CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > CD-adapco

volume source problems in ccm v3

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

Reply
 
LinkBack Thread Tools Display Modes
Old   April 8, 2008, 15:51
Default volume source problems in ccm v3
  #1
tom
Guest
 
Posts: n/a
Hi all,

I add a volume source in a region in star-ccm+ v3, then I generate the mesh. After this, I see that the mesh generated inside the volume source has a strange pattern to it, and it is also of very poor quality around region boundaries. This doesn't seem to be evident in earlier versions. Has anyone experienced this? Is there some way to recitfy this, or do I need to go back to earlier versions.

Tom
  Reply With Quote

Old   April 9, 2008, 01:09
Default Re: volume source problems in ccm v3
  #2
Andrew
Guest
 
Posts: n/a
Which mesh models are you implementing?
  Reply With Quote

Old   April 9, 2008, 03:12
Default Re: volume source problems in ccm v3
  #3
tom
Guest
 
Posts: n/a
This happens with both tetrahedral and poly mesh.

I use polyhedral/tetrahedral, prism layer, surface remesher models. Due you think that the cause is a certain combination of models? This effect happens also in v2.10 but not earlier versions than that, so I don't think it is due to the introduction of the extruder model.

Thanks
  Reply With Quote

Old   April 9, 2008, 09:22
Default Re: volume source problems in ccm v3
  #4
Jim
Guest
 
Posts: n/a
I don't see how it can be anything to do with the extruder unless you are turning it on and using it. The volume sources did change in 2.10 so that you get a more even distribution of cells (I think I read that in the release notes you might want to check it out) what is the face validity of the cells and do they make the run diverge?
  Reply With Quote

Old   April 10, 2008, 11:52
Default Re: volume source problems in ccm v3
  #5
tom
Guest
 
Posts: n/a
Hi Jim,

Then I guess the guys at Adapco have a strange definition of uniformity. To me, if they were to properly enhance the uniformity of mesh then all adjacent cells, within the volume source, should be of the same size with the only exceptions being the boundary cells. Instead, now, for every 4 adjacent of equal size there is a small one squeezed in at the corners. This cell is over 2 times smaller, and thats why I get an odd pattern.

Is this a more prefered way of meshing, otherwise I don't understand why they have changed this.

I prefer the older way, at least I have more control over the "general" cell size within the volume source.

Thanks, Tom
  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
Problems while compiling source sahas OpenFOAM Installation 2 October 20, 2007 12:47
Problems with negative volume cells Shashank CD-adapco 2 April 4, 2007 18:24
momentum source: continuity problems Johannes Radke CFX 2 December 17, 2004 05:21
source term problems!!! Christian FLUENT 0 June 10, 2003 10:33
Problems with Volume Fraction Richard Pemberton CFX 1 May 27, 2001 10:49


All times are GMT -4. The time now is 16:11.