|December 11, 2009, 04:44||
Join Date: Mar 2009
Posts: 281Rep Power: 11
Dear snappyHexMesh users,
I've been playing with snappy for a few days and I am wondering something. Is it beter to start snappy with a very fine mesh as a base ans only do 1 or 2 level of refinement around my surface, or to start with a coarse mesh and then impose 6or 8 level of refinement in the snappyHexMeshDict?
To give an example, let say we have a mesh at level 1 in blockMesh, the two options are:
- use this mesh and chose a uniform refinement of 4 around the surface in snappy.
- refine blockMesh mesh by 4 in each direction and then use snappy without refinement, or with a refinement level of 1.
Not easy to explain, but i hope you'll understand.
If somebody have an idea, that would be nice.
|December 19, 2009, 15:13||
Join Date: Dec 2009
Location: Hamburg, Germany
Posts: 19Rep Power: 9
the only important thing is the maximum and minimum size of our cells.
When you want to set a refinement with a ratio of 1:8 towards the surface, and the cell size at the surface schould be, lets say 2mm, the initial cell size would be 16mm and the surfaceRefinement-level in sappy would be then 3. (2³=8)
Since very small cells make your solution slower and more unstable, and a too coarse mesh delivers not enough information, this is a important point to think about.
If you are starting with a very coarse mesh from blockMesh, snappy would need perhaps more time for the refinement iterations. But I'm not shure - perhaps you could do some experiments and post the results here.
|Thread||Thread Starter||Forum||Replies||Last Post|
|SnappyHexMesh - How to set-up to avoid skewfaces?||pcaron||OpenFOAM Native Meshers: snappyHexMesh and Others||31||January 15, 2016 06:53|
|SnappyHexMesh with local refinement of ONE STLfile||wolle1982||OpenFOAM Mesh Utilities||16||August 23, 2013 12:12|
|snappyHexMesh "killed"||Bob||OpenFOAM||4||December 1, 2011 17:48|
|SnappyHexMesh hangs during refinement||sjrees||OpenFOAM Native Meshers: snappyHexMesh and Others||4||September 11, 2010 21:59|
|snappyHexMesh - Floating point error||derjames||OpenFOAM Mesh Utilities||4||September 19, 2009 14:14|