[Coris]

I have a problem activating the symmetryPlane BC for one of my boundaries when the mesh is made with cfMesh. This is a known problem, because cfMesh comes with a utility 'improveSymmetryPlanes'. However, this is not enough for the case at hand..

checkMesh before running improveSymmetryPlanes:

--> FOAM FATAL ERROR:
Symmetry plane 'frontSymmetry' is not planar.
At local face at (0.1703081812887766 0.001158095292908665 1.601390638203566e-21) the normal (-1.211793931078213e-17 -4.239402769195217e-18 -1) differs from the average normal (3.522462206000439e-06 1.550530335361962e-07 -0.9999999996709624) by 1.243178154426267e-11
Either split the patch into planar parts or use the symmetry patch type

From function void Foam::symmetryPlanePolyPatch::calcGeometry(Foam::P streamBuffers &)
in file meshes/polyMesh/polyPatches/constraint/symmetryPlane/symmetryPlanePolyPatch.C at line 64.

and after:

--> FOAM FATAL ERROR:
Symmetry plane 'frontSymmetry' is not planar.
At local face at (0.1703081812888498 0.001158095292911979 -6.686652924327499e-08) the normal (1.094760291316228e-06 4.90293024478426e-08 -0.9999999999993996) differs from the average normal (6.28184762184831e-07 4.89799734796166e-08 -0.9999999999492696) by 2.176927293306086e-13
Either split the patch into planar parts or use the symmetry patch type

From function void Foam::symmetryPlanePolyPatch::calcGeometry(Foam::P streamBuffers &)
in file meshes/polyMesh/polyPatches/constraint/symmetryPlane/symmetryPlanePolyPatch.C at line 64.

FOAM exiting

so definitely, there is an improvement, but not enough.

I have tried some stuff, ie:
- flattenMesh utility, by temporarily changing the symmetryPlane to empty --> messes up the mesh (edit: this is normal, because flattenMesh supposes a 2D geometry and acts on all nodes/points)
- changing the meshing in the neighbourhoud of the problem area --> no effect
- controlDict: increasing writePrecision --> no effect
- controlDict: binary instead of ascii --> improveSymmetryPlanes doesn't work

I would rather not change to symmetry bc instead of symmetryPlane, because I strongly suspect this is the cause for not being able to converge the simulation I am running with the mesh.

Any other ideas?
Unfortunately, I cannot upload my current model and the minimal working example I have, doesn't display this behaviour.