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

Residual value

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   March 3, 2003, 05:33
Default Residual value
  #1
Mark
Guest
 
Posts: n/a
Hi all~

I have a convergence problem. My model is 1/8 model of axial fan. Cell numbers are 620000. During iteration, the residual values are not decreasing. They are oscillated or very slowly decraasing. What's wrong with my problem or What I need to do?
  Reply With Quote

Old   March 3, 2003, 11:15
Default Re: Residual value
  #2
cjtune
Guest
 
Posts: n/a
I think it's the consequence of using the less accurate implicit MRF over the explicit MRF method. You are using the implicit method, right?

I did this last time: start from a low RPM, then stop. Restart with a higher RPM, stop after awhile, and then restart with a even higher RPM and so on, until you reach the RPM you want. It didn't really converge at my ultimate RPM but at least the residuals are a magnitude lower than they were (ie. 'good enough' for me...). I think you can you the advanced transient module's load steps instead of stopping and restarting so many times.

  Reply With Quote

Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
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 Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
PHI residual (using the old or new value ?) Noel Phoenics 1 March 3, 2009 06:22
No KE residual kasim CFX 0 March 12, 2008 16:43
Residual? Beginner Main CFD Forum 1 June 1, 2007 00:59
RMS Residual Nikos CFX 1 August 25, 2006 10:14
Residual Beni Main CFD Forum 0 September 24, 2005 17:48


All times are GMT -4. The time now is 07:18.