[snappyHexMesh] Snappy creates a bumpy surface

swin-joe · November 6, 2015, 08:58

Hi FOAMers,

I'm trying to get a good mesh with snappy. Unfortunately the results are not so satisfying. There are some strange dips in the mesh. In addition the snappying to some featureEdges doesn't work, as well. Following some threads, I play with the meshQualityControls. I also used different featureEdges sources like the .eMesh, .extendedFeatureEdgeMesh or the direct export from paraView.

Thanks for the help
Andi

swin-joe · November 8, 2015, 03:58

Any ideas?

regards Andi

wyldckat · November 8, 2015, 06:05

Two quick questions:

Have you tried following the instructions given here: http://openfoamwiki.net/index.php/FA...is_in_ParaView
What OpenFOAM version are you using?

swin-joe · November 8, 2015, 09:10

Hello Bruno,

thank you for the response

. I'm using openFOAM 2.3.0.
You think it's a visualization problem?

Regards Andi

wyldckat · November 8, 2015, 10:25

Quick answer: Yes, I suspect that part of the problems are due to a visualization problem. Check this bug report: http://www.openfoam.org/mantisbt/view.php?id=1633
Notice that the image "before_fix.png" is similar to some of the flaws you're seeing. If I'm not mistaken, this issue is already fixed in OpenFOAM 2.3.1.

In addition, sometimes more complex cells are not properly decomposed into tetrahedral cells, which could account for some of the flaws you're seeing. Which is why I mentioned the instructions for mesh visual inspection in ParaView.

swin-joe · November 9, 2015, 07:20

Thank you for the help.
I installed OpenFOM-3.0.0. The mesh looks pretty good, now.

Regards Andi

November 8, 2015, 03:58	Snappy creates a bumpy surface	#2
swin-joe New Member Andi Join Date: Feb 2014 Location: Berlin Posts: 6 Rep Power: 12	Any ideas? regards Andi

November 8, 2015, 06:05		#3
wyldckat Retired Super Moderator Bruno Santos Join Date: Mar 2009 Location: Lisbon, Portugal Posts: 10,982 Blog Entries: 45 Rep Power: 128	Two quick questions: Have you tried following the instructions given here: http://openfoamwiki.net/index.php/FA...is_in_ParaView What OpenFOAM version are you using? __________________ OpenFOAM: FAQ \| Getting started Forum: How to get help, to post code/output and forum guide Read this before sending me PM

November 8, 2015, 10:25		#5
wyldckat Retired Super Moderator Bruno Santos Join Date: Mar 2009 Location: Lisbon, Portugal Posts: 10,982 Blog Entries: 45 Rep Power: 128	Quick answer: Yes, I suspect that part of the problems are due to a visualization problem. Check this bug report: http://www.openfoam.org/mantisbt/view.php?id=1633 Notice that the image "before_fix.png" is similar to some of the flaws you're seeing. If I'm not mistaken, this issue is already fixed in OpenFOAM 2.3.1. In addition, sometimes more complex cells are not properly decomposed into tetrahedral cells, which could account for some of the flaws you're seeing. Which is why I mentioned the instructions for mesh visual inspection in ParaView. swin-joe likes this.

November 9, 2015, 07:20		#6
swin-joe New Member Andi Join Date: Feb 2014 Location: Berlin Posts: 6 Rep Power: 12	Thank you for the help. I installed OpenFOM-3.0.0. The mesh looks pretty good, now. Regards Andi wyldckat likes this.

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November 8, 2015, 09:10		#4
swin-joe New Member Andi Join Date: Feb 2014 Location: Berlin Posts: 6 Rep Power: 12	Hello Bruno, thank you for the response . I'm using openFOAM 2.3.0. You think it's a visualization problem? Regards Andi