System Coupling can be run in either of its user interfaces: its graphical user interface (GUI) or its command-line interface (CLI). Both contexts provide enhanced control over coupled simulation processes, including automatic starts and restarts for participants, the ability to manipulate the System Coupling data model, and an interactive solution workflow. In these contexts, you set up participant physics in the participant's user interface, but perform the coupled analysis — starting the coupling service, loading participants, specifying values for coupling-related analysis settings, and automatically starting participants — in the System Coupling interface. Alternatively, if a coupled analysis setup was exported from Workbench, you can open and execute it in System Coupling's GUI or CLI.
When the coupled analysis is created in System Coupling's GUI or CLI, the coupling workflow
requires a System Coupling participant setup file (.scp) written by Fluent,
as described in Generating a System Coupling Setup File. When a coupled analysis setup has been
exported from Workbench, however, manual generation of the .scp file is not
necessary
For more information, see Using System Coupling's User Interfaces.
To set up a coupled analysis in System Coupling's GUI or CLI, you must generate a System Coupling participant setup (.scp) file.
You can write a .scp file at any time even if you have not specified any System Coupling information by selecting the Write SCP File... ribbon tab item to open the Select File dialog box.
File → Export →
System Coupling... → Write SCP File...
Enter the name of the System Coupling participant setup file and click OK.
You also have the option of automatically writing all available surface and volume information that could be used in a System Coupling run any time you write a case file.
You can enable this at any time by selecting the Auto-write SCP File... ribbon tab item.
File → Export →
System Coupling... → Auto-write SCP
File...
On the dialog box that appears, select Auto-write SCP File with Case File and click OK.
Afterwards, any time you write a case file, a .scp file will also be written.
Important: From Ansys 2020 R1 onward, element data can be used for mapping surface conservative quantities such as surface forces, heat flows, and volumetric heat rates using the following command:
/define/models/system-coupling-settings/use-face-or-element-based-data-transfer?
This enhancement mitigates common mapping issues such as edge effects and profile smearing, resulting in improved mapping accuracy and results.
For cases using .scp files created before Ansys 2020 R1, it is recommended that you generate a new .scp, and use this updated file for the cosimulation run.
In some cases, setup changes are desired or are required to avoid failure of the coupled analysis. When you are running a coupled analysis in System Coupling's GUI or CLI, settings defined under the participant's Execution Control | Fluent Input object allow you to define custom input files. You can use these custom inputs to make changes to Fluent's setup prior to starting an initial or restarted solution.
For more information, see:
The Fluent Input | Option setting defines the type of input files to be used for coupling runs, which in turn determines if/how the inputs may be customized.
The table below provides information on how different Option values affect the input files are used for coupled analysis runs.
Table 49.1: Using the Fluent Input | Option setting to define custom input files
|
Option setting value |
Settings defining input files1 |
System Coupling’s behavior |
Comments | |
|---|---|---|---|---|
|
For initial runs: |
For restart runs: | |||
|
Initial Case File (default) |
The input file defined is defined by the Case File setting. |
Auto-generates a Fluent journal script based on the specified input file. |
Uses the case and data files created by Fluent during the previous run. |
A journal script may be generated and edited for further customization. This is the best option for general workflows. |
|
Initial Case and Data File |
The input files defined are defined by the Case File and Data File settings. |
Auto-generates a Fluent journal script based on the specified input files. |
Uses the case and data files created by Fluent during the previous run. |
Input files can be edited. A journal script may be generated and edited for further customization. |
|
Journal File2 |
The input script is defined by the Journal File setting. |
Uses the specified Fluent journal script. | Uses the specified Fluent journal script. |
Input files can be edited. Additional commands can be added to the Fluent journal script. This option is designed for expert users. |
|
1: When specifying any input file, ensure that the file is valid. System Coupling does not validate input files before the solution is started/restarted. 2: For multiple restarts, ensure that you keep the case and data file values up to date. | ||||
If the Fluent
Input | Option setting is not set to JournalFile, then you can use the GenerateInputFile()
command to generate a Fluent journal script on demand, as shown below:
>>> GenerateInputFile(ParticipantName = 'FLUENT-2', FileName = 'FluentRestart.jou')
When issued, this command generates a journal script that respects the participant's Fluent Input settings and which may be set as the value of the Journal File.
In this way, you can both edit the input file(s) to be used for the coupling run and add further customizations by adding commands to the generated journal script.