Fluids

Fluids

Error during evaluation of an Observable variable in adjoint Fluent

    • rikyfritz95
      Subscriber

      Hello,


      I'm trying to optimize the shape of an airfoil following the tutorial on the "maximization of the lif over drag ratio", but when I try to evaluate the observable (force) it shows me this error:


      999999: mpt_accept: error: accept failed: Invalid argument


      What does it mean? It doesn't happen if I try to evaluate other observables like pressure drop.


      Thanks for your help

    • DrAmine
      Ansys Employee
      Hard to say why. Can you report the force in the usual way?
    • rikyfritz95
      Subscriber

      Thank you for your answer.


      Yes, if I calculate the lift-force in the report definition section Fluent correctly does it. The problem arises when I evaluate the adjoint observable. Here I upload a screenshot of the reported error. After this error Fluent crashes.


       


    • DrAmine
      Ansys Employee

      Which version are you using? Have you tried to evaluate something else?

    • rikyfritz95
      Subscriber

      Yes, if I evaluate other observables like "Pressure-drop" the problem doesn't come. I'm using the Ansys19 version.


       


       

    • DrAmine
      Ansys Employee

      Version 19 is old: I am not sure if there were issues in the past. Attach a screenshot of the Adjoint Observable  definition please.


      I am now using 2019R3/R2 and there is no issues with the tutorial you are mentioning. Alternative: try doing an observable as surface integral of pressure and wall shear stress.

    • rikyfritz95
      Subscriber

      Ok, here I attach the screenshots of the observable definition. Differently from the tutorial I don't use the sine and cosine because I have already rotated the airfoil in the geometry with the angle of 1.5°.  


       



    • DrAmine
      Ansys Employee
      Check if you can do surface integrals as mentioned
    • rikyfritz95
      Subscriber

      I have just tried but It doesn't work in any case. Here I attach the error (no such file or directory)



       


      It evaluates only the pressure drop observable


       



       


       

    • DrAmine
      Ansys Employee
      Okay seems something related to integral based observable. Is it possible to try a newer version?
    • rikyfritz95
      Subscriber

      Yes, probably the university's computers have a recent version. I will try there. Thanks a lot.


      Best regards

    • DrAmine
      Ansys Employee
      Welcome.
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