CFD Online Logo CFD Online URL
Home > Forums > CFX

Radiation CFX 5.5

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

LinkBack Thread Tools Display Modes
Old   March 18, 2003, 08:17
Default Radiation CFX 5.5
Posts: n/a

I am working on oven for backing bread. I use P1 radiation method.

I would like to look only surface-to-surface radiation without air radiation. Is this posible with CFX5.5?

What should I take for absorbtion,scattering and reflection coefficient for air.

Could somebody tell me how CFX calculate radiative emission, incident radiation and radiation intensity? Equations pleace.

  Reply With Quote

Old   March 18, 2003, 13:56
Default Re: Radiation CFX 5.5
Jeff Moder
Posts: n/a
I am not a CFX user, but if you only want to do surface-to-surface radiation, i would recommend not using the P1 method if you want reasonable accuracy; you can probably get qualitative results for transparent media with P1, but heat flux errors could easily approach 30% or more. The P1 approximation is better suited to participating media with large absorption.

If CFX has a discrete ordinates or discrete transfer method, i would recommend using these, even if you only use a very small number of directions.
  Reply With Quote

Old   March 18, 2003, 19:34
Default Re: Radiation CFX 5.5
Posts: n/a
I agree with Jeff's comments.

The P1 radiation model is not good for surface-to-surface radiation, but produces reasonably good results when the optical thickness >1 (we've used it with reasonable success for gas combustion problems).

For optically thin media, discrete transfer/ray trace based models are much better. These will be available in CFX-5.6 (available April ?)


  Reply With Quote

Old   March 21, 2003, 02:44
Default Re: Radiation CFX 5.5
Posts: n/a
Could someone give me useful value for absorbtion,scattering and reflection coefficient for air.
  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
radiation between solids in CFX groonm Main CFD Forum 0 September 15, 2011 17:28
CFX 5.5 volume meshing error Bogesz CFX 0 May 12, 2002 13:19
CFX 5.5 post processor N Menon CFX 1 April 17, 2002 18:02
CFX 4.4 installation problem Pandu Sattvika CFX 1 December 1, 2001 05:07
Fluent incident radiation problem Michael Schwarz Main CFD Forum 0 October 21, 1999 05:56

All times are GMT -4. The time now is 09:27.