CFD Online Logo CFD Online URL
Home > Forums > FLUENT

Natural convection of in gas-gas system

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

LinkBack Thread Tools Display Modes
Old   January 5, 2003, 21:08
Default Natural convection of in gas-gas system
yee wan
Posts: n/a
Hi people there! Do anyone tried to simulate the natural convection phenomena in gas-gas system (by diffusion) using FLUENT??

I am wondering wether FLUENT can do this or not??

If anyone has been done it sucessfully, pls share with me how do u setup the things.. By now i am using the species transport model...

Thanks in advance...


  Reply With Quote

Old   January 13, 2003, 19:17
Default Re: Natural convection of in gas-gas system
Greg Perkins
Posts: n/a
I had a look at this a bit - but was mainly concerned with convection due to temperature gradients rather than concentration gradients. I found no major problems - just tern on the species model, activate gravity, and either use a steady or transient solver depending on the flow regime (Ra number).

When you say natural convection by diffusion I assume you mean driven by changes in the density caused by concentration gradients.

  Reply With Quote

Old   January 22, 2003, 04:34
Default Re: Natural convection of in gas-gas system
yee wan
Posts: n/a
Thanks alot Greg, Yes now I am using the species transport for the convection case.

But then do you know how to determine the surface concentration of a defined boundary??

What i do is go to -->report-->surface intergal--> average: molar concentraction... to the the concentraction of the species at the mass flow inlet boundary..

But the value given but FLUENT is much more smaller than the theoritical value I caculated...Do you/anyone know that what actually this concentarction mean?? what volume do the FLUENT refer to in this case?? for me it seem that FLUENT use the total domain volume to calculate the molar concentraction...can anyone give me a solution??

Thankas alot

  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
Constant velocity of the material Sas CFX 15 July 13, 2010 08:56
Natural Convection with heat generation krishnachandranr Main CFD Forum 0 July 28, 2009 04:22
Natural gas combustion Newbie Main CFD Forum 7 May 22, 2004 04:00
Gas pressure question Dan Moskal Main CFD Forum 0 October 24, 2002 22:02
natural convection in a sealed enclosure James Main CFD Forum 4 April 2, 2001 15:48

All times are GMT -4. The time now is 10:11.