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ignored parts of geometry during refinement

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Old   September 18, 2012, 07:37
Default ignored parts of geometry during refinement
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Elo´se
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Hello,

A part of my geometry is composed of poles, for which I impose a given refinement level. Most of the poles are refined as expected, but some of them are ignored in the refinement stage. They end up with very large resolution (see attached image).
Do you know how I can avoid this?

Remarks:
- The maximum amount of cells is not reached during castellation step.
- minRefinementCells was set to 0 without any impact.
- all the poles are part of the same STL input file and should therefore be treated the same way.

Thanks for your help,
Elo´se
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Old   September 20, 2012, 08:26
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no idea?
I must say it is not really critical in my mesh, but I'm curious to find out its reason
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Old   September 25, 2012, 05:21
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Tobias Holzmann
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Quote:
Originally Posted by Eloise View Post
no idea?
I must say it is not really critical in my mesh, but I'm curious to find out its reason
Hey ...
maybe your sHM stop refining couse of reaching "maxGloballCells". So if your mesh reaches that limit, sHM stop direct without refining other zone.

Set that value higher - maybe that is the solution for your problem.
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Old   September 25, 2012, 06:15
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Hi Tobi,
The maxGlobalCells is not the problem, I've already checked that point.
Thanks anyway
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Old   September 25, 2012, 06:39
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Karl-Johan Nogenmyr
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Hi,

did you specify surface refinement or feature line refinement?

K
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Old   September 26, 2012, 09:23
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Hi Karl,

Surface refinement is the same for all the geometry as it comes from a single STL file.
But the feature edges refinement did the trick. All geometry is refined, and mesh quality was slightly improved. However, I haven't used the "snap to feature edges" option as this results in the following error message from sHM "Did not succesfully snap mesh. Giving up."

Thanks,
Elo´se
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Old   September 28, 2012, 01:45
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I see... I was asking since there is a bug which causes snappy to ignore some refining specified on feature lines:

http://www.openfoam.org/mantisbt/view.php?id=552

Since you only specified surface refinement, you should not be affected by that.

I'd guess the error message you get is because snappy could not snap to the surface while maintaining good mesh quality... playing around with settings may help:

http://openfoamwiki.net/index.php/SnappyHexMesh

Good luck,
K
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Old   September 28, 2012, 02:36
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Hi Karl,

I am not especially looking for snapping at those feature edges so I will leave it as it is. If I had to snap, I should first increase the refinement level, but then my mesh would get very large. I have to avoid that.

I am also aware of this bug in 2.0 as I have this issue in another location in my geometry. I'm trying to upgrade to 2.1 but it is not as easy as it looks like... I hope I will soon be a part of the "2.1 foamers community"

Elo´se
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