[cfMesh] Refinement diffusion or in snappy-variables: nCellsBetweenLevels

schiffbauer · April 12, 2019, 04:40

Dear Foamers,

cfMesh has a lot advantages over snappy, but one point seems to be a problem:

How can I increase the number of cells between levels? In snappy, the variable is: nCellsBetweenLevels.

Usually cfMesh puts only one or two cells between different refinement levels which leads to a bad mesh quality and to solver issues i.e. with DES-approaches.

Swift · April 15, 2019, 05:41

Hi Gerd,

I couldn't find an obvious solution like snappyHexMesh would use.

Could you play with the other refinement options, such as refinementThickness and cellSize options to get the mesh size distribution that you want?

For example if you have two mesh areas with two mesh sizes, could you create a refinement area between those zones and specify an intermediate cell size. This should help get a better cell size distribution which may resolve the quality issues.

Its a bit of a workaround, but may help.

Regards,
Thomas

bennn · February 16, 2020, 17:37

Hi all,

I also think that is a neat feature of Snappy, and a good way to get quality meshes. I think it would be a great addition to cfmesh !

April 12, 2019, 04:40	Refinement diffusion or in snappy-variables: nCellsBetweenLevels	#1
schiffbauer New Member Gerd Fade Join Date: Jul 2015 Posts: 7 Rep Power: 10	Dear Foamers, cfMesh has a lot advantages over snappy, but one point seems to be a problem: How can I increase the number of cells between levels? In snappy, the variable is: nCellsBetweenLevels. Usually cfMesh puts only one or two cells between different refinement levels which leads to a bad mesh quality and to solver issues i.e. with DES-approaches.

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April 15, 2019, 05:41		#2
Swift Member Thomas Sprich Join Date: Mar 2015 Posts: 76 Rep Power: 11	Hi Gerd, I couldn't find an obvious solution like snappyHexMesh would use. Could you play with the other refinement options, such as refinementThickness and cellSize options to get the mesh size distribution that you want? For example if you have two mesh areas with two mesh sizes, could you create a refinement area between those zones and specify an intermediate cell size. This should help get a better cell size distribution which may resolve the quality issues. Its a bit of a workaround, but may help. Regards, Thomas

February 16, 2020, 17:37		#3
bennn Member benoit paillard Join Date: Mar 2010 Posts: 96 Rep Power: 16	Hi all, I also think that is a neat feature of Snappy, and a good way to get quality meshes. I think it would be a great addition to cfmesh !