[heling]

Dear cfd-users,

I'm trying to create a mesh inside a 3d-channel with a hill on the bottom. All channel walls in except of the lower wall I created with BlockMesh. The bottom geometry including the bump I put in the constant/triSurface directory as a .stl file.

Although it seems to be a relatively simple geometry I get some considerable issues during the layers adding. The boundary layers on the bump (but solely on the bump, see attached pict.) are highly warped, at many places overgrown itself or even don't exist. In all probability the problem is causes by inadequately quality of the bump surface.

First I thought I should in the snappyHexMeshDict file just increase the level of surface refinement and the number of smoothing iterations before finding a correspondence to the surface. In except of computation time nothing changes xD

My 2nd presumption was that the bad surface quality is caused by incorrect facet normals orientation. I checked the normals in the .stl file with a self-made matlab code and yes, a lot of normals wasn't vertical on the triangular faces, as should be. Then I wrote a code to reorient the normals but the issue still occur... Below I attached a few pictures showing my problem, an the complete foam run directory with all dictionaries.

I will be very grateful for some helpful advices.


Attachment description:

pict0: whole channel geometry created with blockMesh and sHM, without edges

cut1: x normal, cut in the middle of the bump: as You can recognize in the middle of the hill the surface is relatively smooth, then on the sides strongly warped...

cut2: z normal

cut3: z normal & x normal: as You can easily recognize on the ragged sides of the bump no layers have been added...

Download link for run directory:
https://docs.google.com/file/d/0B-av...it?usp=sharing