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

URF for species

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

Reply
 
LinkBack Thread Tools Display Modes
Old   April 20, 2007, 03:17
Default URF for species
  #1
Claud
Guest
 
Posts: n/a
Hi Users, I am modeling steam methane reforming using 3 reactions. In order to get the whole thing started, I reduced the URF for all species down to 0.5. After getting a convered solution I started to increase the URF again in order to get better results for the interaction. Now I have almost all URF for species increased up to 0.9 exapt CO2. The URF for CO2 is still at 0.68 but already this URF results in rather high residuals. As soon as I try to increase this value i get floating point error or the residuals for all other equations increase further more. I am using second upwind order discretization. What is the reason for this behavior and how can I solve it? Thanks for the hints! Claud
  Reply With Quote

Old   April 20, 2007, 12:37
Default Re: URF for species
  #2
ravindra
Guest
 
Posts: n/a
hi

my suggestion is dont wait to increase the species urf untill convergence . i mean increase species urf before convergence to default change the species urf with other urfs

hope this helps
  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
URF and convergence in natural convergence Marie-Anne Main CFD Forum 11 September 11, 2009 10:07
urf rsi Main CFD Forum 0 February 21, 2008 23:27
Help! Where is the URF for volume fraction? gogo FLUENT 0 January 23, 2006 16:08
URF - Pressure, Velocity co2 FLUENT 0 May 11, 2004 21:36
Combustion convergence and URF Mark FLUENT 2 January 19, 2004 22:32


All times are GMT -4. The time now is 18:03.