General Mechanical

General Mechanical

2 way Fluid strcuture Interaction ( Blade excitation using Air jets )

    • mohammedlaminemekhalfia
      Subscriber

      Dear Ansys users.


      Well, I am working on a 3D fluid-structure interaction problem, my problem consist of a 3D twisted blade excited by air jets though a pipe of 8 mm diameter ( a step function of 1 bar amplitude) using a profile


      The workbench is set to (transient + fluent) workstation as the parameters are as follow
      ---- Transient settings:
       
      for the fixed suppot:


      System coupling interface


      ------- Fluent side








      -------- SC parameters

      Duration control: 2s

      Step control:  0.0005 time step size

      Coupling Interface: One set to fluent  at blade_wall (System coupling region)

      Two  set to transient system coupling region

      Data transfer  Dispolacement/force

      Relaxation factor to 0.5

      Convergence target 0.01

      The questions

      •  after finishing the simulation , I plot the displacement versus time at the tip of the blade


      I was expecting a step, but the ramp at the edge, this I could not find reason why!!!!
      The following was ploted from 1 way FSI using external data:

      •  The second issue, when I used system coupling GUI and launch the solution, the number of folvers set only to 1 which cause a big processing time even that I reset the values mannually to a higher solver numbers both in transient and fluent and the number of licences is available, yet the problem occurs
    • Rahul Mule
      Ansys Employee

      Hi ,

      Try with the end time step input same as in System Coupling setup and set Autotime Stepping to Off, Define by Substeps, No. of substeps = 1.

      And also check in SyC setup under Data Transfer whether Ramping option set to linear for either Force/Displacement data transfer.

      Hope this helps you.!

      Regards

      Rahul

    • mohammedlaminemekhalfia
      Subscriber

      @Rahul Mule Thanks for the reply.

      I made the following change:

      The end time step input same as in System Coupling setup

      Autotime Stepping to Off

      Define by Substeps

      No. of substeps = 1

      Ramping option set to linear for both Force/Displacement data transfer

       

    • Rahul Mule
      Ansys Employee

      Hi, 

      Try keeping other settings as it is and change the ramping option to none. 

      Regards,

      • mohammedlaminemekhalfia
        Subscriber

        okey, also I have problem in launching the SYSTEM COUPLING GUI using the  Command line. I could not register the project in a Command line format as when exporting it does not give the adequate format to export under it which does not permit changing the number of process and this lead to a huge compuational time just for small problem like that.

        I will try to perform it and return to you with updates

        Thanks a lot

    • Rahul Mule
      Ansys Employee

      Hi Mohammed,

      Please refer Using the System Coupling Command-Line Interface (CLI) (ansys.com) to launch System Coupling using the command line.

      Hope this helps you!!

      Regards,

       

      • mohammedlaminemekhalfia
        Subscriber

        I am using ANSYS 2021 R1 unfortunatly the refered resource does adapt to my work, I went through the  guide but nothing work

    • Rahul Mule
      Ansys Employee

      Hi, 

      You can also find the help for 2021 R1. Please refer for 2021R1 version. Getting Help in the System Coupling CLI (ansys.com)

      Please share the commands that you are using.

      Regards,

      • mohammedlaminemekhalfia
        Subscriber

        I reperformed the analysis with the same parameters except the I put the ramping option to non but still the result did not change.

         

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