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-   -   [GAMBIT] tangent edges and high skewness (http://www.cfd-online.com/Forums/ansys-meshing/101437-tangent-edges-high-skewness.html)

CaroVandame May 3, 2012 22:21

tangent edges and high skewness
 
Hello everyone

I'm trying to mesh a bagless filter which looks like the one on the picture with hexahedral cells only.
At first my inlet was one volume and my "center piece" was another one. However, it creates a very small sliver at the connection, and meshing it leads to high skewness cells.

Here are my questions:
-is there an easy way to select a particular cell and refine it in one direction in Gambit?
-is this one case where using virtual geometries could help? I could create virtual faces that include both my sliver face and my central face, and mesh it easily, however, at the connections planes, how do I match the meshes?

Any idea/tip/... will be greatly appreciated, I'm quite new to Gambit!

Thanks
Caroline

http://www.czba.com/images/CycloJet_100_CFD.jpg

CaroVandame May 3, 2012 22:25

Or third question: can Fluent directly adapt cells under a certain quality threshold? And can you adapt only in one direction?

Far May 4, 2012 00:34

Similar, but done in ICEM
 
http://www.youtube.com/watch?v=KabKFrJK3fM

http://www.youtube.com/watch?v=hkHoXMCpfMk

-mAx- May 4, 2012 01:28

can you post a picture with a zoom at your skewed cells

CaroVandame May 4, 2012 09:41

Very interesting video, thanks, but like mAx, I wonder what your skewness is at the tangent point?

It is easy to create the same kind of mesh in Gambit, but the cells at the tangent junction are highly skewed...

CaroVandame May 4, 2012 15:45

What about tmerge?
The good point is I can define the cylinder slice at the level of the inlet and the inlet as one volume, and I can mesh it easily (the sliver disappears inside the bottom face). However, part of this "merged" bottom face needs to be defined as interior and the other one as wall. I don't know how to do that. Creating virtual faces doesn't help since they don't get exported.
Any input?

CaroVandame May 4, 2012 19:37

UPDATE: it seems that tmerge is the way to go (or use Fluent's ability to open multiple meshes at once).
Now I have problems with Fluent to create the grid interfaces, so I'll open a new thread in the right forum!

Thanks everyone

Far May 7, 2012 02:11

For grid interfaces (in gambit), you should search the older posts by -mAx-, where he has explained very nicely that how to decouple two volumes and create the interfaces.

AND/OR

If you can send geometry privately or attach on forum, then I can make the mesh for your in ICEM CFD.

CaroVandame May 7, 2012 09:39

Thanks Far, but I think I figured it out!
Like you said, mAx posts were quite useful.

Here is the new thread if someone is interested.
http://www.cfd-online.com/Forums/flu...tml#post359498


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