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 4.9ResourcesScripts.

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.