I am solving a natural convection problem in a room using fluent. The hexahedral grid for the room was developed in gambit. When I import the *.msh file in fluent 3d, and view the grid in any cut section, I observe a random curve in any cut section. All along the curve cells have random lines cutting across them. Some times these lines form diagonal and sometimes not. Some of these cells even have more than one line cutting across the cell. This odd behaviour is seen only in cells along a curve. Infact this curve I see is imaginary and appears due to these irregular cells only which are showing extra line through them. All other cells look perfect squares.

This problem is not removed by smoothing the grid. More over such irregular cells are not visible in gambit. Gambit view is as per expectation.

Can Any body give the clue to this behaviour of fluent.

My other colleagues have also reported this feature.

Thanks in advance.

nirupam

do u use 2 ore more licences? If so, Fluent divides the geometry in 2 or more parts, and what u see might be the plane, where the parts are attached.

I have esperienced the same. Quite annoying if you have several slave machines. Any chance of removing the odd line?

You stated the reason yourself... "This odd behaviour is seen only in cells along a curve"

What's happening is that your cut isn't perfectly aligned with the cells. When you create a surface, wherever that surface intersects an edge, you will get a vertex, whenever it intersects a face you will get an edge, and whenever it intersects a volume, you will get a face. If the face is perfectly aligned with the surface, then you will see perfect faces on your surface, but otherwise you will see what looks like a mess of lines.

Once your mesh is built, there's really nothing you can do about this. If you know you want these cuts in advance, then you can build them into your Gambit model before meshing. If you're just trying to create images of the mesh, I recommend doing it in Gambit using the Examine mesh feature (icon on the bottom right of the toolbar... looks like a yellow grid with a magnifying glass over it).

Hope this helps, and good luck, Jason

Dear Ralf,

No I am using only one license. This problem is seen in all the cut-planes, at any level and in any direction.

There is somthing else to it.

thanks

nirupam