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DineshramBalaji June 13, 2013 18:12

Problem in gmsh

I am trying to convert the gmesh file to foam file. But i am getting the following statement.

--> FOAM Warning : Not using gmsh face 4(154822 28524 28525 154823) since zero vertex is not on boundary of polyMesh

Can someone tell, how to correct it?

wyldckat June 15, 2013 11:31

Greetings Dinesh,

According to the warning message, it looks like there is a face on the original mesh that is not on the boundary mesh (i.e. surface mesh). It's possible that you have a zero-thickness cell somewhere in your mesh and OpenFOAM does not like that.

Best regards,

DineshramBalaji June 16, 2013 15:12

Hi bruno,

Thanks for responding. Is there some way to check the zero thickness spot and rectify it?

wyldckat June 16, 2013 15:17

Hi Dinesh,

Doesn't Gmsh have a mesh inspection capability? Try reloading the mesh in Gmsh and search for the point IDs in the list you've gotten:

154822 28524 28525 154823
Best regards,

DineshramBalaji June 16, 2013 15:28

hi bruno,

Thanks again. But there are two problems.

1. this is just a one warning of nearly 115 warnings I got. So instead of locating the cells, is it better to do something before meshing ?

2. should i modify something in the geo file or should I do something else in the gmesh window?

wyldckat June 16, 2013 15:32

Hi Dinesh,

I'm not very familiar with how Gmsh works, but I would suggest that you check the first warning, at least to get an idea of what the problem might be.
Because after that problem is solved, it might solve all of the others or some of them.

Have you checked what Gmsh tells you about the mesh you have? Does it give any warnings on its own?

Best regards,

DineshramBalaji June 16, 2013 15:36

No. The gmesh works perfectly fine. after I converted it to foam file, I checked the mesh and it says mesh ok.

wyldckat June 16, 2013 15:40

What does the full OpenFOAM checkMesh give you?

checkMesh -allTopology -allGeometry -constant
If it doesn't give you any problems, I still suggest that you visually check the first face for the given warning in Gmsh and then check in ParaView the OpenFOAM mesh for the same location.

Because if there is no difference between the two, then I guess the warning can be ignored?!

DineshramBalaji June 16, 2013 15:47


Thanks. Will try that and let u know.

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