Version 4.1

Modelon Library 4.1 is part of Modelon’s 2022.2 release.

New Features


  • Added a compressor model TenCoefficientsCompressor parameterized by the 10 coefficients according to the AHRI-540 standard.
  • Added a low fildeity model for a positive displacement compressor Modelon.ThermoFluid.LowFidelity.IsothermalDisplacementCompressor, parameterized by constant volumetric and isothermal efficiencies.
  • In the existing positive displacement compressor model, Modelon.ThermoFluid.Compressors.PositiveDisplacementCompressor, added a compressor characteristic model that allow specifying constant volumetric, isentropic and mechanical efficiencies.


  • Medium interface GenericMedium has been extended with a sub-package "Stagnation", including models and functions fo facilitate more rigorous compressible flow calculations.
  • Added equations of state for ideal gases by Walsh & Fletcher for gas turbine engine calculations including dependency on air - burned fuel ratio.
  • In IdealGas and RealGas templates, the isentropicExponent function was modified to compute the property from density, velocity of sound and pressure. The result differs from the previous expression only for RealGas.
  • Added a function heatCapacityRatio to return the ratios of specific heats, cp/cv. For ideal gases, results are identical to isentropicExponent.
  • Added a function compressibilityFactor to HomogeneousMedium interface, and an implementation of it in IdealGas and RealGas templates.


Minor Improvements

  • Corrected errors in calculation of static head in LiquidReceiver and PhaseSeparator.
  • Added start attribute to variable p_sat in DistributedTwoPhase channel component.
  • Corrected an incorrect derivative annotation on function Modelon.Media.Templates.RealGas.setState_pTX.

Conversion of User Libraries

User libraries will automatically be converted from version 4.0. These conversions are made using the included conversion script: Modelon/Resources/Scripts/Convert_to_4.1.mos.