[caduqued]

Hi there Foamers,

I am facing a quite curious situation. I am meshing a simple geometry (just a parallelepiped), but with four cyclic boundaries (2 sets of 2 faces each). After running blockMesh I check the mesh with checkMesh and I am getting non-orthogonality errors.

I decided to check one of the tutorials, just to be sure I had done nothing dumb within the blockMeshDict, just to be safe. I took the channel395 tutorial, and after creating the mesh, again checked the mesh with checkMesh. The summary of checkMesh for this geometry is the following:

Checking geometry...
Overall domain bounding box (0 0 0) (4 2 2)
Mesh (non-empty, non-wedge) directions (1 1 1)
Mesh (non-empty) directions (1 1 1)
Boundary openness (-2.20985e-16 -3.05745e-18 3.30302e-17) OK.
Max cell openness = 1.5351e-16 OK.
Max aspect ratio = 10.4192 OK.
Minimum face area = 0.000639842. Maximum face area = 0.0102758. Face area magnitudes OK.
Min volume = 6.39842e-05. Max volume = 0.000685055. Total volume = 16. Cell volumes OK.
Mesh non-orthogonality Max: 180 average: 16.0853
***Number of non-orthogonality errors: 7000.
<<Writing 7000 non-orthogonal faces to set nonOrthoFaces
Face pyramids OK.
Max skewness = 3.9073e-11 OK.
Coupled point location match (average 3.39872e-19) OK.

Failed 1 mesh checks.


My question is:

Is OK to ignore this message for those cases with periodic (cyclic) boundaries?

It is a bit concerning that checkMesh seems to ignore that is dealing with a geometry with cyclic boundaries, and then includes such features as fault or mesh errors. Then, it is very difficult to distinguish from real problems, for instance, in more complex geometries.

Any feedback is really appreciated.

Carlos

[wyldckat]

Greetings Carlos,

At first I was going to say this is normal and suggest that your report this as a bug... but then I tested the tutorial "DNS/dnsFoam/boxTurb16" with both OpenFOAM 2.2.0 and 2.2.x:

• On 2.2.0, I got the same message from checkMesh as you did.
• On 2.2.x, it no longer gives this message. This means that it has been fixed some time ago...

For more information on how to install OpenFOAM 2.2.x: http://www.openfoam.org/git.php

At least in theory, I think you can safely disregard the message you're seeing, if you don't want to install 2.2.x.

Best regards,
Bruno

[caduqued]

Originally Posted by wyldckat

Greetings Carlos,

At first I was going to say this is normal and suggest that your report this as a bug... but then I tested the tutorial "DNS/dnsFoam/boxTurb16" with both OpenFOAM 2.2.0 and 2.2.x:

• On 2.2.0, I got the same message from checkMesh as you did.
• On 2.2.x, it no longer gives this message. This means that it has been fixed some time ago...

For more information on how to install OpenFOAM 2.2.x: http://www.openfoam.org/git.php

At least in theory, I think you can safely disregard the message you're seeing, if you don't want to install 2.2.x.

Best regards,
Bruno

Hi Bruno,

Thanks for the info. Yes, I had been using current versions up to 2.1.x, but then I moved to 2.2.0 and got stuck there. Anyway, it is good to know that it has been fixed. Thanks again.

Carlos