The second update of Flownex® SE for 2020 further expands the possibilities of simulating real-world systems.

Exciting features for this update are a reworked deep solver coupling with Ansys Mechanical for explicit transient co-simulation and automated Nuclear Reactor building script along with many minor enhancements described below.



Ansys Mechanical Coupling

The Ansys Mechanical Flow Solver Coupling component has been improved to allow the simulation of complex 3D conduction and stress in Ansys Mechanical coupled to a flow and heat transfer simulation in Flownex®. This enhancement includes the addition of a deep solver coupling between Flownex® and Ansys Mechanical, allowing data exchange between iterations, full transient co-simulation functionality and unit integration.
Figure 1: Ansys Mechanical Coupling

Nuclear Reactor Builder Scripts

Script Generated Reactor Results

Results in tabular form corresponding to the grid layout of the generated reactor network are written to a text file in the ScriptResults subfolder of the project folder. The tabular results are reported at the end of a steady state run as well as during user specified times and at the end of transient runs. A feature is provided to specify output variables that are reported at every time step. These results are written to a comma separated values (csv) file as a time series residing in the ScriptResults subfolder.

Reactor Generation Script

Various improvements were made to the geometric parameter calculations. Network topology generation for the transitions between different types of reactor zones was extended.

Figure 2: Reactor Generation Script Enhancements



The “Description”, “Minimum” and “Maximum” values have been added to the imported FMU variables. The description will be displayed if it is not blank. Minimum and maximum values will be displayed if they are specified in the FMU and the “Display variable information” property is turned on. A warning is given if the minimum or maximum values for inputs are exceeded.

Figure 3: Description, Minimum and Maximum Values added to Imported FMU’s


The License modules selection have been updated so that it can work for users that do not have write access to their ProgramData folders.


  • Functions to retrieve minimum and maximum temperatures and pressures, as well as critical temperatures and pressures from two-phase fluids via Scripts have been added.
  • Added the ability for Scripts to properly work with lists and Snaps – functions were added that get called in the Script before and after loading and saving Snaps. This gives users flexibility to implement their own Snap saving and loading code.

Composite Heat Transfer Component

The “Area multiplication factor” input for the Composite Heat Transfer (CHT) component has been moved to a separate category to indicate that the input is applied to all surfaces.

Figure 4: Area Multiplication Factor Moved to Separate Category



Fixed the problem where many of the modules were missing when using a borrowed license from the server.

Find Dialog

Fixed the problem where the Find dialog did not open the property page for components on closed pages (it appeared that multi edit did not work).


Line Graph: Removed trailing list separator from the ‘Save As CSV’ file rows.


  • Fixed the Solid Properties script, as the script did not compile correctly due to the enthalpy function that was removed.
  • Fixed the problem where properties for two-phase non condensable mixtures returned zero values as results in the Mixed Fluid Properties Script.

Solver Results

Fixed the problem where the Fluid volume and Fluid mass results in the Flow Solver Results window did not update when it was linked to an Action or displayed on the canvas.

Composite Heat Transfer Component

  • Fixed the problem where an error was issued when connecting the Composite Heat Transfer element to non-pipe flow elements because the roughness could not be determined when the Dittus-Boelter option was specified.
  • Fixed the Composite Heat Transfer element StPr chart option not allowing the user to specify the flow area.
  • Fixed the Reynolds number result on the Composite Heat Transfer element for StPr chart input option not displaying correctly.