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-   -   mismatch between faces of periodic domains (https://www.cfd-online.com/Forums/pointwise/133550-mismatch-between-faces-periodic-domains.html)

zhengzh5 April 16, 2014 13:31

mismatch between faces of periodic domains
 
Hi,

I created a structured domain, and used it to create a periodic domain with a rotation of 40 degrees in my mesh. It all seems to be going well until I exported the mesh to OpenFOAM and performed a checkMesh. It essentially complains about the faces not matching each other. I did a quick visualization in paraview using the labelID specified by the checkMesh error and found that the 2 faces that are supposed to be matched in the cyclic BC are completely off. They are located on the opposite end of the periodic domain....

Does anyone know what's going on there?

Thanks,

Jason

pdp.aero April 16, 2014 16:59

Quote:

Originally Posted by zhengzh5 (Post 486553)
Hi,

I created a structured domain, and used it to create a periodic domain with a rotation of 40 degrees in my mesh. It all seems to be going well until I exported the mesh to OpenFOAM and performed a checkMesh. It essentially complains about the faces not matching each other. I did a quick visualization in paraview using the labelID specified by the checkMesh error and found that the 2 faces that are supposed to be matched in the cyclic BC are completely off. They are located on the opposite end of the periodic domain....

Does anyone know what's going on there?

Thanks,

Jason

Hi Jason,

Can you please attach your grid's picture? your axis along with your periodic domains.
My first suggestion is make sure that your axis is perfectly straight and horizontal (depends on your axis direction though.)

dgarlisch April 17, 2014 10:56

This is a known limitation (bug) in the Pointwise OpenFOAM (OF) exporter.

The faces on matched periodic/cyclic boundaries are not numbered in the correct order.

The only workaround is to adjust the exported grid with OF tools. Someone else with OF skills will need to give you details on how to run these tools.

Please submit a bug report to Pointwise support.

cnsidero April 17, 2014 15:32

Quote:

Originally Posted by zhengzh5 (Post 486553)
Hi,

I created a structured domain, and used it to create a periodic domain with a rotation of 40 degrees in my mesh. It all seems to be going well until I exported the mesh to OpenFOAM and performed a checkMesh. It essentially complains about the faces not matching each other. I did a quick visualization in paraview using the labelID specified by the checkMesh error and found that the 2 faces that are supposed to be matched in the cyclic BC are completely off. They are located on the opposite end of the periodic domain....

Does anyone know what's going on there?

Thanks,

Jason

The matching of periodic domains created in Pointwise is lost when exported to OpenFOAM. Geometrically the points and faces are periodic but the face ordering - as you've found out - is not guaranteed.

You can however recreate the periodic coupling, called cyclic in OpenFOAM-speak, using the createPatch utility. Refer to the location of the createPatch utility

Code:

$FOAM_UTILITIES/mesh/manipulation/createPatch/
for an example createPatchDict that is set up to recreate cyclic coupling between patches.

-Chris


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