MBL Version 7.0

Modelon Library 7.0 is part of Modelon's 2026.1 release.

Updated dependency

Modelon Library 7.0 uses the Modelica Standard Library 4.1.0.

New Features

Modelon.Thermofluid

  • The Weather component has been added to the library. This component reads weather data in Excel format, with sample datasets available in Modelon/Resources/WeatherData. In addition, the WeatherDataConversion model has been introduced to help convert raw weather data into a structured and usable dataset format.
  • All heat transfer correlations for two-phase fluids now have the option to filter or "relax" the heat transfer coefficients, which can improve simulation performance for transient scenarios. This option can be enabled either for single components by setting the useRelaxation parameter on the "Advanced" tab of correlation parameters, or for all components in a system by including the Settings_TF component and enabling the useRelaxation parameter there. When enabled, the time constant of heat transfer coefficients can be determined by the parameter "tau". Values in the range of 1 to 10 seconds are recommended.
  • The wall component for heat exchangers, Modelon.ThermoFluid.Solids.DynamicWall, now by default uses two temeprature states per segment so both sides wall surface temperatures are determined by the dynamic states. This can reduce or remove need for iterative equation solving in convection models connected to this component. If connected to another temperature-defining component, it may be necessary to use the wall center temperature as state instead, and that can be done by setting the parameter surfaceState to false.
  • The two-phase capillary flow channel now has the option to initialize to a given pressure and steam quality (X_out), in addition to the combination of pressure and temperature/enthalpy.

Other

  • Added more color map functions for use in visualizers.

Improvements

Several minor corrections to improve Modelica compliance and reduce warnings.

Modelon.ThermoFluid

  • For heat transfer models with non-constant heat transfer coefficient, a limit was indroduced to avoid Nusselt numbers smaller than 1 for low Reynolds numbers.
  • Improved handling of compressor startup from zero speed.
  • The Real output connector of every sensor now has a quantity and unit attribute, to show units when plotting results of sensor outputs.
  • Certain model simplification parameters like "positiveFlow" and "useFixedDensity" now has an annotation to evaluate them at compile time. This make these simplifications more effective in reducing compilation and simulation times when enabled.
  • A change in the source and sink components (MassFlowBoundary & PressureBoundary) allow a small performance improvement when they are used with single-species media.
  • Minor changes to equations in the two-phase flow channel component that reduce risk of simulation slow-down. These changes only affect the transient behavior, not steady-state results.

Modelon.Media

  • Added medium property functions with scalar arguments for liquids. E.g, Liquid.density_pTX can now be called directly without need for the intermediate state record call Liquid.density(Liquid.setState_pTX).

Bug fixes

  • Types of displayed variables in the sensor display component, Modelon.ThermoFluid.Sensors.MultiDisplayVis_phTmdot, were changed from SI-types to Reals to avoid showing incorrect units when plotting these as result variables. This change does not affect the values displayed on the sensor icon.
  • The properties of fully compressible ideal gas, ideal gas with condensed matter and real gas are made sensitive to the system pressure also.

Conversion of User Libraries

User libraries will automatically be converted to version 7.0. These conversions are made using the included conversion script: Modelon/Resources/Scripts/Convert_to_7.0.mos.

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