Overset Mesh and define_profile UDF macro

MawenMawen Member
edited November 19 in Fluids


Hope everyone is doing well in these strange times!

I am simulating a flexible foil in Fluent via describing the surface nodes motion using the define_profile macro in an UDF.

My question is, it works fine with a "normal" mesh setup but does not when using overset mesh (please see attached image). Is it generally OK to use this macro together with overset mesh and what could be the reason for this error? I already tried quite a few things but currently cannot figure it out.

Many thanks



  • RobRob UKForum Coordinator

    It should work. Looking at your model the back ground mesh looks very coarse so it could be linked to that. How many orphan cells are you getting? However, as you're deforming the mesh too overset has no benefit over moving deforming the zone around the airfoil. If the airfoil was fixed in shape but moving (eg boat bobbing on the water surface or something falling off an aeroplane) then overset can be better.

  • MawenMawen Member
    edited November 20

    Hi Rob

    Thanks for the fast reply!

    My idea is to move the overlying mesh across the underlying mesh with another macro, CG_motion or define_profile.

    I will try a finger mesh just now and share results, thanks!

  • RobRob UKForum Coordinator

    I'd suggest you either move the circle body above but don't deform the shape; or deform the shape within the circle without the overset (ie split the circle out).

  • Hi Rob

    Thanks again! The refinement didnt improve the result. For all meshes there are no orphan cells.

    I think my general idea wouldn't work, as when I assign the dynamic mesh, the circle cannot be deforming (define_profile) and rigid body (CG_motion) at the same time.

    Anyway, still not sure why the deformation doesnt work for the overset, but will try something else than overset next.

    Thanks for the help

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