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

Fluent Solution Residuals

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

Reply
 
LinkBack Thread Tools Display Modes
Old   September 12, 2003, 14:34
Default Fluent Solution Residuals
  #1
RC
Guest
 
Posts: n/a
Hello,

I am solving a single phase, unsteady, rotating flow in a cylinder---just continuity and momentum equations.

What exactly does it mean when Fluent tells me my unsteady solution has "converged" if I set my residuals to say < 1E-5? I mean when I go to check continuity at a point in my model there are many places where it is not satisfied anywhere close to 1E-5. Is this an indication that my mesh is too coarse at these locations or perhaps I have chosen my inlet and exit boundary conditions inappropriately.

Any insight would be much appreciated!

  Reply With Quote

Old   September 12, 2003, 20:43
Default Re: Fluent Solution Residuals
  #2
dw
Guest
 
Posts: n/a
hi, if you look carefully at the manual(paper or electronic), you will find that there are different definitions of residual, which will depend on the solver type firstly, i.e. segerated and coupled are different. Be sure to check what kind of solver and residual definition you are using.
  Reply With Quote

Old   September 30, 2003, 02:34
Default Re: Fluent Solution Residuals
  #3
Alamgir
Guest
 
Posts: n/a
Your solution is converged that means results are almost satisfied the citerion u set for the simulation. This residuls less than 1e-5 is only the difference between your present value and previous value. If you are not lucky enough, u could see you are diverging from the next iterations. This is called instability of residual. It may happen for unsteady turbulence case.

Alamgir
  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
Fluent jobs through pbs ibnkureshi FLUENT 5 June 9, 2011 13:43
Problem in Fluent Solution - Waves on Surface Contour Richard_CFD FLUENT 0 September 8, 2010 14:39
Accuracy and convergence pawan1989 FLUENT 5 April 15, 2010 17:17
Could anybody help me see this error and give help liugx212 OpenFOAM Running, Solving & CFD 3 January 4, 2006 19:07
Solution file to be used in Fluent asif FLUENT 5 July 9, 2003 09:41


All times are GMT -4. The time now is 01:57.