_DP: FluidDissipation.Examples.TestCases.PressureLoss.StraightTwoPhasePipe

Corrected bugs:

  • Removed failure in kc_twoPhaseOverall_KC
  • Corrected failure status for StraightPipe.kc_overall
  • Removed superfluous calculations in StraightPipe.dp_twoPhaseOverall_DP
  • Removed obsolete annotations and corrected many typos
  • Removed many singularities in heat transfer functions for Reynolds Number at zero velocity
  • Corrected failure in SmoothPower_der
  • Corrected factor K_st1 in dp_TJoin
  • Corrected functions kc_twoPhase_boilingHorizontal and kc_twoPhase_boilingVertical

Changes with conversion:

  • Deleted model StateForHeatTransfer_TwoPhase which is now replaced by StateForHeatTransfer

Not backwards compatible changes:

  • Removed superfluous parameter "target" in TwoPhaseFlowHT_IN_var record. The following error will be raised by Dymola: "Modelica Unknown named argument 'target' for function FluidDissipation.HeatTransfer.StraightPipe.kc_twoPhaseOverall_KC_IN_var in MODELNAME. Please remove potential inputs for argument "target" in function calls manually
  • Removed superfluous input "d_hyd" from function ReynoldsNumber