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Gearb0x April 20, 2010 04:56

Internal Patches : Which boundary conditions?
Dear all,

I have suceeded in incoportaring a fluent mesh with internal patches.

Now I have to choose the boudary conditions I want at this patches but I can't figure out which one to choose.
Zerogradient is not the good solution.

Has anyone ever had such situation and if so what did you do?

Thanks for your help!

Hydro1004 April 20, 2010 20:45


I've just come across this problem also.

If anyone knows of a boundary condition that causes OpenFoam to ignore the boundary (so it has no effect on the fluid flow) it would be great to hear!


herbert April 21, 2010 10:51


what do you mean with "internal patches"? Is it something like a pair "wall" - "wall-shadow"?
If so you can use the stitchMesh utility to make these faces internal.


Gearb0x April 21, 2010 11:33

A very stupid sketch but it explains the situation very cleary :)

herbert April 21, 2010 14:26


I think I understand your problem. The boundary faces should be present twice on two different patches (otherwise they would have owners and neighbours and would therefore be internal). Find the co-located patches (e.g. by checking with paraView) and use
stitchMesh <internalPatch> <colocatedInternalPatch>
for both internal boundaries to make all the faces internal. The entry in the boundary-file should show nFaces=0 after this.

Tell me if it works

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