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-   -   Periodics using ICEM and OpenFOAM (http://www.cfd-online.com/Forums/openfoam-meshing-other/123003-periodics-using-icem-openfoam.html)

agval79 September 2, 2013 12:27

Periodics using ICEM and OpenFOAM
 
Dear all,
I have been meshing a simple geometry with ICEM and GAMBIT in order to run some incompressible problems (image attached). I have 2 periodic surfaces. However, dealing with these surfaces has been a nightmare. I have used both programs with different mesh sizes and Boundary conditions with no luck. The closest that I have been is at 8% of difference between surfaces.

https://cardiffmail01.cf.ac.uk/mail1...ElemFormat=gif

Also, I have
* increased the matchTolerance
* increased the writePrecision to 12
* used the command of "Set up Periodicity" in ICEM

But nothing!. Does anyone have any suggestion on how to deal with this issue? I think the converted is not recognising the relation between surfaces, but how can I change that?

Thanks.

markusrehm September 4, 2013 06:11

Hi Agustin,

I had a similar problem. In my case it was because of the block vertices which were not exactly at the position of the geometry points.

In my case it was a 60 axi symmetric case. I had to put points at the corners of the first cyclic patch and rotate them. Then I forced (snapped) the vertices of the blocks to these rotated points.

The ICEM mesh I exported worked well that way. But I think in terms of tolerance it was also around 0.05.

Which cyclic boundary condition are you using?

Markus

agval79 September 4, 2013 13:00

Thanks!.
 
Hi Markus,

Thanks for the advice. I changed the periodic vertices in order to make them easier to spot by the program. Also, remade the geometry to have a coherent periodicity of 40 degrees. Finally, increased the matchTolerance to 0.05, and it's working now!.

Thanks a lot. :)


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