[Other] Mesh size functions

Bdew8556 · March 11, 2019, 19:28

Hey all,

I'm new to OpenFOAM and just making my way through the literature, tutorials etc....

Does anyone have any comment as to how to incorporate inflation, proximity and curvature size functions into openfoam?

Much appreciated.

Brett

simrego · March 14, 2019, 04:31

Hi!

In SHm you can use feature angle as a curvature related refinement.
For the proximity I think there is no option but you can use gap detection so you can automatically detect small gaps. If you have a really high angle between 2 surfaces, for example you mesh a wing(not the fluid but the wing itself) at the trailing edge you have 2 surfaces with a high angle. SHm will detect it as a "gap" so automatic refinement will be also done in these cases.
If you are on the other side of the domain (fluid), then then you have to use the feature refinement.

Bdew8556 · March 14, 2019, 04:40

Thanks simrego!

I've been having some troubles with sHM.

At the moment I'm trying to mesh an airfoil within a 3D domain where the foil edges dont touch the sides of the domain.

Do you know of any example sHMDict files that could be a good template?

simrego · March 14, 2019, 04:48

In the tutorials there is a mesh folder and a SHM folder in it where you can find examples, or check the motorBike tutorial.

Depending on the version you are using some explanation can be found here:
OFv6 (FOUNDATION version):
https://cfd.direct/openfoam/user-gui...snappyhexmesh/
or v1812 (esi group version):
https://openfoam.com/documentation/g...pyhexmesh.html

What works in OF 6 it is usually also working in the esi version, but not vice-versa.
And the esi version has more functionality (I think gap detection is not implemented in OF6 but I'm not 100% sure, also different mesh smoothing for layer insertion, etc.).

March 11, 2019, 19:28	Mesh size functions	#1
Bdew8556 Senior Member Brett Join Date: May 2013 Posts: 212 Rep Power: 13	Hey all, I'm new to OpenFOAM and just making my way through the literature, tutorials etc.... Does anyone have any comment as to how to incorporate inflation, proximity and curvature size functions into openfoam? Much appreciated. Brett

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March 14, 2019, 04:31		#2
simrego Senior Member anonymous Join Date: Jan 2016 Posts: 416 Rep Power: 14	Hi! In SHm you can use feature angle as a curvature related refinement. For the proximity I think there is no option but you can use gap detection so you can automatically detect small gaps. If you have a really high angle between 2 surfaces, for example you mesh a wing(not the fluid but the wing itself) at the trailing edge you have 2 surfaces with a high angle. SHm will detect it as a "gap" so automatic refinement will be also done in these cases. If you are on the other side of the domain (fluid), then then you have to use the feature refinement.

March 14, 2019, 04:40		#3
Bdew8556 Senior Member Brett Join Date: May 2013 Posts: 212 Rep Power: 13	Thanks simrego! I've been having some troubles with sHM. At the moment I'm trying to mesh an airfoil within a 3D domain where the foil edges dont touch the sides of the domain. Do you know of any example sHMDict files that could be a good template?

March 14, 2019, 04:48		#4
simrego Senior Member anonymous Join Date: Jan 2016 Posts: 416 Rep Power: 14	In the tutorials there is a mesh folder and a SHM folder in it where you can find examples, or check the motorBike tutorial. Depending on the version you are using some explanation can be found here: OFv6 (FOUNDATION version): https://cfd.direct/openfoam/user-gui...snappyhexmesh/ or v1812 (esi group version): https://openfoam.com/documentation/g...pyhexmesh.html What works in OF 6 it is usually also working in the esi version, but not vice-versa. And the esi version has more functionality (I think gap detection is not implemented in OF6 but I'm not 100% sure, also different mesh smoothing for layer insertion, etc.).