Fluids

Fluids

Fluent- increasing in the back pressure leading to divergence

    • ravitejagonnabathula007
      Subscriber

      Dear CFD buddies,


      I'm simulating a supersonic inlet by increasing the back pressure ratio. Till the the back pressure ratio of 4 at the interval of 1 I was able to generate results. When I'm simulating for back pressure ratio of 5 I couldn't solve and AMG solver is being detected.

      Tried refining the mesh- didn't worked

      Settings:
      altitude30km (corresponding P, T values)
      Mach :2.18
      Desnity based solver
      Spalart–Allmaras turbulence model
      Explicit solver
      courant number -0.5

      Hope I could find the solution.
      All suggestions are accepted

    • Keyur Kanade
      Ansys Employee

      With Mach 2.18, you can use pressure based solver. 


      Use ideal law for density. 


      Please try refined hex or tet with prisms mesh. 


      Check mesh quality. Is it 2D or 3D?


      Regards,


      Keyur


       


      If this helps, please mark this post as 'Is Solution' to help others.


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    • ravitejagonnabathula007
      Subscriber

      its is 2D. ill try with pressure based solver and update the status

    • ravitejagonnabathula007
      Subscriber

      I tried solving with pressure based solver, but it diverged nearly at 1000 iterations.


      can u give me some more suggestions to proceed further?

    • Rob
      Ansys Employee

      Check mesh resolution around the shock: chances are the pressure gradients are high and you need to refine the mesh. 

    • Keyur Kanade
      Ansys Employee

      Please check by refining the mesh. 
      Also please check mesh quality. 


      With student version you have limit of 512K cells. 


      So you may need to consider to reduce problem size as well. You may check symmetry in the model. 


      Regards,


      Keyur


       


      If this helps, please mark this post as 'Is Solution' to help others.


      Guidelines on the Student Community


      How to access ANSYS help links


       

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