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

diffusion effect opposite to convection

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   December 5, 2006, 07:59
Default diffusion effect opposite to convection
  #1
hasan karabay
Guest
 
Posts: n/a
Hi In a uniform flow field, I would like to see the diffusion effect opposite to convection.

To do so

I draw a square 1x1 with uniform 2d mesh I setup the left side as a velocity inlet with U velocity component =1 m/s V velocity component =10.5 m/s Constant temperature =300 K

Bottom Side velocity inlet with U velocity component =1 m/s V velocity component =10.5 m/s Constant temperature =300 K

Top Side velocity inlet with U velocity component =1 m/s V velocity component =10.5 m/s Constant temperature =2000 K

Right side Pressure outlet

Also I increased the heat conduction coefficient of the fluid to be able to see the diffusion effects (k/(rho*Cp)>>1 ). I just wanted to see temperature gradients opposite to flow direction.

I run the case. I have got the uniform velocity field but what ever I did I could not get any temperature gradient opposite flow direction. I have reduced velocities, increased the k and the temperature at the top. The temperature profile at the top swept out by convection.

However when I increased the temperature at the left side, I can get a temperature gradient perpendicular to flow direction.

Am I doing something wrong or these codes ignore the diffusion effect opposite the flow direction.

thanks

  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
Convection, diffusion and reaction Joao CFX 0 October 25, 2008 21:19
No Convection/Diffusion: CFX4 Robin K CFX 0 September 28, 2005 17:52
transient diffusion convection Volker Göke CFX 1 June 26, 2003 17:20
convection dominated convection-diffusion problem Kang, S. K. Main CFD Forum 0 December 22, 2000 15:25
Diffusion / convection I. Dotsikas Main CFD Forum 2 April 21, 1999 17:39


All times are GMT -4. The time now is 23:27.