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

models of radiation

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   January 18, 2001, 16:43
Default models of radiation
  #1
dani
Guest
 
Posts: n/a
that radiation model which has fluent determines the radiation between surfaces considering the form factor? apparently single gas radiation is had and the radiation for surfaces is not considered

thanks

  Reply With Quote

Old   January 18, 2001, 19:27
Default Re: models of radiation
  #2
Raza Mirza
Guest
 
Posts: n/a
Dani,

I think Fluent does not have surface-to-surface radiation model (that's how I have heard people refer to it) which makes use of form factors. I think fluent offers Discrete Transfer Radiation Model (DTRM) and Discrete Ordinate Method (DOM). I am not familiar with the former, but the later is a volumetric radition model which solves for radiation engery transfer though the volume cells, tracking engery in a fixed number of ordinate directions. I believe it does not need form factor, but will account for raditation off of the bounding surfaces.

May I ask what are you trying to model?
  Reply With Quote

Old   January 19, 2001, 08:28
Default Re: models of radiation
  #3
dani
Guest
 
Posts: n/a
I am working in the model of the heat transference in a room, which has a window, a frame and a card that the effect of a curtain simulates and that this to a distance of X mm of the frame, soon I need to apply radiation to the model since between the window and the curtain the main means of heat transference are by radiation, and the curtain is like a radiativa screen, by this I need to know the radiation the curtain with the walls that surround it, and with the window, the model P1 de Fluent is the unico that allows me to place the respective emisividades of each surface, by this in the correct thing and it is possible to be occupied... you can help me with some idea?
  Reply With Quote

Old   January 25, 2001, 20:33
Default Re: models of radiation
  #4
Raza Mirza
Guest
 
Posts: n/a
Hi,

I hope by now you have already solved your problem. But in case you still need help, let me say a few things.

1. In automotive applications, a problem similar to yours often arrives when looking at the heat transfer in the underbody. There a radiation shield is placed between the hot exhaust pipe and the surrounding parts that need to be shielded from the heat. The mechanism of heat transfer is largely radiation, although in this case convection effect is also present.

2. This radtiation shield is typically modeled as a baffle (zero thickness for flow, but assigned a thickness for condution). I guess you are also trying to model it as a baffle.

3. Although I have not used it myself, one of the fluent's engineer suggested using discrete ordinate method for the automotive underbody case. I have also seen an example of such an application at Fluent's 2000 Automotive User Group meeting in Novi, Michigan.

  Reply With Quote

Reply


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
Q on some abbreviations (radiation models) ABo CFX 0 May 25, 2004 04:17
Qs on radiation models Bo CFX 0 December 17, 2003 05:45
models of radiation dory FLUENT 0 December 26, 2000 12:00
HELP!!!! RADIATION MODELS IN NATURAL CONVECTION dory FLUENT 0 December 5, 2000 13:38
HELP!!! RADIATION MODELS IN NATURAL CONVECTION dory FLUENT 0 November 29, 2000 11:51


All times are GMT -4. The time now is 23:46.