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-   -   [ICEM] Volumetric Mesh (http://www.cfd-online.com/Forums/ansys-meshing/69236-volumetric-mesh.html)

apantune October 16, 2009 08:17

Volumetric Mesh
 
2 Attachment(s)
Hi,
I am wondering why Icem produces such a warp tetra, like those shown on the attached figure. The tetra elements around the prism cap are relatively homogeneous but suddenly you see this discrepant tetra!
The figures are correspondent to a plane cut over the 3D mesh (50 millions).

Regards,
Alex.

PSYMN October 18, 2009 00:46

Tetra Tumors.
 
Arg! We call those "tetra Tumors", they are a glitch in the Delaunay code that sometimes pops up :(. A developer once explained it to me in technical terms, it has something to do with... never mind.

You could repair them by deleting just those elements and running Delaunay again with the "fill holes" option.

This problem was fixed in 12.0 if you use the Beta option for Delaunay called "TGLib". You could also use the Advancing front option to avoid this.

At 12.1, this TGlib option is no longer Beta, plus there is a control to turn on/off the AFT (Advancing Front) option.

PSYMN October 18, 2009 00:47

Better transition may help...
 
You may also want to create a Density box around your airfoil to prevent the mesh from changing size so suddenly... You can also adjust the expansion rate...

Either of these changes may be enough to prevent the tetra tumors even with 11.0 delaunay.:)


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