CFD Online Logo CFD Online URL
Home > Forums > Siemens

baffle in use

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

LinkBack Thread Tools Display Modes
Old   November 7, 2003, 01:24
Default baffle in use
guang ai
Posts: n/a
I have a problem with using baffle. I run a problem with a baffle put in nearly half of the path. It was keeping diverged in less than 200 iteration no matter what a relaxation I selected, such as R for press < 0.05. Once I switch the fluid adjecent to baffle to solid, calculation converged to -3 order of magnitude in mass. Does anyone have similar problem before or any suggestion, I will feel very grateful.
  Reply With Quote

Old   November 7, 2003, 14:27
Default Re: baffle in use
Posts: n/a
Is your flow domain completely separated by the baffles? That would imply that they are permeable baffles. In that case: Start with a low pressure loss over the baffles and restart with higher ones, until you reach your desired value.
Hope that helps, Marc
  Reply With Quote

Old   November 9, 2003, 20:14
Default Re: baffle in use
guang ai
Posts: n/a
thank you for your response. my case is not that complicated as you guessed, with only mesh seems complex. it is a problem with flow bifurcated for a distance and merged again at downstream. once a baffle works as a door shut off one side path, diverge happens. mesh quality is not good but works well as i mentioned in first post.
  Reply With Quote

Old   November 10, 2003, 05:51
Default Re: baffle in use
Posts: n/a
If your baffle door shuts off a side path, and the fluid in that path becomes completely separated from the rest of the flow, it becomes a two-stream problem. In other words, you have two completely separate flow domains. This is numerically unstable, and requires some special treatment.

See Tutorial 13 for how to handle that - Tut 13 is a moving mesh case, but you should get the idea.
  Reply With Quote


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
baffle and wall BC in v4.06 solarwind Siemens 0 January 16, 2009 04:43
HELP: baffle generation sunlight Siemens 3 July 29, 2005 03:07
baffle boundary sankar Siemens 3 March 16, 2005 04:54
Baffle problem.. mohr76 Siemens 0 July 14, 2004 07:37
porosity of baffle raymond Siemens 4 April 4, 2002 04:03

All times are GMT -4. The time now is 03:26.