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

solver settings, residuals plateau for a long time

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

Reply
 
LinkBack Thread Tools Display Modes
Old   December 14, 2007, 16:15
Default solver settings, residuals plateau for a long time
  #1
Mumawalde
Guest
 
Posts: n/a
Hello,

I have a question regarding solver settings in the k-e model with all of the default settings. I have a case that is primarily pipe flow. I setup my case of about 500000 nodes and allow it calculate. I am using scalable wall functions and acceptable yplus values. And, my results look great.

My question is that of time. When I start the case, it iterates for approximately 60 iterations with the residuals falling to levels of about 1.5E-04 then the residuals begin to level out. It then can take 100 more iterations to go down to the default threshold of 1E-04. The curve is monotonic and well behaved.

Does anyone know of a setting that can be used to help remove this asymptotic behavior and allow the solution to converge to accpetable levels sooner. Or, does anyone have experience with a case that behaves as explained, and know if ending the case early is an acceptable solution to saving time?

Thanks in advance for you help.
  Reply With Quote

Old   December 16, 2007, 17:47
Default Re: solver settings, residuals plateau for a long
  #2
Glenn Horrocks
Guest
 
Posts: n/a
http://www.cfd-online.com/Wiki/Ansys...gence_criteria

Glenn Horrocks
  Reply With Quote

Old   December 17, 2007, 09:49
Default Re: solver settings, residuals plateau for a long
  #3
Mumawalde
Guest
 
Posts: n/a
Thanks!
  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
Hydrostatic Pressure and Gravity miliante OpenFOAM Running, Solving & CFD 132 October 7, 2012 22:50
Settings in Solver Control Roland R CFX 1 October 12, 2011 06:44
Upgraded from Karmic Koala 9.10 to Lucid Lynx10.04.3 bookie56 OpenFOAM Installation 8 August 13, 2011 04:03
Computational time sunnysun OpenFOAM Running, Solving & CFD 5 March 16, 2009 04:32
Differences between serial and parallel runs carsten OpenFOAM Bugs 11 September 12, 2008 11:16


All times are GMT -4. The time now is 20:27.