CodeSaturne 602 : utiliser un maillage Fluent Meshing comprenant des polyèdres

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fdecrecy
Posts: 5
Joined: Mon Feb 22, 2021 3:22 pm

CodeSaturne 602 : utiliser un maillage Fluent Meshing comprenant des polyèdres

Post by fdecrecy »

Bonjour,

j'ai entendu dire que le solver de Code_Saturne accepte les polyèdres.
Par ailleurs, Fluent Meshing me fait rêver en me montrant qu'on peut faire des superbes maillages avec des polyèdres grâce à leur logiciel.
Seulement je n'arrive pas à lire un maillage généré par Fluent meshing et comprenant des polyèdres avec Code_Saturne, d'où ma grosse déception.

J'ai essayé, en vain, plusieurs choses :
1) utiliser directement le maillage msh.gz généré par fluent meshing (maillage Gmsh) => erreur
2) importer mon maillage msh.gz dans ICEM CFD pour le reexporter en cgns et le lire avec Code_Saturne => ICEM CFD ne lit pas les éléments tétraèdriques
3) Utiliser la fonctionnalité du fluent (le solver, pas fluent meshing) permettant de générer un fichier cgns :
export sans variables
si le maillage ne contient que des tetras, le preprocessing de Code_Saturne 6.0.2 se termine correctement
si le maillage contient des polyèdres, j'ai une erreur de segmentation à la lecture des sommets

Avez-vous déjà utiliser des maillages polyèdriques générés par fluent meshing avec code saturne ?

Je vous remercie d'avance de votre réponse et reste à votre disposition si vous avez besoin de plus d'éléments.
Cordialement,
Florence de Crécy
Yvan Fournier
Posts: 3284
Joined: Mon Feb 20, 2012 3:25 pm

Re: CodeSaturne 602 : utiliser un maillage Fluent Meshing comprenant des polyèdres

Post by Yvan Fournier »

Hello,

Please post in English. There are already a limited number of users who bother to answer others here, and besides me, most are English speakers.

1) Gmsh .msh and FLUENT .msh are not the same format. Gmsh is documented. I never found a freely available documentation for the FLUENT .msh format. So the .msh handled is that from code_saturne, and FLUENT will remain unsupported as long as we have no documentation.

2) I am not familiar enough with ICEM CFD to determine whether this should be expected or not.

3) this is the recommended approach and should work. Though ANSYS sometimes "cheats" on the CGNS version number, making things a mess. Also, the issue may be with the CGNS library version. Which CGNS library version did you try with code_saturne ? The latest is 4.1.2, and seems to work well. Avoid 3.4.0 or 4.0....

I have already tested polyhedral meshes generated by Star-CCM, but probably not from FLUENT meshing.

If you have a small FLUENT-generated CGNS mesh you can post here, I will be happy to check on my side and debug the CGNS import.

Best regards,

Yvan
fdecrecy
Posts: 5
Joined: Mon Feb 22, 2021 3:22 pm

Re: CodeSaturne 602 : utiliser un maillage Fluent Meshing comprenant des polyèdres

Post by fdecrecy »

Hello,

Thank you for your answer. I am sorry for using the French langage.
To explain in english, I can't manage to open a mesh generated with fluent meshing with Code_Saturne, when this mesh has polyedrics elements.

The best way to do it, it to use the fonctionnality of fluent solver to export cgns mesh (with cell centered option and without variables). It works when the mesh only has tetraedres or hexaedres but it doesn't work when the mesh has polyedres.

I use the version 6.0.2 of code_saturne installed on EDF cluster. This version is embarking with salome 2019. And I just see on preprocesseur.log that its use version 3.4.0 of CGNS. So I will try to ask if it is possible to compile code_saturne with version 4.1.2 of CGNS in this cluster.

In the same time, I will try to give you low fluent mesh with polyedres.

Best regards,
Florence
fdecrecy
Posts: 5
Joined: Mon Feb 22, 2021 3:22 pm

Re: CodeSaturne 602 : utiliser un maillage Fluent Meshing comprenant des polyèdres

Post by fdecrecy »

Hello,

you will find attached an archive contained two identical meshes : one which was export with the version 19.2 of Fluent and the other which is exported with the last version of fluent (2020r2). The mesh contains polyedres.

Thank you for your help.

Best regards,
Florence
Attachments
MaillagePolyedresFluent.7z
(1.08 MiB) Downloaded 12 times
Yvan Fournier
Posts: 3284
Joined: Mon Feb 20, 2012 3:25 pm

Re: CodeSaturne 602 : utiliser un maillage Fluent Meshing comprenant des polyèdres

Post by Yvan Fournier »

Hello,

The meshes do not seem to contain volume elements, only polygons.

Are you sure the volume mesh is present, not just the boundaries ?

Best regards,

Yvan
fdecrecy
Posts: 5
Joined: Mon Feb 22, 2021 3:22 pm

Re: CodeSaturne 602 : utiliser un maillage Fluent Meshing comprenant des polyèdres

Post by fdecrecy »

Hello,

thank you for your answer. I do not understand why you couldn't see the polyedric volumes because I correctly see them in my fluent version of the mesh.

Today, the fluent formator gives me a fluent mesh with polyedric elements exported with 3 versions of fluent. All of this mesh work at version 6.0.2 of Code_Saturne (I only tested preprocessing). I do not understand why it works this time and it doesn't work last time !

Thank you for your help.

Best regards,
Florence
Yvan Fournier
Posts: 3284
Joined: Mon Feb 20, 2012 3:25 pm

Re: CodeSaturne 602 : utiliser un maillage Fluent Meshing comprenant des polyèdres

Post by Yvan Fournier »

Hello,

I assume this was due to some incomplete export setting.

If you have a small working example mesh, I can add it to a set of files I keep for testing.

Best regards,

Yvan
fdecrecy
Posts: 5
Joined: Mon Feb 22, 2021 3:22 pm

Re: CodeSaturne 602 : utiliser un maillage Fluent Meshing comprenant des polyèdres

Post by fdecrecy »

Hello,

please find attached an archive with the same fluent mesh containing polyedres export to CGNS by three different versions of fluent : 19.2, 2020r2 and 2021r1. All of these meshes work on Code_Saturne 6.2.0.

Best regards,
Florence
Attachments
MaillageFluentPolyedresFonctionnel.7z
(2.71 MiB) Downloaded 8 times
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