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-   -   Problem generating a surface mesh (http://www.cfd-online.com/Forums/star-ccm/91246-problem-generating-surface-mesh.html)

danieldiver August 4, 2011 08:33

Problem generating a surface mesh
 
Hello,

I have a problem with my CFD-simulation. I generated a CAD model with Inventor and saved it as an .igs-file. Then I start Star-CCM+ and use the function "import surface mesh" to import my CAD model. I keep all the standard settings. So Star-CCM+ creates a new region with my CAD model. After that I do "split by angle" and define the boundaries (wall, free stream, symmetry).
I select the surface remesher, tetrahedral mesher and the prism layer mesher.
When I'm trying to generate a volume mesh I get an error (no triangles in surface). I tried it several times and it's driving my nuts! I know there's another post about the same error message but that doesn't help me. So I hope someone can help me..

Thanks

Daniel

Maddin August 5, 2011 15:29

Did you made a remesh before ;) Stupid question, but I never had this error.
You also could try to repair/check the surface before, maybe some faults are in.

danieldiver August 6, 2011 04:05

1 Attachment(s)
What do you mean with remesh? Sorry I'm new to cfd..
I did the the surface repair. The attachment shows how the diagnostic looks like. The autorepair erases almost everything...

I'm getting crazy. I need that to pass my cfd course at university!
Or can anyone tell me if there's a way to import x- and y- coordinates (xls-file) from an airfoil profil into star-ccm without using a cad program like inventor?

I'm desprate please help me!

abdul099 August 7, 2011 15:06

Did you import your geometry as part or as region? It makes a huge difference how the error could occur and therefore how to solve it. And when exactly have you done the "split by angle"?

Second: It's not possible to import point coordinates for an airfoil. You can build the geometry with the cad-modeller (v5.02 or later) by hand (very anoying) or import it in any surface format file like iges, parasolid etc.

Third: An imported surface has unsufficient quality for volume meshing and has to be remeshed prior to volume meshing. That's why you've included the surface remesher to the mesh continuum. Hitting the "generate volume mesh" button will start the whole meshing pipeline, including the surface remesher.

danieldiver August 8, 2011 04:02

Quote:

Originally Posted by abdul099 (Post 319203)
Did you import your geometry as part or as region? It makes a huge difference how the error could occur and therefore how to solve it. And when exactly have you done the "split by angle"?

Tried both...
Ok let's try again to explain what I've done :) Let's say import as part.
Next go to surfaces and split by angle, then set region and so on. Trying to generate Volume Mesh -> error: no triangles in surface :(

rwryne August 8, 2011 08:34

Quote:

Originally Posted by danieldiver (Post 319121)
What do you mean with remesh? Sorry I'm new to cfd..
I did the the surface repair. The attachment shows how the diagnostic looks like. The autorepair erases almost everything...

I'm getting crazy. I need that to pass my cfd course at university!
Or can anyone tell me if there's a way to import x- and y- coordinates (xls-file) from an airfoil profil into star-ccm without using a cad program like inventor?

I'm desprate please help me!


Don't use the automatic repair tool! It does crazy things you cannot always control.

More importantly, you do not need to manually repair "close proximity faces" or "poor quality faces". These get fixed by the surface remesher.


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