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Wrong surface normals with SHM's baffle feature on varying blockMeshDict description

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Old   January 20, 2014, 18:15
Exclamation Wrong surface normals with SHM's baffle feature on varying blockMeshDict description
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Ripudaman Manchanda
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Dear Foamers,

I have posted my problem on the bug reporting system here - http://www.openfoam.org/mantisbt/view.php?id=1131.

One of the managers replied and said that he was not able to reproduce the problem. I am unable to diagnose what I am doing wrong. Can you please help me?

I am creating a circular baffle (radius = 5, center = 0,0,0) using SHM. The baffle is in the YZ plane. The two faces of the normal after snapping should have normals in the opposite directions. I found that this varies with a small change in the blockMeshDict file.

Keeping everything else same if I increase the size of my blockMesh dict in the +X direction (increasing the gridblocks in +X direction proportionately) I find that the surface normals on the circular baffle (ff and ff_slave) become randomly oriented.

I have attached two cases. Sneddon_50_25_25 works perfectly while Sneddon_100_25_25 does not.
The first case has a box with dimensions (-100,-50,-50) to (100,50,50) with 50,25,25 gridblocks in X,Y and Z directions respectively.
The second case has the box with dimensions (-100,-50,-50) to (300,50,50) with 100,25,25 gridblocks in X,Y and Z directions respectively.
In both cases the disc/baffle is located at 0,0,0 and oriented in the YZ plane.

Can you please confirm if you can reproduce a random arrangement in the cell normals on the ff patch in the X direction? The normals on one side of the patch should ideally be uniformly either (1,0,0) or (-1,0,0). I get a mixed bag for the second case.

Thanks for your help.

Ripu
Attached Files
File Type: gz Sneddon_50_25_25.tar.gz (7.6 KB, 0 views)
File Type: gz Sneddon_100_25_25.tar.gz (7.6 KB, 0 views)
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Old   January 26, 2014, 10:35
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Bruno Santos
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For future readers: this problem seems to have been already solved, or at least the bug has been reported as already fixed and confirmed on the indicated bug report.
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Old   January 26, 2014, 14:43
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Ripudaman Manchanda
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The problem was solved by using an updated version of OpenFOAM 2.2.x form the repository.
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baffle, fracture, snappyhexmesh, surface normals

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