[FluidCFD]

Hi,

I tried to mesh the geometry (see Geometry.png) as a structured grid with hexas. The problematic area is marked with a red frame. When importing the mesh in CFX and try to run it, a message pops up saying that there are some negative elements (see Primitive2D.png). The blocks in the problematic region can be seen in Blocks.png. I tried to get rid of those elements by refining the mesh or changing the blocks slightly, but nothing helped. There is a rather small gap between the pipe and the lid. Somehow the mesher can't cope with the region lying behind this geometry. Anyone an idea?

Best regards.
G.

[Ludvik]

In Blocking use "Block Check" (red tag button) and select "Fix Inverted Blocks". In Edit Mesh try "Check Mesh" and "Volume Orientation".

[FluidCFD]

Hi,

that was a nice hint as ICEM detects the problematic area but did not really solve the problem. I said "Fix" when error messages occured in the "Check Mesh" process. But the "Negative element volume" error still persists in CFX.

Any other idea?

Best regards.
J.

[FluidCFD]

Hi,

I finally solved the problem. "Edit Mesh" -> "Check Mesh" could not fix all the problematic elements and stated "that the elements were too bad to be fixed." So sometimes, the fixing process fails. I changed the blocks I used by making them slightly larger at some edges and suddenly it worked. So it was just "try and error" strategy and a little bit of luck.

Best regards.
G.