My mesh is way too refined but still has some bad quality elements. Run does not complete

Hi, everyone!

I am having trouble with a compressible simulation I am working on. It is a simulation of a flow around a rocket body https://www.simscale.com/projects/srocketry/stan_-30-_modificado/. Currently, I have a mesh with 9.3M elements (Mesh 2), with an extra refinment around some specific areas of the rocket that I know are hard to mesh. Analizing the mesh log, this mesh does not seem to match the recommended metrics I found on the docummentation: some elements are really off (Max Skewness = 31; Max Aspect Radio = 601). It does not matter how much I try to refine it, creating other meshes (Mesh 2.1, Mesh 3), it still does not get better. But, since this amount of elements is not big (the average values are quite good), I tried to use some meshes I created to carry the simulation. It did not work and a message asking me to refine the mesh more was showed. The point showed on the message is located at the most refined part of my geometry.

Should I really refine more my mesh, even though it currently has a huge amount of elements and the refinement I did beforehand did not improve its quality? Can someone help me?


Hi there! The link that you shared is not valid ( that content is not here or has been removed). Maybe it is private?

Best regards,
Fillia

Hi! I just fixed it!

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Hi there, I just checked the project and it seems you made a successful run :smiley: Would you like to share what you changed?

Hello! Yes, I made it! But I used only the default mesh - I did not use any refinement, which I think I should do, specially in this type of problem. When it comes to the refinemenets I try to apply, my mesh still has areas areas with huge problems and I do not know what to do. I have generated a lot of meshes but none of them work, besides the default one.

Could you help me? I am starting to think that I am overlooking something.

Thank you in advance :grinning:

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Hello,

Instead of trying to re-mesh the geometry, Iā€™d encourage you to inspect the mesh quality, look for the problematic regions and simply clean the model up in CAD.

I can see a handful of small faces/small gaps which are causing the issues you are having.

Cheers

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Hi Ricardo!

I cleaned up everything I could one the model and the values of the parameters descreased a lot. Thank you so much for your help! However some of them still pretty high and out of the recommended zone.

Here is the link of the project with the new model meshed: [https://www.simscale.com/workbench/?pid=2765674338581600579&mi=spec%3A0c9a7e6a-46cf-423f-9f83-977ed9b0863d%2Cservice%3ASIMULATION%2Cstrategy%3A2]. (I used a smaller enclousure in order to save core hours but, once I can get a good mesh, I will redo it with larger dimensions ). Is there anything else I could do now?

I know that there are some lines that do not seem necessary for the model, but I could not delete them. Also, that small face around the nose cone is something I could work on, but the values for the non-orthogonality are specially high around the fins and I cannot really change those.

One more thing. It seems that a boundary layer is being formed on the external faces of the enclousure of my model, which does not seem to be correct. Is some parameter that I wrongly enabled, perhaps?

Thank you so much for taking time to answer all of my questions! I know that they are too many. Please know that I really apreciate your work! :smiley: