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

Re Radiation

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

Reply
 
LinkBack Thread Tools Display Modes
Old   February 23, 2000, 18:04
Default Re Radiation
  #1
Guosheng Kang
Guest
 
Posts: n/a
Hello, I am solving a combustion problem, in which P-1 model is used for radiation. The combustion system is methane-air, but in my problem, some oxygen is added to the air, which is the so called "Oxygen Enriched Air". I copied the methane-air data just from the database, however, the default Absorption Coefficient is zero(1/m) and the Scattering Coefficient is zero (1/m), too. These two coefficients should be non-zeros when P-1 model is used, I hope some experts are there to give me a clue. Thank you for response.

Guosheng
  Reply With Quote

Old   February 24, 2000, 02:35
Default Re: Re Radiation
  #2
Jouni Valtatie
Guest
 
Posts: n/a
Hi!

There should be in the drop down list beside the absorption coefficient options: WSGGM-domain-based and WSGGM-cell-based (Weighted Sum of Grey Gases Model). Choose one of these and your model will compute composition dependent absorption coefficient. Check your manual for details. Basically you should choose domain-based if you are more interested in overall heat transfer into domain boundaries, cell based if you are more interested in the inner behaviour of the flame.

I think that in gas combustion it is safe to leave the scattering coefficient to zero, because there shouldn't be particles, which produce scattering, but check your manual for details.

Best Regards,

Jouni
  Reply With Quote

Old   February 27, 2000, 23:52
Default Re: Re Radiation
  #3
Guosheng Kang
Guest
 
Posts: n/a
Thanks Jouni, I tried as you suggested, it works better now. Talk to you later, seems another issue is of concern.

Guosheng
  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
natural convection problem with radiation jorien CFX 0 October 14, 2011 09:26
Surface incident radiation Pipiola FLUENT 0 August 11, 2009 15:46
Multiphase radiation in CFX Luk_Fiz CFX 5 March 17, 2009 04:51
Radiation: definitions visatron CFX 7 January 8, 2004 16:25
Fluent incident radiation problem Michael Schwarz Main CFD Forum 0 October 21, 1999 05:56


All times are GMT -4. The time now is 13:54.