CFD Online Discussion Forums - Gambit map meshing scheme

Gambit goes through and makes some assumption of how the mesh should look at corners based on the angle of the edges as they intersect and will define a vertex type label (look in the Gambit manual, specifically the section on Vertex Types for more detailed info). For a mapped mesh, there must be 4 "end" vertices, and all the rest have to be "side"... for submapped mesh you will have extra "end" vertices and "corner" vertices, but there has to be 4 more "end" vertices than "corner" vertices. For either case, there can be as many "side" vertices as you want.

Quick descriptions... an "end" vertex is an inside corner (if you have a square and you are meshing the inside of the square, then the 4 corners are "end" vertices... there is only 1 element touching this vertex)... a "corner" vertex is an outside corner (if you are trying to mesh an L shaped face, then the vertex at the bend of the L is a "corner" vertex and there are 3 elements touching this vertex). A "side" vertex can be any vertex on the side of the square and will have 2 elements touching it.

Those are the only vertex types allowed when using the mapped or submap scheme. Sometimes you can force the mapped scheme, and Gambit will recognize what you're trying to do no matter what the vertex types are and will adjust the vertex types to get you what you want. Other times you have to manually go in and modify the vertex types. You can find this command in the face mesh tools.

The vertex type label is only common to that vertex on that face... if the vertex is shared by multiple faces, it will have a different vertex label associated with each face that shares it (in one face it could be an "end" vertex, while in another it could be a "corner" vertex).

There's much better descriptions of all of the vertex types in the Gambit manual.

Hope this helps, and good luck, Jason