FLOWNEX SE 8.9.1 (2018 – UPDATE 1)

FLOWNEX SE 8.9.1 (2018 – UPDATE 1)

We have launched our latest update of Flownex® SE for 2018.

Some of our major enhancements is adding a thermostat and thermostat bypass component, scale drawing measurements, liquid mixtures and more.



Thermostat & Thermostat Bypass

Fig. 1 - Thermostat and Thermostat Bypass
Thermostat and Thermostat Bypass components were added to the Flownex® component library. Thermostats are required in systems that control the heating or cooling of the working fluid close to the desired temperature. This component is typically found in engine cooling systems or airconditioning of buildings. The component level behaviour is therefore similar to a valve that will change its opening as a function of temperature.
A typical thermostat has two flow paths, namely the primary flow path and the bypass flow path, however there are cases without a bypass, and therefore Flownex® allows the modelling of a Thermostat with and without a Thermostat bypass. The opening of the Thermostat is dependent on the inlet static temperature and specified as a chart. The opening of the Thermostat Bypass is obtained from the opening of the Thermostat, also defined by means of a chart. The secondary loss for both the Thermostat and Thermostat Bypass as a function of their respective openings are calculated from the user-defined charts for secondary loss versus opening.
Fig. 2 - Close-loop network with a Thermostat and Thermostat Bypass

Scale Drawing Measurements

The scale drawing functionality has been expanded. A scale drawing ribbon was added to the toolbar with all the scale drawing related functionality.

Fig. 3 - Scale Drawing Ribbon Bar

The user can specify the scale and coordinate system of an imported drawing with two known coordinates on the drawing canvas. This allows the drawing origin to be away from the zero-point on the axis and also simplifies specifying the scale. The drawing scale and coordinate system can be changed at any time and the components will be scaled accordingly.

Fig. 4 - Generate Scale Drawing dialog

Point and line measurements can be drawn on top of the imported picture. The line will determine the correct lengths and coordinates from the scale and coordinate system of the imported drawing.

Fig. 5 - Adding a point or line measurement

The coordinates of the points and length of each line can be connected to any input fields on components. They are connected without data transfer links to avoid cluttering the drawing canvas.

Fig. 6 - Input property link to a measurement on the drawing canvas

Fields associated with the measurements are greyed out. Moving the points or lines will update the coordinates and lengths while keeping the associated fields updated.

Fig. 7 - Input property greyed out when linked to a measurement

The point and line measurements or the components and links drawn on top of a scale drawing picture can be hidden and shown when required with the buttons on the Scale Drawings ribbon tab. The opacity of the background picture can be changed to make it easy to see the measurements on the drawing. The opacity slider on the toolbar is used for this.

Global Parameter Displays on Drawing Canvas

Right-clicking on any property in the input or result grid will display a context menu with a new option called “Display on Canvas”. This allows the user to choose the location where to display this property for all components of the same type. The same context menu of the relevant property on the property grid is used to remove what is displayed on the Drawing canvas.

Fig. 8 - Adding an input or result property using the right-click context menu

In the configuration screen, the user can change the advanced configuration options like the number of significant digits, or whether the caption should be displayed.

Fig. 9 - Configuration screen for the displayed parameters

Script Debugging

The Scripts can be debugged if a debugger is installed on the computer. Visual Studio is recommended for debugging. The Debug button is located on the Script editor.

Fig. 10 - Script editor with the added debugging

After clicking the Debug button then the user will be prompted to select which debugger to use.

Fig. 11 - Prompt to select appropriate debugger

A breakpoint can be placed in the relevant function requiring debugging and the run button can be pressed in the debugger to continue. The debugger will break as soon as your chosen line of code is hit.

Fig. 12 - Breakpoint added to the debugger

Liquid Mixtures

The ability to specify a fluid mixture consisting of multiple liquids was added. The user can select various liquids as pure fluid components in a fluid. The mass fractions for each component are specified similarly for gas mixtures. Flownex® will calculate the mixture thermodynamic properties and the user can specify the mixing rules for the transport properties (viscosity and conductivity) by selecting one of the pre-defined mixing rules or coding a script for custom mixing rules. The mixture will be treated as a single-phase liquid in the Flownex® solver. A Help button was added to direct the user to the appropriate location in the User Manual discussing the mixed fluid theory.
Fig. 13 - Multiple liquid mixture specified in Flownex


Specify Drawing Grid Spacing

The size of the grid on the drawing canvas can be changed on the page inputs. To access the page inputs right-click on a page and choose “Edit Page” on the context menu.

