Version 3.7

Modelon Library 3.7 is part of Modelon’s 2021.2 release.

New Features


New features using spline-based table lookup (SBTL):

  • Added new R134a SBTL media based on RefProp with extended range. Here is the R134aSBTL Media.
  • All functions from the media interface are implemented, so that SBTL media can replace Helmholtz-energy based media in any model without changes to that model.
  • Added derivatives, so that tools can generate analytic Jacobians.


  • Added support for compressibility effects in pipe components. See an overview on this page.
  • Added new type of heat exchanger StaticEffectivenessFromQTable. The rate of heat transfer is mapped directly from the mass flow rates of both mediums via a look-up table using linear interpolation.


  • Introduced a set of basic interfaces and components for modeling multi-phase AC (alternating currents) and magnetic circuits.


  • Introduced a feature for defining stochastic parameters based on statistical distributions.



  • Improved the Equation of state of Helmholtz media to perform in the critical pressure.
  • Improved the Equation of state of Helmholtz and SBTL by moving the fluid constant, limits, extendedFluidConstants and supercritical use from the templates to the interface of Helmholtz and SBTL EOS.
  • Major improvements using spline-based table lookup (SBTL):
    • Increased range where media can be used.
    • Improved robustness and better test coverage.
    • Restructuring to reduce code duplication.


  • In the AirDataImplementations package, an additional template model has been added and the common variables and equations have been moved from XYZ and AED to the Base model.
  • AirData models have been updated to follow the standard naming convention.
  • A wide range of temperature functions like coldDay and hotDay has been added as users choice for the US76 atmosphere.

Drive Cycle Source Blocks

Almost 60 pre-defined, industry-standard source data blocks have been added. The new drive cycle blocks can be found in DriveCycles.

Minor Changes

  • Added new friction model ReentrantIntake
  • The following friction models have been updated to account for bidirectional flow:
    • Modelon.ThermoFluid.FlowResistances.FrictionModels.Contraction
    • Modelon.ThermoFluid.FlowResistances.FrictionModels.AbruptContraction
    • Modelon.ThermoFluid.FlowResistances.FrictionModels.ConicalExpansion
    • Modelon.ThermoFluid.FlowResistances.FrictionModels.AbruptExpansion
    • Modelon.ThermoFluid.FlowResistances.FrictionModels.FlushMountedIntake
  • Flow coefficients in valves:
    • Move options for flow coefficient parametrization to a dedicated model
    • Add a separate model to calculate the resulting valve area based on the parametrization choice.
    • Apply these parametrization templates to the compressible and incompressible valves.
    • In FlowCoeffCalc, define conversions between different parametrization options based on unit conversion constants.
    • As a consequence of the gain in precision in the conversions, some minor differences can be observed in results. Previous valve models have been moved to a deprecated packages.
  • Fix sign error in logMean function for the case where input arguments have small difference.

Deprecated classes

For result continuity only - updated models remain available at the same path:

  • Modelon.ThermoFluid.Valves.ValveCompressible → Modelon.ThermoFluid.Valves.Deprecated.ValveCompressible
  • Modelon.ThermoFluid.Valves.ValveIncompressible → Modelon.ThermoFluid.Valves.Deprecated.ValveIncompressible

Removed classes

Classes that were duplicates of those in the Modelica Standard Libraray:

  • Modelon.Mechanics.MultiBody.Interfaces.Frame_a → Modelica.Mechanics.MultiBody.Interfaces.Frame_a
  • Modelon.Mechanics.MultiBody.Interfaces.Frame_b → Modelon.Mechanics.MultiBody.Interfaces.Frame_b
  • Modelon.Mechanics.MultiBody.Interfaces.Frame_resolve → Modelon.Mechanics.MultiBody.Interfaces.Frame_resolve

Conversion of User Libraries

User libraries will automatically be converted from version 3.6. These conversions are made using the included conversion script: Modelon/Resources/Scripts/Convert_to_3.7.mos.