2-way system coupling error

ningxinningxin Member Posts: 2


I'm trying to simulate a fluid-structure interaction with Fluent and Transient Structural. When I start solving the system coupling, the error message below appears:

Update failed for the Solution component in System Coupling.  The coupling service failed to start.

Association: C3.

Can someone tell me where the problem is?



  • Abbu2uAbbu2u Posts: 2Member

    Hi, I am also getting same error while solving two way coupled fsi so please let us know what should do in this case.

    Thank you



  • KremellaKremella Posts: 2,485Admin


    How are you setting up your model? What are your Data Transfer? Have you attempted to start the Mechanical and Fluent simulations separately? Did you receive any error message when you run these simulations separately?

    Thank you.


  • damladrmsdamladrms Posts: 6Member

    Hi Kremella, I have getting same error. I used both static structural+steady fluent and transient structural+transient fluent, but I have got same error. I have tried complete analysis in structural and fluent, they work.

    Additionaly, I have got these explanations in soluion information:


    | Warnings were found during data model validation.              |


    | Restart output is only requested at last step. To enable restarts from   |

    |   intermediate points, use another 'OutputControl' option.        |

    | Participant CouplingParticipant:Solution 1 has the ExecutionControl     |

    |   'Option' set to 'ExternallyManaged'. System Coupling will not control  |

    |   the startup/shutdown behavior of this participant.           |

    | Participant CouplingParticipant:Solution has the ExecutionControl 'Option' |

    |   set to 'ExternallyManaged'. System Coupling will not control the    |

    |   startup/shutdown behavior of this participant.             |


    Awaiting connections from coupling participants...


    | "System coupling solution stopped before all participants connected. A   |

    | solver failure occurred during the run in the Static Structural system"

    Do u have any idea about that problem?

    Thank you.


  • SteveSteve Posts: 153Forum Coordinator

    Hi @damladrms , @Abbu2u,

    I recommend following these steps when encountering problems with System Coupling.

    1. When running System Coupling and it stops running, the first thing to do is examine the output files for each solver to look for clues to what happened. For Fluent, look at the transcript .trn file. For Mechanical, look at the .out file. Also, look at the System Coupling log file, .scl.
    2. I recommend going over this tutorial in the Ansys documentation that shows a 2-way FSI simulation with Fluent and Mechanical. https://ansyshelp.ansys.com/account/secured?returnurl=/Views/Secured/corp/v202/en/sysc_tut/sysc_tut_oscplate_wb_fluent.html, System Coupling Tutorials \\ Tutorials with Workbench-Setup Workflows \\ Tutorials with Workbench Setup and Execution \\ Oscillating Plate FSI with Fluent and Mechanical
    3. You can also look at the following for the same tutorial but run with the System Coupling GUI or Command Line Interface that is run outside of Workbench. The new System Coupling GUI (run outside of Workbench) is available by searching for "System Coupling 2019R3 (or newer)" in the Start menu. https://ansyshelp.ansys.com/account/secured?returnurl=/Views/Secured/corp/v202/en/sysc_tut/sysc_tut_oscplate_cli_fluent.html, System Coupling Tutorials \\ Tutorials with Command-Line Interface (CLI) Workflows \\ Oscillating Plate FSI with Fluent and Mechanical
    4. It is very important to build up the FSI simulation in stages as opposed to setting up the 2-way FSI right at the start. This document "Best Practices for Coupled Fluid-Structure Interaction (FSI)" describes this process and is available here: https://ansyshelp.ansys.com/account/secured?returnurl=/Views/Secured/corp/v202/en/sysc_ug/sysc_bestpractices_fsi.html, System Coupling User's Guide \\ Best Practices for System Coupling \\ Best Practices for Coupled Fluid-Structure Interaction (FSI)


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