SimScale CAE Forum

Divergence in incompressible analysis around a vehicle

Can anyone help me with this.I already refined the problematic part in my mesh but it is still diverging.Im performing Incompressible fluid simulation to a car.After running the simulation,this statement appeared
“Gauge pressure field started diverging. Please check the mesh quality near the reported location and try refining the mesh. If the problem occured near a boundary, please check the boundary conditions. In case of doubt, please ask for assistance via our support chat”

Hi there, can you add the link to the project please? :slight_smile:
Also, when divergence happens, please check these guides:

Best regards,
Fillia

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Hi Filliasorry for the late reply.This is the link for my project Numerical Investigation | SimScale
Im getting a really large drag coefficient and Im not really sure why.I already try to refine the mesh around the car but it still didnt work.What should I do to solve this?I think Im missing something but I really cant identify what it is.

Dear @rian_garcia , here are my comments:

Do use a structured mesh (hex-dominant). Do not use the automatic mesher for this particular flow problem. By the way, you have too many grid elements to start from. Bad mesh + fine mesh = high stiffness in the resolved matrix and because you have a moving wall, that’s immediate divergence.

Study the excellent SimScale tutorials on how to set a parametric hex-dominant mesh, start with around 500K elements and without the moving wall. Once the simulation runs well, activate the moving wall. Afterwards, increase / refine the mesh as required. As a further improvement, document yourself (again with SimScale material) about the freeStream boundary. The car is not confined to a square tunnel, right?

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Noted.Yes I’m not simulating a car in a wind tunnel but Im considering it.Thanks jairogut

So, did it work?

Sorry for the late reply jairogut.I cant fully say that it works but compared to my simulation last time,it became better.Right now im having a problem with my boundary layer.

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