Null determinant cells in Netgen
Meshing a simple geometry using Netgen I obtained some null-determinant cells that crash a solver (see http://www.cfd-online.com/Forums/ope...tml#post402809)
Enclosed you can find pictures of the mesh and the file of the .brep geometry.
The white coloured cells are the null-determinant ones.
Is there anyone able to solve this problem ? Is there any guideline to follow to avoid this cells ?
More: Why did they come in such a simple case ?
Success in SALOME
I generated both meshes in SALOME without any problem.
1. Simple mesh NETGEN 1D-2D-3D with very fine settings.
2. Mesh with refinement on edges.
I did not mesh conversion due to i have not OF on my working computer, but SALOME didn't detect zero volumes so i think there is no elements with negative determinant.
P.S. I use SALOME on Win7
Thanks for your time. Have you tried to check your mesh with:
checkMesh -allGeometry -allTopology
and see how many (and if...) undeterminet cells it has ?
BTW: I use Salome but just to preprocess existing STEP geometry. Then usually I use SHM. I tried several times meshing with it but I found it quite instable (i.e. lots of crash), above all making submesh.
Which version are you using ? Do you download it from the official site ?
Here my checkMesh output:
I use version 6.4 32-bit from official website.
Can you please execute checkMesh with -allGeometry -allTopology options ?
PS. I really hope you had find a good way to avoid these cells...
I executed it with options -allGeometry -allTopology and got an undetermined cells as you describe.
It was pretty strange so i did checkMesh with the same options but on my nozzle head case. The mesh was also generated using SALOME.
So i got same cells in the similar positions as in your case.
So i think you need keep it simple) it's not your fault
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