CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > OpenFOAM Native Meshers: snappyHexMesh and Others

snappyHexMesh layers at the corner missing

Register Blogs Members List Search Today's Posts Mark Forums Read

Reply
 
LinkBack Thread Tools Display Modes
Old   February 11, 2014, 09:37
Default snappyHexMesh layers at the corner missing
  #1
Member
 
Cong
Join Date: Nov 2012
Posts: 77
Rep Power: 4
wc34071209 is on a distinguished road
Hi Foamers,,

I am using sHM to generate mesh, but usually at the corners the layers are missing. Could anybody tell me how to solve this problem?
wc34071209 is offline   Reply With Quote

Old   February 11, 2014, 11:41
Default
  #2
Senior Member
 
chegdan's Avatar
 
Daniel P. Combest
Join Date: Mar 2009
Location: St. Louis, USA
Posts: 538
Rep Power: 18
chegdan will become famous soon enough
When layers are inserted into the mesh, the mesh quality is probably poor and the layers are collapsed. You could
  • make your overall base mesh smaller or bump your refinement level in the corners up a bit
  • Use distance refinement from that surface to refine cells prior to the layer insertion to make small cells so that the mesh quality is not poor enough to cause layer collapse
  • or you could adjust the featureAngle entry in the addlayerControls section to be something like 180. See this presentation for more details, specifically slide44

You may want to start with the last one first....but be careful changing too many things at once to get a desired result. Good Luck!
__________________
Dan

Find me on twitter @dancombest and LinkedIn
chegdan is offline   Reply With Quote

Old   February 11, 2014, 16:17
Default
  #3
Member
 
Cong
Join Date: Nov 2012
Posts: 77
Rep Power: 4
wc34071209 is on a distinguished road
Quote:
Originally Posted by chegdan View Post
When layers are inserted into the mesh, the mesh quality is probably poor and the layers are collapsed. You could
  • make your overall base mesh smaller or bump your refinement level in the corners up a bit
  • Use distance refinement from that surface to refine cells prior to the layer insertion to make small cells so that the mesh quality is not poor enough to cause layer collapse
  • or you could adjust the featureAngle entry in the addlayerControls section to be something like 180. See this presentation for more details, specifically slide44

You may want to start with the last one first....but be careful changing too many things at once to get a desired result. Good Luck!
Thank you very much.

I have also found that the layers insertion in sHM is very unstable. When I have nSurfaceLayers = 10 then it seems everything is OK, but if I use 15 layers, no layer is inserted. I am totally confused.

Could you provide some hints?
wc34071209 is offline   Reply With Quote

Old   February 12, 2014, 12:32
Default
  #4
Senior Member
 
chegdan's Avatar
 
Daniel P. Combest
Join Date: Mar 2009
Location: St. Louis, USA
Posts: 538
Rep Power: 18
chegdan will become famous soon enough
My only hint is that you should slowly add more layers rather than jumping to 150 percent more than where previously successful. You can also try to create a very uniform group of cells where you want to insert layers and this may improve it. Usually, shrinking your base mesh solves many problems with snappyHexMesh. There are many adjustments you can make to the quality measurements but that can make things worse if you aren't careful.
__________________
Dan

Find me on twitter @dancombest and LinkedIn
chegdan is offline   Reply With Quote

Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
snappyHexMesh Boundary Layer at Corner panpanzhong OpenFOAM Native Meshers: snappyHexMesh and Others 4 October 27, 2014 05:31
2D snappyHexMesh with layers grjmell OpenFOAM Native Meshers: snappyHexMesh and Others 2 May 27, 2013 12:00
Adding layers goes wrong with SnappyHexMesh Elise OpenFOAM Native Meshers: snappyHexMesh and Others 1 April 22, 2013 02:32
SnappyHexMesh doesn't succeed in adding several layers eti0123456789 OpenFOAM Native Meshers: snappyHexMesh and Others 5 April 9, 2013 02:36
errors when installing openfoam2.1 on ubuntu12.o4 hewei OpenFOAM Installation 5 May 29, 2012 07:43


All times are GMT -4. The time now is 15:19.