[snappyHexMesh] snappyHexMesh does not snap everywhere

flowris · February 11, 2011, 05:47

Hello,

I am trying to make a mesh around a polyhedron that approximates a ball, using snappyHexMesh in 1.7.1. I try to snap the surface, but this only works out around the "equator" (xy-plane). Near the "poles" the mesh remains blocky and does not follow the surface.

What did I forget?

flowman · February 13, 2011, 17:56

It's not snapping to the surface because you have the refinement turned off.

In the refinementSurfaces section set level (1 1) to level (1 2) and in the refinementRegions section set levels ((1e5 0)) to levels ((1e5 2))

flowris · February 14, 2011, 02:12

I am sorry, but that does not help. I thought that anything that had to do with the snapping action, was in the snapControls subdictionary.

giovanidiniz · June 4, 2013, 14:23

Flowris,

I am having the exact same problem wit my geometry. Did you figure out what was going on?

kwardle · June 5, 2013, 13:52

Hello ~ this does seem like odd behavior and just looking at your dict file I don't see any obvious problems. However, you are using an old version of OF, one in which snappy was still relatively new. Many developments, especially with surface/feature snapping, have happened since then. I would suggest that you try it with a new(er) version and verify that you still have this problem.
-Kent

mihaipruna · June 11, 2013, 10:40

might sound counterintuitive but try to decrease the maximum global cells.

giovanidiniz · June 11, 2013, 10:47

Hi,

So, I figured out what the problem was.

In the blockMeshDict I had set the inlet and outlet patches as "empty".
As soon as I set them as "patches", everything worked out.

Thanks for the reply, though!

Cheers

SeaFD · February 17, 2019, 05:17

Thank you!!!
I had the same problem and have tried the suggestions in all the other threads and nothing was working. Seems it was as simple, though not obvious, as changing one of my boundaries from 'empty' to 'patch' and it works fine now.

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February 13, 2011, 17:56		#2
flowman New Member Aidan Join Date: Apr 2010 Posts: 18 Rep Power: 16	It's not snapping to the surface because you have the refinement turned off. In the refinementSurfaces section set level (1 1) to level (1 2) and in the refinementRegions section set levels ((1e5 0)) to levels ((1e5 2))

February 14, 2011, 02:12		#3
flowris Senior Member Join Date: Apr 2010 Posts: 151 Rep Power: 16	I am sorry, but that does not help. I thought that anything that had to do with the snapping action, was in the snapControls subdictionary.

June 4, 2013, 14:23		#4
giovanidiniz New Member Giovani Diniz Join Date: Jun 2013 Location: Boston Posts: 13 Rep Power: 12	Flowris, I am having the exact same problem wit my geometry. Did you figure out what was going on?

June 5, 2013, 13:52		#5
kwardle Senior Member Kent Wardle Join Date: Mar 2009 Location: Illinois, USA Posts: 219 Rep Power: 21	Hello ~ this does seem like odd behavior and just looking at your dict file I don't see any obvious problems. However, you are using an old version of OF, one in which snappy was still relatively new. Many developments, especially with surface/feature snapping, have happened since then. I would suggest that you try it with a new(er) version and verify that you still have this problem. -Kent

June 11, 2013, 10:40		#6
mihaipruna Senior Member Mihai Pruna Join Date: Apr 2010 Location: Boston Posts: 195 Rep Power: 16	might sound counterintuitive but try to decrease the maximum global cells.

June 11, 2013, 10:47		#7
giovanidiniz New Member Giovani Diniz Join Date: Jun 2013 Location: Boston Posts: 13 Rep Power: 12	Hi, So, I figured out what the problem was. In the blockMeshDict I had set the inlet and outlet patches as "empty". As soon as I set them as "patches", everything worked out. Thanks for the reply, though! Cheers

February 17, 2019, 05:17		#8
SeaFD New Member Join Date: Mar 2016 Posts: 2 Rep Power: 0	Thank you!!! I had the same problem and have tried the suggestions in all the other threads and nothing was working. Seems it was as simple, though not obvious, as changing one of my boundaries from 'empty' to 'patch' and it works fine now.