Fig. 14 - Specifying drawing grid spacing

Change Location of Identifier and Description Text

The location of the display can be changed in the project settings under “Drawing Text Settings”.

Fig. 15 - Changing the location of the Identifier and Discription

Added Button to Copy Used Data References to Project Database

A button was added enabling the user to copy all the charts and lookup tables from the databases located in the project to the project database. This is useful when using a company database and it is necessary to send a project to another user that does not have that database.

Fig. 16 - Copy the Data Reference to Project Database

Added Confrim Delete Dialogon Data References & Categories

The user will be asked for confirmation before deleting a data references to prevent accidental deletions.

Fig. 17 - Confirmation dialog before deleting a data reference

Master Database Location

The location for the built-in master database that ships as part of the Flownex® installation was changed. The name for the database folder is now “Master” (it was previously in a folder called “Project” in the installation folder).

Nuclear Reactor

Added friction factor and flow area to Detailed Reactor Output file.


The Python resource files have been updated. Firstly, a getting started guide has been added to assist new users with installing Python and installing the required libraries for using the Flownex API. Another example has also been added to show how Python can be used to automatically build a network from a CSV-file using the API. Furthermore, the Flownex.py file has been updated to automatically determine your Flownex install directly from the registry entries created when Flownex is installed.


The Cooling orifice was removed and will be replaced with a Nozzle in the existing networks.


Drawing Canvas

  • Fixed the problem when pasting a component the component was not always placed at the location where the preview showed.
  • Changed the Ctrl+Drag+Copy mechanism to work the same way as other software.
  • Fixed the problem where background image selection for graphs did not work.
  • Fixed the problem when first Copy-Paste and then undoing of components on geometries left viewless components in the project.

Property Grid

  • 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).


  • Fixed the problem when specifying an end time on the main scenario in actions causing the user interface to freeze.

Nuclear Reactor

  • Fixed the problem where the solid material selection drop down box freezes in the general fuel zone in the Nuclear reactor component.
  • Fixed the problem when specifying fractions in the general fuel zone where double precision numbers did not exactly add up to 1.0 for Total solid fraction and Total heat fraction.
  • Fixed the problems when the solution produced NaN results for moderator temperature and reactivity when moderator fraction is set to 0.0.

Flow Solver

  • Fixed convergence criteria for the Two-phase tank component where solving seemed to have converged whilst still solving to converge the Two-phase tank component.
  • Fixed the problem causing the Flow resistance component not to solve when the initial pressure drop is zero.
  • Fixed the problem with the loading of snaps for non-circular pipes and number in parallel not set to unity.
  • Fixed the problem with liquid-gas mixtures during transients with Two-phase tank component not solving.
  • Added a mass fraction relaxation parameter to solver inputs for liquid-gas mixtures.

Flow Solver Components

  • Fixed an error in the Reynolds number calculation for Orifice in pipe transition component.
  • Fixed the problem where the mass fraction boundaries are not correctly applied when specified in the first time step of a transient when changing setting from mass source fraction to mass fraction boundary.
  • Added a warning when the British standard orifice’s solution is in the two-phase regime.
  • Added a warning when two-phase conditions exist at an element outlet when exit temperature is specified.

Download full release notes here.

FLOWNEX SE 9.8.0 (2018)

FLOWNEX SE 8.9.0 (2018)

We have launched our latest Flownex® SE 2018 release. As always we focus on bringing you simulation software that will improve results, reduce solving time and give you control over the outcomes.

The biggest addition is the expanded fluid models, which now includes the capability to model a “liquid-gas” mixture. We have also given attention to FMI support, added functionality that clearly indicates solving disabled components and links, as well as updating the CFX Generic Interface Coupling to reduce solving time.




Liquid Gas Mixtures

Flownex® has expanded the fluid models to include a “liquid-gas” fluid model capable of modelling a multi-component two-phase mixture.
Fig. 1 - Bearing Sump - Typical Application for a Liquid-Gas Mixture Model
The new “liquid-gas” fluid model in Flownex® is ideal for the accurate prediction of the flow regimes and pressure drop of air-oil flow in many industrial applications. For example, in aero-engines, air and lubrication oil are mixed in a bearing chamber, which is subsequently drained by a scavenging system comprising of a pump and piping system where the air and oil are separated. The complex nature of this two-phase flow, characterized by turbulence, a deformable phase interface, phase interaction, phase slip, and compressibility of the gas phase makes the mixture difficult to analyse and therefore makes these lubrication systems difficult to simulate. To overcome these difficulties, Flownex® has added an updated set of governing equations to describe the interaction of the phases. Additional pressure drop and flow regime correlations have also been added to provide a commercial solution to the design of pressurised lubrication systems.
Fig. 2 - Gas & Liquid Mixture Specified in Flownex

FMI Support

The ability has been added for Flownex® to export a network as a FMU (Functional Mockup Unit).
Fig. 3 - FMI (Functional Mock-up Interface)

This FMU is FMI 2.0 standard compliant and can be used for co-simulations in any FMI 2.0 co-simulation master application.

