CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Open Source Meshers: Gmsh, Netgen, CGNS, ...

cfMesh edge detection (solved!)

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

Like Tree1Likes
  • 1 Post By franjo_j

Reply
 
LinkBack Thread Tools Display Modes
Old   December 1, 2015, 10:15
Default cfMesh edge detection (solved!)
  #1
Member
 
Pekka Pasanen
Join Date: Feb 2012
Location: Finland
Posts: 74
Rep Power: 6
zordiack is on a distinguished road
Hi, lately I've been having a lot of trouble with cfMesh edge detection. The mesh is fine otherwise, but sharp edges are not conformed or "snapped". I have the original geometry in a file whole.stl, and I'm using the following command to detect edges:

Code:
surfaceFeatureEdges -angle 120 whole.stl whole.fms
The file whole.fms is then used as an input for cfMesh meshDict. I've attached a picture to show the problem, where the surface file whole.stl and generated mesh are shown in paraview.



Any help? Is this the correct way to use edge detection with cfMesh or is there a better way? I don't recall having this problem before, but I might just have been lucky. I'm using OpenFOAM-dev with cfMesh 1.1.1.

Last edited by zordiack; December 1, 2015 at 10:55. Reason: corrected title
zordiack is offline   Reply With Quote

Old   December 1, 2015, 10:51
Default
  #2
Member
 
Pekka Pasanen
Join Date: Feb 2012
Location: Finland
Posts: 74
Rep Power: 6
zordiack is on a distinguished road
Okay this is (again) going to be one those post where I correct myself. It turns out I've been using the included angle option the wrong way around. It doesn't work the same way as in snappyHexMesh. So if you want to include i.e. all edges with at least 90 degree angle, you should use a SMALLER than 90 degrees angle specification with surfaceFeatureEdges, or just use the default (which is 45 degrees):

Code:
surfaceFeatureEdges whole.stl whole.fms
I'm happy to report that the edge detection is working again, when I use it correctly Here is the same mesh with correct edge detection:

zordiack is offline   Reply With Quote

Old   December 5, 2015, 17:12
Default
  #3
Senior Member
 
Franjo Juretic
Join Date: Aug 2011
Location: Velika Gorica, Croatia
Posts: 106
Rep Power: 8
franjo_j is on a distinguished road
Send a message via Skype™ to franjo_j
You can inspect the feature edges by using:

FMSToSurface <inputSurfaceMesh>.fms <outputSurface> -exportFeatureEdges

-exportFeatureEdges writes feature edges in a vtk file, which you can visualize in ParaView.
zordiack likes this.
__________________
Principal Developer of cfMesh
www.cfmesh.com
Social media: LinkedIn, Twitter, YouTube, Google+, Facebook, Pinterest
franjo_j is offline   Reply With Quote

Old   February 4, 2016, 15:43
Default
  #4
New Member
 
Nila
Join Date: Oct 2014
Posts: 24
Rep Power: 3
zannatul is on a distinguished road
Can you please tell me why it is saying to me that surfaceFeatureEdges command not found?
zannatul is offline   Reply With Quote

Old   February 5, 2016, 07:31
Default
  #5
Senior Member
 
Franjo Juretic
Join Date: Aug 2011
Location: Velika Gorica, Croatia
Posts: 106
Rep Power: 8
franjo_j is on a distinguished road
Send a message via Skype™ to franjo_j
Hi,

Quote:
Originally Posted by zannatul View Post
Can you please tell me why it is saying to me that surfaceFeatureEdges command not found?
surfaceFeatureEdges is part of cfMesh. It seems to me that you do not have cfMesh available in your environment or your OF environment is not set up correctly.
__________________
Principal Developer of cfMesh
www.cfmesh.com
Social media: LinkedIn, Twitter, YouTube, Google+, Facebook, Pinterest
franjo_j is offline   Reply With Quote

Old   February 5, 2016, 14:08
Smile
  #6
New Member
 
Nila
Join Date: Oct 2014
Posts: 24
Rep Power: 3
zannatul is on a distinguished road
Quote:
Originally Posted by franjo_j View Post
Hi,



surfaceFeatureEdges is part of cfMesh. It seems to me that you do not have cfMesh available in your environment or your OF environment is not set up correctly.
Yes may be that is the thing. Thank you for your response
zannatul 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
Problem CfMesh 2D Mesh Clmkite OpenFOAM Native Meshers: snappyHexMesh and Others 0 September 24, 2015 08:52
how to set periodic boundary conditions Ganesh FLUENT 13 January 22, 2014 05:11
Ansys CFX Turbogrid, Problem with blade leading edge sitting on hub at inlet Irondome CFX 2 January 20, 2014 19:26
[ICEM] Problem in Edge meshing Daniel_Khazaei ANSYS Meshing & Geometry 1 October 17, 2013 06:45
Through-Flow solver, Leading-Trailing edge problem Menander Main CFD Forum 0 May 14, 2008 18:14


All times are GMT -4. The time now is 12:25.