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

radiation in CFX

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

Like Tree4Likes

Reply
 
LinkBack Thread Tools Display Modes
Old   May 17, 2013, 07:20
Default Radiation
  #21
New Member
 
Abdalla
Join Date: May 2013
Posts: 4
Rep Power: 4
aleghfeli is on a distinguished road
Dear topsedar, I am simulating the same case and i don't know how to design the vacuum between two solids where only heat radiation occurs. Did you assume it is as solid and what are the material properties? or is there another way to setup the vacuum? I really appreciate your help. Thank you.
aleghfeli is offline   Reply With Quote

Old   May 17, 2013, 07:30
Default
  #22
Super Moderator
 
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 10,951
Rep Power: 85
ghorrocks has a spectacular aura aboutghorrocks has a spectacular aura aboutghorrocks has a spectacular aura about
My posts tell you exactly how to do it. Model it as a transparent solid with an almost zero thermal conductivity.
ghorrocks is offline   Reply With Quote

Old   May 17, 2013, 07:49
Default
  #23
New Member
 
Abdalla
Join Date: May 2013
Posts: 4
Rep Power: 4
aleghfeli is on a distinguished road
Dear ghorrocks, how can i make the solid transparent and what are the suggested values of the solid material properties as shown in the attachment. I appreciate your help and thank you
Attached Images
File Type: jpg CFD.jpg (93.6 KB, 8 views)
aleghfeli is offline   Reply With Quote

Old   May 17, 2013, 09:20
Default
  #24
Super Moderator
 
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 10,951
Rep Power: 85
ghorrocks has a spectacular aura aboutghorrocks has a spectacular aura aboutghorrocks has a spectacular aura about
The tab you are showing is for a fluid. You need to make it a solid.

In the radiation properties make absorption coeff=0. Now it does not absorb, that is it is transparent.
ghorrocks is offline   Reply With Quote

Old   May 17, 2013, 09:38
Default
  #25
New Member
 
Abdalla
Join Date: May 2013
Posts: 4
Rep Power: 4
aleghfeli is on a distinguished road
This photo is for the material properties which its thermodynamic state is chosen to be solid. It solid domain will be chosen when applying boundary condition as shown in the attached photo "CFD2.jpg". If I am still doing it wrong please tell me what is the correct way. Otherwise will you please give me the best properties approximation that represents the vacuum material as shown in the first attached "CFD.jpg". In term of "Molar mass, Density, Specific heay capacity, Ref. Spec. Enthalpy, Entropy, Dynamic Viscosity, Thermal Conductivity, Refractive Index, Absorption Coefficient, Scattering Coefficient, Thermal Expansivity"
Attached Images
File Type: jpg CFD.jpg (93.6 KB, 3 views)
File Type: jpg CFD2.jpg (56.8 KB, 3 views)
aleghfeli is offline   Reply With Quote

Old   May 17, 2013, 14:10
Default
  #26
New Member
 
Abdalla
Join Date: May 2013
Posts: 4
Rep Power: 4
aleghfeli is on a distinguished road
Will you please look into my question? The submission is soon and I need to be done with it. Thank you
aleghfeli is offline   Reply With Quote

Old   May 17, 2013, 19:12
Default
  #27
Super Moderator
 
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 10,951
Rep Power: 85
ghorrocks has a spectacular aura aboutghorrocks has a spectacular aura aboutghorrocks has a spectacular aura about
Almost all of those parameters are irrelevant. Some require values just to keep the solver happy. I will leave it as an exercise for you to work this out. If you are not sure whether a parameter is important or not then do a sensitivity check (run a value then 10x the value and see if it makes a difference) to find out.

And just a comment - do not rush people on a free open forum like this. If you are in a hurry you should pay for support from ANSYS. On a free forum you get help when we get around to it.
ghorrocks is offline   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
Multiphase radiation in CFX Luk_Fiz CFX 5 March 17, 2009 04:51
Importing solutions in CFX. Alphonso CFX 1 August 1, 2008 14:01
Questions about radiation modelling Yingchun CFX 5 November 23, 2005 02:53
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 11:12.