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

Low flow rate in channel results in divergence

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

Like Tree1Likes
  • 1 Post By Purushothama

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   March 16, 2011, 23:23
Default Low flow rate in channel results in divergence
  #1
New Member
 
Purushothama Chippar
Join Date: May 2010
Posts: 15
Rep Power: 15
Purushothama is on a distinguished road
Dear friends,

I am working on DMFC simulation. I have developed a three dimensional two phase model and UDFs. Recently I tried to simulate 3*3 cm2 cell with single pass serpentine channel geometry, with 2.5/3.0 anode /cathode stoichiometry at 400 mA/cm2 operating current density. I used 0.3 and 0.5 under relaxation factors for pressure and momentum, respectively. Initially simulation goes well with decreasing residuals but after several hundreds of iterations momentum residual starts increasing and when it reaches around 1000 iteration momentum (mainly cathode side) residual increases to 10-4 and suddenly stops. For the same settings if I increase the flow rate by using large stoichiometry ratio such as 10.0/10.0 calculation converges well. I have problem only in the cathode side. Could anyone tell me the reason for divergence at low flow rate? I used pressure outlet condition at both cathode and anode. Thanks in advance.
ramakant likes this.
Purushothama is offline   Reply With Quote

Reply

Tags
fuel cell, low flow rate

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
Complex problem: Open Channel Flow lett FLUENT 18 November 10, 2018 19:30
mulltiple channel flow I.Dotsikas Main CFD Forum 2 September 23, 2010 21:49
open channel flow sachin jadhav FLUENT 0 April 9, 2008 16:53
pressure outlet (open channel flow) Willem Brantegem Main CFD Forum 0 April 3, 2007 10:39
compressible channel flow.. R.D.Prabhu Main CFD Forum 0 July 17, 1998 18:23


All times are GMT -4. The time now is 07:10.