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

Gaps in between surfaces

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

Reply
 
LinkBack Thread Tools Display Modes
Old   May 28, 2006, 16:15
Default Gaps in between surfaces
  #1
Vidya Raja
Guest
 
Posts: n/a
Hi,

the model that I'm trying to mesh has some small gaps (of the order of 1E-6) at the sites where two surfaces are being merged. I don't want any flow through those gaps. The gaps arose when I did the modeling in Pro/E. Will GAMBIT or Fluent detect those gaps and create problems?

I'm wondering about this because I'm having problems meshing my geometry and GAMBIT does not specificaaly point out to this while giving errors. But during the analysis, will FLUENT detect gaps of such small magnitudes and give erroneous results?

Thanks, Vidya
  Reply With Quote

Old   May 28, 2006, 21:09
Default Re: Gaps in between surfaces
  #2
jiangxuxu
Guest
 
Posts: n/a
Hi,

As far as I know, Gambit and Fluent merely detect the least distance of 0.000001. If the gap is smaller than 0.000001, Gambit and Fluent can't solve.

  Reply With Quote

Old   May 28, 2006, 21:18
Default Re: Gaps in between surfaces
  #3
Vidya Raja
Guest
 
Posts: n/a
Hi,

What do you mean by "Can't solve"? Please explain.

The gap that I detect in Pro/E is about 6.4548*10E-6. So will I get wrong results from my FLUENT analyses? Will there be problems in meshing? I'm trying to fix the problem in Pro/E itself, but am unable to find a solution.

If I go ahead with what I have right now, will GAMBIT and Fluent blow up?

Thnaks, Vidya
  Reply With Quote

Old   May 28, 2006, 21:31
Default Re: Gaps in between surfaces
  #4
jiangxuxu
Guest
 
Posts: n/a
Hi, 'can't solve' means them can't tell aparat(distinguish). 6.4548*10E-6 means 0.000064548. So Fluent and Gambit can compute.
  Reply With Quote

Old   May 29, 2006, 08:30
Default Re: Gaps in between surfaces
  #5
Kasper Skriver
Guest
 
Posts: n/a
Ok, GAMBIT operates with an accuracy of 1E-06 in any kind of units.

Let's say you have a cad(SAT) drawing with a gap below 1E-06, then GAMBIT will not see the gap - and you can continue with no mesh problems.

If the gap is above 1E-06 you got a problem in GAMBIT and need to take care of the gap in some way. Cleanup could be a solution, I would zoom in and detect the error visualy and then create a new volume without gaps.

I don't know if you can change the 1E-06 tolerance in GAMBIT or maybe in your cad program.

/Kasper@DK
  Reply With Quote

Old   May 29, 2006, 09:37
Default Re: Gaps in between surfaces
  #6
Vidya Raja
Guest
 
Posts: n/a
Thanks Jiangxuxu and Kasper. I'll try your suggestions and see how it works.

Cheers, Vidya
  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
how to get forces on Iso-Clip Surfaces and How to get forces in cylindrical coordinat CFD XUE FLUENT 3 March 18, 2015 04:28
Importing or Creating 2D Flat Surfaces into CFX Sam CFX 5 March 30, 2013 12:11
Exporting surfaces inside the control volume (interior) bigmoneylou ANSYS Meshing & Geometry 1 January 8, 2011 17:16
problemes modelling surfaces with snappyhexmesh gija79 OpenFOAM 5 June 30, 2010 13:50
Faceted surfaces in ICEM Chriss Main CFD Forum 1 May 6, 2008 15:18


All times are GMT -4. The time now is 02:52.