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[snappyHexMesh] Missing elements near surface with snappyHexMesh |
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September 16, 2010, 18:27 |
Missing elements near surface with snappyHexMesh
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#1 |
Member
Jean-Michel FONTAINE
Join Date: Aug 2009
Location: Orleans - France
Posts: 55
Rep Power: 17 |
Hello everybody
I'm struggling to solve mesh quality problems on the surface of my model : small holes due to missing elements near the model surface. These holes always occur near transition between patches with different levels I attached - a clipped view of flaw in volume - a view of the surface (from inside the volume) with 3 flaws - the snappyHexMeshDict Is the smoothness of the mesh at the surface normal ? I think that it is poor... I run OF1.7.1 on 64 bit Linux, compiled from sources Any tip would be appreciated Regards J-Michel |
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September 18, 2010, 07:18 |
Missing cells near surface with snappyHexMesh
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#2 |
Member
Jean-Michel FONTAINE
Join Date: Aug 2009
Location: Orleans - France
Posts: 55
Rep Power: 17 |
Hello
I go on investigating This problem only occurs when surface is tilted compared with backgroung hex mesh. I tried 10 and 20 degrees slope. (image attached at 20 degrees) With surface parallel to background mesh, snappy mesh is smooth (image attached) The problem is the same with prebuild OF1.6 32 bits Best wishes jean-Michel |
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September 23, 2010, 00:07 |
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#3 |
Senior Member
Join Date: Mar 2009
Location: My oyster
Posts: 124
Rep Power: 17 |
Hi Jean-Michel,
Is your geometry smooth enough at these locations? Maybe you could increase the tessellation at these locations in the stl file. It could be a defect in the geometry file. Otherwise it seems to be a snapping problem. How about increasing nSmoothPatch? Try running checkMesh -latestTime to see if these elements are not contorted. Ziad |
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September 27, 2010, 19:48 |
Missing cells near surface with snappyHexMesh
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#4 |
Member
Jean-Michel FONTAINE
Join Date: Aug 2009
Location: Orleans - France
Posts: 55
Rep Power: 17 |
Hi Ziad
Thanks for your answer I tried increasing nSmoothPatch without result. But then I tried systematic modifications of other Snappy parameters, and finally I found that maxConcave = 90 (instead of 30) solved my problem Best wishes Jean-Michel |
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September 27, 2010, 19:55 |
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#5 | |
Senior Member
Join Date: Mar 2009
Location: My oyster
Posts: 124
Rep Power: 17 |
Quote:
Thanks for posting the solution Jean-Michel. It's funny but the maxConcave parameter seems to be quite influent on the mesh. I managed to get a mesh without the ragged/jagged edges by reducing maxConcave to 1.0 and it's good to know that it can also fix this type of problems. Cheers, Ziad |
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August 27, 2013, 10:25 |
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#6 |
New Member
Stylianos Kyriacou
Join Date: Mar 2010
Location: Cyprus - Athens - Austria - Zurich
Posts: 27
Rep Power: 16 |
Thanks for the help guys
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November 10, 2017, 15:16 |
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#7 |
Member
Amir Abbas Aliabadi
Join Date: Mar 2013
Posts: 33
Rep Power: 13 |
Hello Dear All,
I also found that inserting a maxConcave = 90 in the meshQualityControls successfully achieves the snapping part of mesh generations. Thank You, Amir A. Aliabadi |
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Tags |
hole, quality, snappyhexmesh, surfaces |
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