Polyhedral mesh has many more celle than standard mesh

klausb · March 14, 2015, 14:42

Hello,

I did the throttle tutorial using engrid 1.4. In addition to the mesh described in the tutorial, I divided the boundary layer into 10 layers.

After completing the mesh, I exported it for OpenFoam as the standard tetrahedral mesh and after that as polyhedral mesh.

I was surprised, that the polyhedral mesh had about three times the number of cells (according to paraFoam) and file size. I expected, that the number of cells would decrease while the file size might slightly increase as more information needs to be stored per polyhedral mesh cell.

What's causing this strange behavior?

Klaus

dybuk · March 16, 2015, 02:43

Check your mesh witch checkMesh application. By default paraView decompose polyhedra into tets and prisms for visualization.

klausb · March 16, 2015, 08:01

Hello,

thank you for the hint!

According to checkMesh, the number of cells went down from about 116.000 to about 92.000 cells.

The mesh size went up from 12.7MB to 16.4MB.

Both results are in line with expectations.

Klaus

March 16, 2015, 08:01	ok, checkMesh results are in line with expectations	#3
klausb Senior Member Klaus Join Date: Mar 2009 Posts: 250 Rep Power: 22	Hello, thank you for the hint! According to checkMesh, the number of cells went down from about 116.000 to about 92.000 cells. The mesh size went up from 12.7MB to 16.4MB. Both results are in line with expectations. Klaus

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March 16, 2015, 02:43		#2
dybuk Member W.T Join Date: Oct 2012 Posts: 35 Rep Power: 13	Check your mesh witch checkMesh application. By default paraView decompose polyhedra into tets and prisms for visualization.