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

unchanged residuals and changing results

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   February 15, 2019, 22:08
Default unchanged residuals and changing results
  #1
Senior Member
 
Weiqiang Liu
Join Date: Feb 2018
Posts: 278
Rep Power: 9
Weiqiang Liu is on a distinguished road
hi all,

In a case I am doing, all the residuals are below 1e-5 and keeps unchanged for a very long time. However, all the results like temperature contour or surface coverage profile keeps changing. Is it normal?

As far as I am concerned, if all the residuals are constant, then all the results should keep unchanged though they might not be converged results, right?

can somebody give some help?

Best.

weiqiang.
Weiqiang Liu is offline   Reply With Quote

Old   February 16, 2019, 10:50
Default
  #2
Senior Member
 
Lucky
Join Date: Apr 2011
Location: Orlando, FL USA
Posts: 5,674
Rep Power: 65
LuckyTran has a spectacular aura aboutLuckyTran has a spectacular aura aboutLuckyTran has a spectacular aura about
Residuals can be unchanging even when results change because residuals are averaged over the domain.


Quote:
Originally Posted by Weiqiang Liu View Post
all the results should keep unchanged though they might not be converged results, right?

If the results are unchanged then that would be convergence...
LuckyTran is offline   Reply With Quote

Old   February 17, 2019, 12:17
Default
  #3
Senior Member
 
Weiqiang Liu
Join Date: Feb 2018
Posts: 278
Rep Power: 9
Weiqiang Liu is on a distinguished road
Quote:
Originally Posted by LuckyTran View Post
Residuals can be unchanging even when results change because residuals are averaged over the domain.





If the results are unchanged then that would be convergence...
OK I got it. Thanks very much!
Weiqiang Liu is offline   Reply With Quote

Reply

Tags
convergen, residuals


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 Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Converged variable with changing residuals query em17 OpenFOAM Running, Solving & CFD 1 July 28, 2019 09:23
Mesh Convergence Study - simpleFoam: Confusing Results Karpfen OpenFOAM 0 February 5, 2018 07:34
Changing from First to Second Order change, Fluctuating Residuals treviusss FLUENT 1 January 5, 2018 08:01
judging convergence through residuals MachZero Main CFD Forum 7 December 25, 2012 12:18
Accuracy and convergence pawan1989 FLUENT 5 April 15, 2010 17:17


All times are GMT -4. The time now is 11:56.