[bongbang]

My model is a sixth of a rotationally symmetric (i.e. periodic) cylinder.

The wall shear stress and its derivative, Oscillatory Shear Index (a measure of how frequently the shear vector changes direction) exhibit a sharp discontinuity in places along the boundary. This doesn't happen consistently. At its worst, it looks distinctly off, while it's barely noticeable at its best. OSI is worse than WSS. The discontinuity exists (albeit in different patterns) whether the "rotational periodic" or "symmetry" condition was applied. A match control has been applied to match the mesh on either side.

This shouldn't happen. Is there a way out of this? Thanks.

OSI



WSS average (very much acceptable, though division still visible)



WSS average, cut moved to a different place.