[6863523]

Dear,
I am trying to mesh a complex geometry in Salome 7.8.0.
But I have always met a problem

 unexpected geometry : topology of source and target faces seems different

with the projection algorithm.
The python script for generating the mesh has been attached.
Any suggestions would be appreciated.
Thank you in advance.
Best Regards,
Bill

[6863523]

Thank you for your attentions.
Problem has been solved.
The link below may help the new learners of Salome.
http://docs.salome-platform.org/late...algo_page.html

[6863523]

Dear,

The mesh is OK.
However, when I tried to use the createPatch function, there is always an error like this:

--> FOAM FATAL ERROR:
 For patch left there are 720 face centres, for the neighbour patch right there are 864
  
     From function void Foam::cyclicPolyPatch::calcTransforms(const  primitivePatch&, const pointField&, const vectorField&,  const pointField&, const vectorField&
     in file meshes/polyMesh/polyPatches/constraint/cyclic/cyclicPolyPatch.C at line 156.
  
 FOAM exiting

I want to use the cyclic boundary conditions, it seems that I need to use the projection algorithm to create cyclic boundaries, according to the thread here http://www.salome-platform.org/forum/forum_10/272693881
Any suggestions would be appreciated.
Thank you in advance.
Best Regards,
Bill

[6863523]

Dear,
I have checked again.
The error actually occurs when I tried to transfer the mesh into OpenFOAM, using the ideasUnvToFoam function.

Sorting boundary faces according to group (patch)
0: LEFT is patch
1: RIGHT is patch
2: BOTTOM is patch
3: TOP is patch
4: FRONTANDBACK is patch
5: SOLID is patch

Constructing mesh with non-default patches of size:
    LEFT	720
    RIGHT	864
    BOTTOM	729
    TOP	728
    FRONTANDBACK	2988514
    SOLID	55600

End

When I use the createPatch function, another error shows up

--> FOAM FATAL ERROR: 
For patch left there are 720 face centres, for the neighbour patch right there are 864

    From function cyclicPolyPatch::calcTransforms()
    in file meshes/polyMesh/polyPatches/constraint/cyclic/cyclicPolyPatch.C at line 161.

FOAM exiting

The mesh was created without projection algorithm in Salome.
Obviously, the error was caused by the unequal number of faces on the opposite boundaries (front and back, left and right, bottom and top), which should be of the same number.
However, when I tried to use the projection algorithm to generate mesh, there is always an error as in #1.
Any suggestions would be appreciated.
Thank you in advance.
Best Regards,
Bill

[ykanani]

Originally Posted by 6863523

Dear,
I have checked again.
The error actually occurs when I tried to transfer the mesh into OpenFOAM, using the ideasUnvToFoam function.

Sorting boundary faces according to group (patch)
0: LEFT is patch
1: RIGHT is patch
2: BOTTOM is patch
3: TOP is patch
4: FRONTANDBACK is patch
5: SOLID is patch

Constructing mesh with non-default patches of size:
    LEFT	720
    RIGHT	864
    BOTTOM	729
    TOP	728
    FRONTANDBACK	2988514
    SOLID	55600

End

When I use the createPatch function, another error shows up

--> FOAM FATAL ERROR: 
For patch left there are 720 face centres, for the neighbour patch right there are 864

    From function cyclicPolyPatch::calcTransforms()
    in file meshes/polyMesh/polyPatches/constraint/cyclic/cyclicPolyPatch.C at line 161.

FOAM exiting

The mesh was created without projection algorithm in Salome.
Obviously, the error was caused by the unequal number of faces on the opposite boundaries (front and back, left and right, bottom and top), which should be of the same number.
However, when I tried to use the projection algorithm to generate mesh, there is always an error as in #1.
Any suggestions would be appreciated.
Thank you in advance.
Best Regards,
Bill

Hello Bill,
Thanks for reaching out to me. Unfortunately I am not familiar with Salome grid generation. However, here is what I think about your problem:

1- If you are sure that you have identical patches in your grid, then there is something wrong in exporting the grid and converting it to the opemfoam

2 - You always can use CyclicAMI for non-identical patches (but in case that you cannot make patches identical)

As I said, I don't have any experience with this grid generation but it is less probable that openfoam conversion is causing the problem. So I think it is better to double check you grid in Salome and make sure that those patches are identical.

Regards,
Yousef

[6863523]

Originally Posted by ykanani

Hello Bill,
Thanks for reaching out to me. Unfortunately I am not familiar with Salome grid generation. However, here is what I think about your problem:

1- If you are sure that you have identical patches in your grid, then there is something wrong in exporting the grid and converting it to the opemfoam

2 - You always can use CyclicAMI for non-identical patches (but in case that you cannot make patches identical)

As I said, I don't have any experience with this grid generation but it is less probable that openfoam conversion is causing the problem. So I think it is better to double check you grid in Salome and make sure that those patches are identical.

Regards,
Yousef

Dear Yousef,
Thank you very much for your reply.
Actually,I agree with you, I believe there is something wrong with the generation of mesh in Salome, as I have succeeded in one structure, however, when I changed the structure, there is this problem.
Any way, thanks for your attention.
Best Regards,
Bill

[Linse]

Dear Bill,

I suggest retrying the mesh conversion using the - in my opinion much better - python script written directly for that purpose. You will find it by looking for salomeToOpenFOAM.py quite easily, I think...

[6863523]

Originally Posted by Linse

Dear Bill,

I suggest retrying the mesh conversion using the - in my opinion much better - python script written directly for that purpose. You will find it by looking for salomeToOpenFOAM.py quite easily, I think...

Dear Linse,
I have tried the script before.
I believe it is caused by the mesh, if the mesh can be generated properly, there will not be such problem.
Thank you in advance.
Best Regards,
Bill

[6863523]

Dear,
I rechecked the geometry and made some modifications to ensure that the opposite boudaries are exactly the same, and there is no such error.
The mesh generation seems good. The number of faces on the opposite boundaries is the same.
However, when I check mesh in OpenFOAM, it tells me there are "severely non-orthogonal faces and skewed faces" and mesh check failed.
However, when I check the skewed faces in Salome, the element seems normal, as in the attachment.

I wonder if any one knows how to avoid such severely non-orthogonal faces in salome.
Thank you in advance.
Best Regards,
Bill