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2020.2 Release Notes – Fuel System Library 4.9

Fuel System Library v4.9 is part of Modelon’s 2020.2 release.

New versions of Modelon libraries are sold and distributed directly from Modelon, as well as approved resellers.

New Features

  • Added a new pipe-network example model to illustrate the usage of bend pipes with several variants.
  • Added a new ESDU ejector model. It is a simplified table based model.
  • A conditional fuel content connector is added to the pump. This has to be connected to a tank. Through this connector, fuel relative volume is sensed and given a proper assert warning when the tank nearly becomes empty.
  • A conditional minimum flow controller is added to the mass flow boundary. This can be enabled by setting useMinFlowController in the Advanced tab to true. It sets mass flow to a low value of 1e-6 when the pressure drops below p_t (in Advanced tab).


  • Replaced old environment models System_AFS with a package of new environment models from Modelon base library, including separate models for atmosphere and individual vehicles. This change enables multi-vehicle simulations in a single model with consistent atmosphere definitions.
  • CG computation in the ConvectiveComplexTank is made optional. If enableCG is true, CG is computed else {0,0,0} is returned. By default, enableCG is set to false. It is recommended to have enableCG=false in case it is not required.
  • Merged MuliPressureboundary into PressureBoundary. This included the new PressureBoundary that can handle multiple connections. A conversion script is added to handle the transition in user models.
  • Replaced the pump template model PartialPump with an equivalent from Modelon Base Library
  • Corrected compressibility factor for JetA real-time media
  • Made Re from X Tables conditional, based on the need, in SimplePipeResistance. The default number of points has been reduced to 21 if both wall and lumped frictions are modeled, 15 otherwise.
  • Modified the ejector models to use template structure. All the ejector models and its base class are moved to a top-level Ejectors package.
  • Improved ThirdOrderPower to support an arbitrary number of operating points

Fixed Issues

  • The default value of “p0” (fixed pressure) has been changed to 1 bar from 13 bar in the PressureBoundary.
  • Fixed array mismatch issue in PumpSignal. In PumpCharacteristics.Flow.ThirdOrderFlow, setting q_nom and w_nom default values to be of size 3.
  • In Pump, correcting modifiers of efficiencySpeedCharacteristic to flowmodel.N and flowmodel.q_flow instead of just N and q_flow.
  • Removed obsolete models for rotation free tanks
  • Fixing an issue related to the frame connector in system_FSL which prevented from displaying the correct error diagnostics message.

New Classes

  • Pipes.Experiments.Lumping
  • Pipes.Experiments.Lumping.Information
  • Pipes.Experiments.Lumping.OneBendToOneSegment
  • Pipes.Experiments.Lumping.TwoBendToOneSegment
  • Pipes.Experiments.Lumping.ThreeBendToOneSegement
  • Pipes.Experiments.Lumping.FourBendToOneSegment
  • Pipes.Experiments.Lumping.AllInOneSegment
  • Utilities.PipeResistances.Internal.Table_ReX
  • Utilities.PipeResistances.Internal.XFromRe
  • Ejectors.Experiments.EjectorWorkBench
  • Ejectors.Templates.Default
  • Ejectors.Base.Interfaces.BaseIncompressible
  • Ejectors.Base.ESDU
  • Ejectors.ESDU
  • Utilities.UnitConversion

Removed classes

  • Volumes.Templates.PartialComplexTankRf

Renamed / Restructured classes

  • Sources.MultiPressureBoundary -> FuelSystem.Sources.PressureBoundary
  • Pumps.Base.PartialPump -> Modelon.ThermoFluid.Pumps.Templates.PartialPump
  • Pumps.Base.EjectorBaseIncompressible -> FuelSystem.Ejectors.Base.FrictionCoefficients
  • Pumps.Ejector -> FuelSystem.Ejectors.FrictionCoefficients


  • The DATA_DIR and DIR strings have been removed. It is recommended to use the loadResource function instead which handles file paths in a better way.
  • It has been removed from the following component:
    • SystemBoundary.Examples.FlightDataSource

Conversion of user libraries

Automatic conversion of user libraries from version 4.8 to 4.9 is partially supported using the included conversion script “Convert_to_4.9.mos” located under FuelSystem 4.9\Resources\Scripts.

Read the instructions given in FuelSystem.Information.UsersGuide.Convert_to_4_9 document for the steps for manual conversion.


Fuel System Library 4.9 is based on Modelon Base Library 3.6 and Modelica Standard Library 3.2.3.

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