CFD Online Discussion Forums

CFD Online Discussion Forums (
-   OpenFOAM Native Meshers: snappyHexMesh and Others (
-   -   Surface Meshes Merged in SnappyHexMesh (Pictures Inlcuded) (

sda December 3, 2012 06:33

Surface Meshes Merged in SnappyHexMesh (Pictures Inlcuded)
4 Attachment(s)
Dear OpeFOAMers,

I am working on a mesh of a generic car body using SnappyHexMesh. There is a region where the surface mesh on two tyres merges witht the wheel wheel of the car body itself.

I am reasonably certain that the .STL file is of good quality so I don't think the geometry is the problem.

I am steadily working my way through the meshing parameters to see which one will effect and improvement but I was hoping to reach that goal sooner with a tip from one of you.

I have included pictures.

Thanks for any suggestions.



sail December 3, 2012 10:08

the problem is that you just have one cell between the tyre and the body and sHM doesn't know how to solve it. increase your mesh resolution in that area to have at least 3 cells between the two surfaces and the issue will disappear. although to have good results you'll probably need more than that---

sda December 3, 2012 10:22


Thanks for your reply. Do I simply increase the refinement on the surfaces or do I increase the values for any of the following parameters below

nCellsBetweenLevels 3;

tolerance 4.0; // under the snapControls



sda December 3, 2012 14:01


Your suggestion was useful but not in the way I expected. I checked the geometry because of your comment and found that a designer had actually moved the wheel. It was touching the wheel arch surface.

After I moved the wheel to the correct position it meshes fine now.

Thanks all the same.



All times are GMT -4. The time now is 06:41.