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

2D External Aerodynamics

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

Reply
 
LinkBack Thread Tools Display Modes
Old   August 19, 2005, 20:13
Default 2D External Aerodynamics
  #1
Miqdad
Guest
 
Posts: n/a
Dear All,

Can some one suggest the best model setup while performing an external aerodynamics problem in Fluent 2D.

I am simulating airflow over a wing at subsonic speeds. I have used the Splart Allarmas turbulence model but cannot decide which solver to go for, I mean Implicit or Explicit. Secondly, I am plotting Cd and Cl while its solving and to be honest they are all over the place. I dont see any sign of convergence.

Any suggestions on what I have done wrong?

Thanks in advance. Miqdad
  Reply With Quote

Old   August 19, 2005, 20:23
Default Re: 2D External Aerodynamics
  #2
Sham
Guest
 
Posts: n/a
Are you using steady or unsteady solver?

Sham.
  Reply With Quote

Old   August 20, 2005, 08:28
Default Re: 2D External Aerodynamics
  #3
Miqdad
Guest
 
Posts: n/a
Well, its not time dependent if that is what you are after. Its a steady state analysis.
  Reply With Quote

Old   August 20, 2005, 15:49
Default Re: 2D External Aerodynamics
  #4
razvan
Guest
 
Posts: n/a
If you have been using coupled solver, switch to segregated solver and see what happens. Usually, if the velocities are low in most of the calculation domain, segregated solver will certainly behave much better. I simply don't see any other reason for such a simple analisys to not converge. Although, if you are simulating a high angle of attack flow, beyond the critical incidence of your wing, vortex shedding will surely give you difficulties and you will not obtain a steady solution.

Best wishes, Razvan
  Reply With Quote

Old   August 22, 2005, 15:16
Default Re: 2D External Aerodynamics
  #5
helper
Guest
 
Posts: n/a
If the case is set up as a steady problem, use either coupled implicit solver or segregated solver. When you see lack of convergence, try smaller under-relaxation factors (in the segregated solver) or CFL number (in the coupled solver).
  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
CGNS Compiling Diego Main CFD Forum 17 December 21, 2014 02:40
DOCUMENT EXTERNAL AERODYNAMICS Erdem CD-adapco 4 October 12, 2010 09:23
DOCUMENT EXTERNAL AERODYNAMICS Erdem CFX 0 March 4, 2006 18:48
DOCUMENT EXTERNAL AERODYNAMICS Erdem Main CFD Forum 0 March 4, 2006 18:48
DOCUMENTS EXTERNAL AERODYNAMICS Erdem FLUENT 0 March 2, 2006 06:03


All times are GMT -4. The time now is 08:10.