JPL Version 2.7

JetPropulsion Library 2.7 is part of Modelon's 2024.1 release.

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

New features

  • Added moist air variants of natural gas with combustion media packages with lumped dry air and an air mixture using NASA7 properties.
  • Variable geometry nozzle capabilities for both throat and exit area. This is demonstrated in Experiments.MixedTurbofan.VariableNozzle
  • More accurate efficiency correction models for compressors and turbines. Compute the efficiency with correlations taking reynolds number index, entry into service, size (corrected flow) and stage loading into account. They use of these are demonstrated in the new multi-point experiment model Turboprop.MultipointWithEfficiencyCorrection


  • Added support for the new Moist Air media with the JetPropulsion.Utilities.Adapters.Adapter. MoistAir and MoistAirMixture variants with Kerosene or NaturalGas can be adapted to a compatible media package for use with Modelon Base Library components. See the adapter documentation for more details.
  • Mass estimate model JetPropulsion.Basic.MassEstimate.Nozzles.Onat1979 supports axisymmetric nozzle core.
  • Mass estimate model JetPropulsion.Basic.MassEstimate.Burners.Onat1979 supports for automatic computation of geometry based on neighbouring components, as well as manual modification of flow velocity.
  • Mass estimate model JetPropulsion.Basic.MassEstimate.Ducts.Onat1979Kaiser2020 support automatic computation of geometry based on neighbouring components, if Kaiser2020 option is selected.

Corrected nozzle exit station numbers

  • core nozzle exit: 8 → 9
  • core nozzle exit ideal: 8id → 9id
  • bypass nozzle exit: 18 → 19
  • bypass nozzle exit ideal: 18id → 19id

Fixed Issues

  • Correcting temperature bounds for Walsh and Fletcher polynomials based on reference (200K - 2200K, which is broader than shown in the reference with 2000K). See the &rsquoConversion of user libraries&rsquo section for more information
  • Corrected the computation of the substance mass fractions downstream of the mixer.
  • Corrected computation for compressor geometry change between outlet and inlet in JetPropulsion.Basic.MassEstimate.Compressors.Onat1979Axial

Library structure changes

New classes

  • JetPropulsion.Media.PreDefined.MoistAirMixtureKerosene
  • JetPropulsion.Utilities.Adapters.MediaMBL.MoistAirMixtureKerosene
  • JetPropulsion.Media.PreDefined.MoistAirNaturalGas
  • JetPropulsion.Media.PreDefined.MoistAirMixtureNaturalGas
  • JetPropulsion.Utilities.Adapters.MediaMBL.MoistAirNaturalGas
  • JetPropulsion.Utilities.Adapters.MediaMBL.MoistAirMixtureNaturalGas
  • JetPropulsion.Basic.Nozzles.Experiments.VariableGeometry
  • JetPropulsion.Basic.Nozzles.VariableGeometry
  • JetPropulsion.Experiments.MixedTurbofan.VariableNozzle
  • JetPropulsion.CyclePerformance.Control.Nozzle.ARFromAthqthDes_parabolic
  • JetPropulsion.CyclePerformance.Control.Nozzle.AthqthDesFromPr
  • JetPropulsion.CyclePerformance.Control.Nozzle.AthqthDesFromRline
  • JetPropulsion.Experiments.Turboprop.MultipointWithEfficiencyCorrection
  • JetPropulsion.CyclePerformance.Control.Boundary.FlowRateFromBurnerOutletTempPowerScheduled
  • JetPropulsion.CyclePerformance.Control.Boundary.FlowRateFromTurbineTemp
  • JetPropulsion.CyclePerformance.Control.Burner.FarFromTotalPower
  • JetPropulsion.CyclePerformance.Control.Compressor.OverallPressureRatioPowerScheduled
  • JetPropulsion.Basic.Turbines.EfficiencyCorrection
  • JetPropulsion.Basic.Compressors.EfficiencyCorrection
  • JetPropulsion.Basic.Turbines.Correlations.EfficiencyCorrection
  • JetPropulsion.Basic.Compressors.Correlations.EfficiencyCorrection.Examples
  • JetPropulsion.Basic.Compressors.Correlations.EfficiencyCorrection.Samuelsson2015
  • JetPropulsion.Basic.Compressors.Correlations.EfficiencyCorrection.Samuelsson2015Polynomial

Moved classes

  • JetPropulsion.Basic.MassEstimate.Ducts.Onat1979 → JetPropulsion.Basic.MassEstimate.Ducts.Onat1979Kaiser2020

Conversion of user libraries

Due to the change with limits described in ’Fixed issues’ the user may see the following message:

Error: The following error was detected at time: 0

The arguments x_min and x_max to OneNonLinearEquation.solve(..) do not bracket the root of the single non-linear equation:

x_min = 1

x_max = 2200

This means that the results are unphysical and outside of the media property bounds. The media properties do not allow temperatures beyond 2200K (and they are already extrapolated from 2000K). It is therefore required to either change the model to stay within the bounds or switch to another media model like the ones based on NASA7: NasaAirMixtureHydrogenWater or NasaCarbonOxidesAndOxygen

Automatic conversion of user libraries from version 2.6 to 2.7 is partially supported using the included conversion script "Convert_to_2.7.mos" located under JetPropulsion 2.7\\Resources\\Scripts.


JetPropulsion 2.7 is based on Modelon Base Library 4.4 and Modelica Standard Library 4.0.0.