classVersion_1_4_0

Version 1.4.0 (August 2026)

Extends from Modelica.Icons.ReleaseNotes.

Information

Version 1.4.0 is a minor release of the DLR Thermofluid Stream Library. It introduces the new ThermofluidStream.Idealized package, new flow-control functionality and major improvements to sensors, valves, heat exchangers and examples.

No conversion script is required. Existing models may nevertheless require parameter adjustments because of changed defaults and new validation checks.

Highlights

  • Added the new ThermofluidStream.Idealized package for simplified thermodynamic process and cycle modeling.
  • Added ThreeWayValve; the previous Switch model is now obsolete.
  • Substantially improved sensor icons, connector placement, dynamic value displays, numerical formatting and selectable display units.
  • Improved valve diagnostics and added validation of standardized flow-coefficient reference values.
  • Improved heat-exchanger icons, assertions and OpenModelica compatibility.
  • Updated the SimpleAirCycle example and several media, pump and heat-exchanger examples.

New functionality

Idealized thermodynamic modeling

The new ThermofluidStream.Idealized package provides boundaries, thermofluid components, energy-flow models, idealized thermodynamic processes, topology models, utilities, examples and tests for conceptual thermodynamic system analysis.

Dynamic icons for visibility in Dymola and OpenModelica.

Three-way valve

A new ThreeWayValve based on BasicControlValve has been added. It provides parameterization similar to the previous Switch model and includes a graphical indication of the valve position. The previous Switch model remains available but is marked obsolete.

Improvements and fixes

Sensors
  • Improved icons, connector placement, numerical formatting and dynamic measurement-value displays.
  • Added display units for specific enthalpy, specific entropy, molar mass, enthalpy flow and entropy flow.
  • Corrected the mass-flow output unit in MultiSensor_Tpm.
Flow control
  • Added visual indications to MCV and PCV when the requested set point cannot be reached.
  • Assertion messages now identify the affected component instance.
  • Deprecated the Cvs_UK flow-coefficient option while retaining it for compatibility.
  • Added validation of dp_ref and rho_ref when standardized flow coefficients are used.
  • Improved valve icon compatibility with OpenModelica.
Heat exchangers
  • Improved connector handling and OpenModelica compatibility of discretized heat exchangers.
  • Redesigned counter-flow and cross-flow heat-exchanger icons.
  • Corrected mass-flow assertions in PartialDiscretizedHEX.
Test and examples
  • Updated media, pump and heat-exchanger examples.
  • Updated SimpleAirCycle for a regional-aircraft cruise operating point and added additional sensor and cooling-power displays.

Migration notes

Isenthalpic pressure-drop enforcement

Only for the ones using the idealized package before: The default value of ThermofluidStream.Idealized.Processes.Isenthalpic.enforcePressureDrop has changed from true to false to improve numerical robustness. Models requiring the previous behavior must explicitly set: 

enforcePressureDrop = true
Valve reference values

When using Kvs, Cvs_US or Cvs_UK, the following reference values must not be modified:

  • dp_ref = 1 bar
  • rho_ref = 1000 kg/m3

New assertions detect modified reference values because these currently lead to incorrect model behavior. Reducing the corresponding assertion level to a warning does not correct an invalid parameterization.

Deprecated and obsolete functionality
  • ThermofluidStream.FlowControl.Switch is obsolete; use ThreeWayValve.
  • ThermofluidStream.Utilities.RealVector is obsolete.
  • The Cvs_UK flow-coefficient option is deprecated.

These elements have not been removed, so existing models remain loadable.