MBL Version 4.6

Modelon Library 4.6 is part of Modelon���s 2025.1 release.

New Features

Modelon.Electrical.AC

  • Added IdealConductor components (abc and dq0 variants)
  • A new 3-phase ideal transformer model with dq0 representation has been added, featuring configurable Wye or Delta topologies.

Improvements/Changes

Modelon.ThermoFluid

  • The flow channel component for phase-changing fluids, Modelon.ThermoFluid.FlowChannels.DistributedTwoPhase has a correction for fluids at supercritical pressure. The component could previously incorrectly consider the fluid to be in the two-phase region when computing the heat transfer rate in supercritical region. This has been corrected.
  • The pressure drop correlation for two-phase fluids by Friedel, Modelon.ThermoFluid.FlowChannels.PipeResistances.TwoPhase.TwoPhaseFriedel, has been modified in the region of vapor quality between 70 % to 100 % to remove the local maxima in pressure loss that existed there. This modification mitigate oscillating solutions that could occur at high vapor quality for this correlation. For backwards-compatibility there is an alternative implementation of the Friedel corrlation per the publication in Modelon.ThermoFluid.FlowChannels.PipeResistances.TwoPhase.TwoPhaseFriedelWithLaminar. That variant is not recommended for transient fluid system simulation because of risk for oscillating solutions.
  • The computation of Boiling number has been modified in the correlations for evaporating heat transfer Modelon.ThermoFluid.FlowChannels.HeatTransfer.TwoPhase.EvaporationKandlikar and Modelon.ThermoFluid.FlowChannels.HeatTransfer.TwoPhase.EvaporationGungorWinterton. The modification affect the case where a fraction of a control volume is considered to be in evaporating region. In that case the boiling number was previously computed from the control volume average heat flux, including a non-evaporating section. In the updated computation, only the evaporating heat flux is considered. This change mitigate some cases of solutions oscillating at the vapor phase boundary.
  • Parameters regarding the phase freaction stabilizer in Modelon.ThermoFluid.FlowChannels.DistributedTwoPhase have been removed sice the feature is no longer present since MBL 4.5. Modifications of these paraemters in user models will be removed by the supplied conversion script.
  • The DynamicWall component, Modelon.ThermoFluid.Solids.DynamicWall, has a thermal connector 'q' for node temperatures, but heat in this connector was not included in the component energy balance. This has been corrected.
  • Improved parameter dialog of air sources Modelon.ThermoFluid.Sources.AirFlowSource and Modelon.ThermoFluid.Sources.AirPressureSource. Description strings have been improved and less frequently used parameters have been moved to the "Advanced" tab. All parameters are now formally inputs to allow variable expressions. The option to enable all signal input connectors was renamed from "paraOption" to "useInputs". User modifications of this parameter are automatically converted with the conversion script. All other changes are backward compatible and require not conversion of user models.

Modelon.Media

  • All two-phase media had an error that when used in variable-sized volume components, the energy balance was not correct. This has been corrected. Constant-sized volumes are not affected.

Modelon.Blocks

  • Fixed bug in Modelon.Blocks.Sources.VariableSine that gave an output signal with the wrong frequency.

Modelon.Utilities.Optimization

  • Added support for Dynamic optimization using CasADi.

Conversion of User Libraries

User libraries will automatically be converted from version 4.6. These conversions are made using the included conversion script: Modelon/Resources/Scripts/Convert_to_4.6.mos.