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problem using polyDualMesh

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Old   July 22, 2012, 20:41
Default problem using polyDualMesh
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Dear all,

Because my tet mesh is too large and runs very slowly in OF, I am trying to use polyDualMesh to convert the tet mesh into a polyhedral mesh.

I am learning this utility by playing with a very simple case, a rectangular flow channel. The tet mesh of the channel fails only one mesh check (small determinant), and works fine giving me results close to the theoretical estimates given by the cubic law. However, after I converted the mesh using 'polyDualMesh 60 -doNotPreserveFaceZone', the mesh failed four tests
high skewness
error in face tets: faces with low quality or negative volume decomposition tets
cells with small determinant found
concave cells found

Then I tried to include the option '-concaveMultiCells'. But the mesh didn't improve at all. I still got all the problems.

I am wondering if there is anything else that I should try when using the polyDualMesh utility to ensure the quality of the mesh generated afterwards.

Truly appreciate any suggestion and comment.

Thank you~

Best,

Hang
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Old   July 25, 2012, 03:08
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Hey there

I am also in the process of trying to use polyhedral meshes.
According to previous posts, the tetra mesh should be produced based on a Delaunay triangulation to produce good results. Does your original mesh satisfy this restriction?
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Old   July 25, 2012, 23:38
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Hi,

Yes, the tet mesh is generated using Delaunay triangulation. And the tet mesh works well in OF. But when I tried to convert it to polyhedral, it fails several mesh tests in 'checkMesh -allGeometry -allTopology'.

Thank you~

Best,

Hang
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Old   August 26, 2012, 07:35
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As future reference, I ended up (partially) answering here: Problem running OF on cluster post #14
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Old   August 26, 2012, 10:11
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Hi Rebecca,

Another thing to keep in mind is that polyDualMesh does not like prism boundary layers much. It has a tendency to mess them up and produce wrong oriented faces.

I believe engrid has included a version of polyDualMesh that works much better with prism layers by not converting them. I think it is only in the development version though.

Philip
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Old   August 6, 2013, 03:42
Default polyDualMesh -- error
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Hello

I am trying to use polyDualMesh for a blower simulation. I am getting an error saying that

--> FOAM FATAL ERROR: Created illegal face 2(4472123 4472125) at position:16171367 when filtering removed points From function polyTopoChange::compact(..) in file polyTopoChange/polyTopoChange/polyTopoChange.C at line 1056. FOAM aborting #0 Foam::error:rintStack(Foam::Ostream&) addr2line failed #1 Foam::error::abort() addr2line failed
then polyDualMesh exits. I am stuck here with this problem. Does any one have an idea why this error happens.. ?

I am using an angle of 40.

Thanks in advance.
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Old   August 17, 2013, 07:47
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Greetings Aditya,

Use the following command to first assess the quality of the mesh:
Code:
checkMesh -allGeometry -allTopology -constant
If it indicates that there are errors in the mesh, then polyDualMesh cannot perform magic...

Best regards,
Bruno
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