CFD Online Discussion Forums

CFD Online Discussion Forums (http://www.cfd-online.com/Forums/)
-   ANSYS Meshing & Geometry (http://www.cfd-online.com/Forums/ansys-meshing/)
-   -   [Gambit] inverted elements / negative volume (http://www.cfd-online.com/Forums/ansys-meshing/72883-gambit-inverted-elements-negative-volume.html)

jack1980 February 20, 2010 12:54

[Gambit] inverted elements / negative volume
 
Hi,

In Gambit I ran into a strange problem. When I mesh a certain face, the grid is out of the plane of the face. I get the following message:

"ERROR: ACIS error 43001 : coincident face_face_ints with different body vertices"

The strange thing is that I had no difficulties at all with coarser meshes for the exact same geometry.

However, I can still mesh the associated volume (with some highly skewed elements) and write a .msh file. I can read it in Fluent, but the grid check fails: the problem appears to be that I have 6171095 right-handed and 26 left-handed faces. Still, in Fluent the grid contains the correct number of elements. I can initialize, but when I try to iterate Fluent returns:

"Error: divergence detected in AMG solver: pressure correction"

So, I'm pretty sure something is wrong with this face. It appears to cause some troubles, such that I can't iterate in Fluent.

Furthermore, if I decrease the element size at the (distorted grid) face edge, Gambit will mesh the face but won't mesh the associated volume anymore:

"inverted elements (negative VOLUME)"

I really hope somebody can help me out here. Especially since the results on the coarser grids looked so promising.

Thanks!

Update:
I tried TUI: /grid/modify-zones/repair-face-handednes
This returned: "Left-handed faces can't be converted to right-handed faces. All face nodes have the right order, but the mesh probably contains non-convex cells."

-mAx- February 22, 2010 02:50

I would try to split your face which gives you trouble.
Enforcing the presence of edge(s) on the surface may help and solve your problem.
Already experienced this case


All times are GMT -4. The time now is 22:54.