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-   -   [cfMesh] overlapping problem using cfMesh v1.1.1 (https://www.cfd-online.com/Forums/openfoam-community-contributions/162067-overlapping-problem-using-cfmesh-v1-1-1-a.html)

pici November 2, 2015 13:03

overlapping problem using cfMesh v1.1.1
 
Hi to everybody,
I'm using a.s.a.p cfMesh (instead of snappyHexMesh), because it is infinitely more friendly then oF.
But, when I must import CAD geometry (for complex parts), some time I receive this error message, when I check trisurface .fms mesh, using checkSurfaceMesh utility.

Code:

Found overlapping parts in the surface mesh!!
This causes problems to the automatic refinement procedure. Please avoid using the minCellSize option.

I need to explain my method:
- I import a step file in Salomé (rel 7.6.0)
- I create an opportune set of face groups and, using extractFeatureEdges.py, also the FeatureEdge group
- I create a 2D mesh (only on surfaces) ad I add elements group by geometry
- finally, I export the just created mesh in .fms file, using salomeTriSurf.py utility.
Before to start final meshing process, I check this trimesh using checkSurfaceMesh and very often I receive the message already reported.
It never happens when I create geometry directly in Salomé.

My question is: how can I see where is the overlapping? is it possible to have a list of overlapped faces?
This kind of informations could be very useful to correct the initial step file (because I'm almost sure that the the problem is there :cool:).

Thank you in advance
__________ Piero

franjo_j November 3, 2015 02:36

Hi,

Quote:

Originally Posted by pici (Post 571511)
Hi to everybody,
I'm using a.s.a.p cfMesh (instead of snappyHexMesh), because it is infinitely more friendly then oF.

Thanks, we try to keep it as simple as possible.

Quote:

Originally Posted by pici (Post 571511)
But, when I must import CAD geometry (for complex parts), some time I receive this error message, when I check trisurface .fms mesh, using checkSurfaceMesh utility.

Code:

Found overlapping parts in the surface mesh!!
This causes problems to the automatic refinement procedure. Please avoid using the minCellSize option.

I need to explain my method:
- I import a step file in Salomé (rel 7.6.0)
- I create an opportune set of face groups and, using extractFeatureEdges.py, also the FeatureEdge group
- I create a 2D mesh (only on surfaces) ad I add elements group by geometry
- finally, I export the just created mesh in .fms file, using salomeTriSurf.py utility.
Before to start final meshing process, I check this trimesh using checkSurfaceMesh and very often I receive the message already reported.
It never happens when I create geometry directly in Salomé.

My question is: how can I see where is the overlapping? is it possible to have a list of overlapped faces?
This kind of informations could be very useful to correct the initial step file (because I'm almost sure that the the problem is there :cool:).

Thank you in advance
__________ Piero

checkSurfaceMesh writes the surface mesh together with the subsets of faces failing each check. You can export those subsets into separate files by using: FMSToSurface <input.fms> <output.stl> -exportFeatureEdges -exportSubsets By using -exportSubsets this usitlity writes each subset into a separate vtk file.

Regards,

Franjo

pici November 3, 2015 13:51

Hi Franjo,
thank you very much for your fast reply.
These overlapped faces, are they doubled? is it possible to delete them (e.g. deleting triangles in stl file)?
Thank you in advance. Best regards
__________Piero


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