Hi, this is a bit long but interesting problem...

I an trying to implement ghost cells in case of unstructured grids, which may have poly hedra cells.

Usually we take reflection of boundary cell across the face on bdry to get the ghost cell. But in case of unstructured grids, the boundary face may not be a planar structure. Which means i dont have a unique plane accross which i can reflect the cell !

If anyone has any suggestion on how to create ghost cell in such case or info on paper abt this, please do let me know...

thnx in advance, sunny

Hi,

I assume you're using the FVM. In that case, you are specifying only one value for the face (no matter how warped) and it is specified in the face centroid using the face normal. Those two pieces of data specify a plane around which you will do the mirroring; the rest is straightforward.

Incodentally, if you're doing a symmetry plane (or similar) boundary condition, your face should by definition be flat, so if it isn't you've already screwed up in mesh generation.

Hrv