Fig. 4 - FMU Configurations Button available in the Configuration Tab
The FMU Configurations is described in more detail in Chapter 14 of the Flownex® General User Manual.

Disabled Solving

All solving disabled components and links are now clearly indicated with a red cross on the drawing canvas, as seen in Figure 5.

Fig. 5 - Disabled Solving Components

Data Transfer Links

An error or warning is now given when data transfer encounters NAN or infinity. There is a setting in the project settings where this can be controlled, as seen in Figure 6. There is also an option to pause simulation if error or warning occurs during data.

Fig. 6 - Data Transfer Settings in Edit Settings Dialog

Global Parameters

A list of current global parameters will now pop up when a user starts to type a global parameter in the property grid. To see the list, start typing the “$” symbol in a field in the property grid.

Fig. 7 - Global Parameters List

License Queueing

The capability was added to queue for a license. License queueing can be enabled from the Help ribbon, or from a button on the License error dialog.

Fig. 8 - License Queueing Capability added to Flownex

CFX Generic Interface Coupling

The CFX Generic Interface Coupling component has been updated to reduce solving time. The previous component passed boundary conditions to the CFX solver, started the CFX solver, waited for the CFX solver results and used the results together with expressions in CFD-Post (CFX post processing tool) to return updated boundary conditions. The CFX solver and CFD-Post tools therefore started and stopped each time where information was transferred. The new coupling allows the Flownex® and ANSYS CFX solvers to run uninterruptedly while updating variables between the environments based on User Fortran routines. CFD-Post is not used to retrieve the updated boundary conditions from the CFX solver results. The CFX solver will not be started and stopped every time information is transferred. This removes the overhead in the CFX processing and cuts the solving time dramatically.

Training Course

The Flownex® basic training course that is available on the Flownex® website for registered users was put onto the start page of Flownex®. The links on the page link to Youtube videos, so users need to have access to Youtube to view them. In countries without access users can view them by registering on the Flownex® website.
Fig. 9 - Training Course



Added a dialog for the user to confirm if components should be deleted from the project or an external database.


Added a function to NetworkBuilder so that the user can specify which fiber to use when connecting components/compounds with many fibers.

Convection Component

Added the capability for the user to specify a script defined heat transfer coefficient to the Convection element. The input options were changed to be more in line with other places that convection is specified.

Fig. 10 - Convection Element with Script Defined Heat Transfer Coefficient Input

Finned Tube Heat Exchanger

The Wall Heat Transfer Coefficient has been changed to a dynamic input, so that this input can be changed during a transient simulation, as seen in Figure 10.

Fig. 11 - Wall Heat Transfer Coefficient of the Finned-Tube Heat Exchanger

Nuclear Reactor

  • Added Flow element maximum velocity to the Reactor as a result.
  • Show velocity in x and y direction on nodes in the general fuel.
  • Show generated heat on flow nodes.

Nozzle & Rotating Nozzle

  • Added Flow element maximum velocity to the Reactor as a result.
  • Show velocity in x and y direction on nodes in the general fuel.
  • Show generated heat on flow nodes.


Global Parameters

  • Fixed the problem where the Global Parameter name could not be edited.
  • Fixed the problem where non-SI units caused wrong values to be used initially when creating Global Parameters from the Property Grid.

Property Grid

  • Fixed the problem where the go-to disabler on disabled property grid properties showed only one data transfer link, even when many properties are disabled by different data transfer links.

Excel Component

  • The automatic linking of properties to cells in the Excel component by dragging and dropping them on Excel cells did not work and has been fixed.

Grid Editor

  • Fixed the problem where the drop downs caused errors in the Grid Editor when showing them and moving over them.

Component Defaults

  • Fixed the problem where the drop downs caused errors in the Grid Editor when showing them and moving over them.

Discharge Coefficient On Nozzles

  • Fixed discharge coefficient (Cd) calculation for chamfered inlets.

Rotating Cavities

  • Fixed incorrect indexing used in the solver under some conditions for the Rotor-Rotor and Rotor-Stator cavities.

Download full release notes here.