CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > OpenFOAM Mesh Utilities

edgeGrading

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

Reply
 
LinkBack Thread Tools Display Modes
Old   March 16, 2016, 13:50
Question edgeGrading
  #1
New Member
 
Jack_Landis's Avatar
 
Join Date: Feb 2016
Posts: 23
Rep Power: 2
Jack_Landis is on a distinguished road
Hi everyone,

I'm a beginner with openFOAM.

I have some problem to understand edgeGrading...I understood that I have to define the expansion ratio for each edge of the hexahedron. They are grouped along the three directions, so the first 4 edges are all the edges along X1 and so on for X2 and X3. The thing I can't understand is to which edge corresponds each number in the parenthesis . How are they ordered?

Thanks!
Jack_Landis is offline   Reply With Quote

Old   March 17, 2016, 22:39
Default
  #2
Senior Member
 
Join Date: Aug 2013
Posts: 227
Rep Power: 6
Antimony is on a distinguished road
Hi,

I would think they are ordered from 0 to 11 within the parenthesis with edge 0 etc. being defined as described here:

http://cfd.direct/openfoam/user-guide/blockMesh/

No?

Cheers,
Antimony
Antimony is offline   Reply With Quote

Old   March 18, 2016, 06:51
Default
  #3
New Member
 
Jack_Landis's Avatar
 
Join Date: Feb 2016
Posts: 23
Rep Power: 2
Jack_Landis is on a distinguished road
Hi Antimony!

Thank you for your reply! You're right. In my case, I had this error:

Inconsistent number of faces between block pair 2 and 7

and I thought it was due to grading, but it wasn't. The problem was the way I had defined the blocks: I didn't take care of the order of vertices in the hex(...), but now I understood that this order defines axis X1, X2 and X3 for each block.

Is it correct?
Jack_Landis is offline   Reply With Quote

Old   March 19, 2016, 11:28
Default
  #4
Senior Member
 
Join Date: Aug 2013
Posts: 227
Rep Power: 6
Antimony is on a distinguished road
Hi,

Generally if you have inconsistent number of faces, it usually means that the number of cells between the different blocks has a mismatch. Unless you are duplicating vertices (and therefore duplicating edges), the common edge shared by two blocks will need to have the same number of divisions.

And yes, the ordering of the vertices determines the axes and consequently, whether or not your cells are "proper". In case your order of vertices is wrong, you will end up with cells with negative volumes which blockMesh will report during its run.

Hope this helps.

Cheers,
Antimony
Antimony 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
Multi-grading: Inconsistent point locations between blocks Flowkersma OpenFOAM Native Meshers: blockMesh 2 August 2, 2015 14:34
Problems simulating deformation sur4j OpenFOAM 0 January 26, 2014 10:07
EdgeGrading changes geomety anita OpenFOAM Native Meshers: blockMesh 7 March 2, 2009 12:16
BlockMeshrefineMesh bug iagmanu OpenFOAM Bugs 0 February 25, 2008 09:49


All times are GMT -4. The time now is 19:08.