# Convergence

 User Name Remember Me Password
 Register Blogs Members List Search Today's Posts Mark Forums Read

 LinkBack Thread Tools Display Modes
 January 22, 2008, 09:09 Convergence #1 CD Guest   Posts: n/a Hi, Wonder if anyone can give me some tips on how to get your simulation to converge? I assume the mesh quality is essential for convergence? Also how do you know if its converged? If it flatlines can you assume it has converged? Any help would be great thanks!

 January 23, 2008, 07:14 Re: Convergence #2 PHOENICS Guest   Posts: n/a Some advice is given here: http://www.cham.co.uk/phoenics/d_pol...s/converge.htm

 January 25, 2008, 13:13 Re: Convergence #3 Patti Guest   Posts: n/a I've found that convergence varies widely with the types of models you're using and the types of simulation you're trying to run. For instance, I've found that combustion models benefit from the use of the (old) SARAH setting.

 March 18, 2008, 18:15 Re: Convergence #4 EF Guest   Posts: n/a Hy, Linear relaxation should be used for Pressure and ke / ep. I found 0.4 for P1, 0.3 for KE and 0.4 for ep work nice for much cases. Velocity relaxation depends much on the cell diameter and the velocity in the smalles cell. Choose the velocity relaxation factor as a false time step equal or lower than the shortest time the flow needs to cross the cell. Example: For a cell of 100mm and a flow speed of 10m/s the relaxation factor has to be lower than 0.01 Temperature relaxation can be a factor of 10 - 50 higher than velocity relaxation. Most problems with relaxation come from small cells or a bad grid. Try without parsol and use higher tolerance to find problems. best regards, ef

 May 6, 2008, 15:45 Re: Convergence #5 PattiMichelle Sheaffer Guest   Posts: n/a Yes, this is consistent with what I've found (though I've never used parsol with chemkin) - thanks for the summary! Patti

 Thread Tools Display Modes Linear Mode

 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 OffTrackbacks are On Pingbacks are On Refbacks are On Forum Rules

 Similar Threads Thread Thread Starter Forum Replies Last Post Marie-Anne Main CFD Forum 11 September 11, 2009 10:07 vijay FLUENT 6 February 1, 2006 04:04 vijay Main CFD Forum 1 January 30, 2006 14:13 Davoche Main CFD Forum 2 November 20, 2005 06:08 LQ CFX 3 June 2, 2005 23:43

All times are GMT -4. The time now is 12:15.

 Contact Us - CFD Online - Top