Hey,

I'm trying to set-up a sliding mesh problem, where I have a large outer region and a inner circular region, which is to be rotated.

When I create the new grid interface, two wall boundaries are automatically created. Strangely, I cannot see these new wall boundaries under display->grid->wall boundaries - the screen stays black...

Anyway, when starting the computation, even without rotating the inner circular zone, the flow seems to be deviated by the circular interface. I suppose it is linked to the automatically generated wall boundaries.

What do I need to do, so that the flow is not influenced by these automatically generated wall boundaries?

Many thanks...

Use gambit to set the boundary as interface, you should have two interfaces at the same location. Or, try to modify the wall conditions as interfaces in Fluent.