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

wall boundary condition

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

Reply
 
LinkBack Thread Tools Display Modes
Old   August 7, 2010, 03:37
Default wall boundary condition
  #1
New Member
 
Safa van Jansen
Join Date: Aug 2010
Posts: 2
Rep Power: 0
safa_c is on a distinguished road
My question is about the wall boundary condition in cell-centered finite volume solver.

I assume when fixed and uniform wall boundary condition is applied to a surface of a 3D geometry before my CFD simulation, it should remain uniform and unchanged during the simulation.

When I check the contours of temperature of wall boundary condition after the simulation is converged, I can see that the solver (FLUENT) gives me a non-uniform temperature over the surface. (I checked it with and without node value)

Can anybody give me a hint why it happens?
safa_c is offline   Reply With Quote

Old   August 9, 2010, 12:55
Default
  #2
New Member
 
Akinola
Join Date: Jul 2010
Posts: 25
Rep Power: 7
falopsy is on a distinguished road
In cell-centred finite volume method, the boundary conditions are implemented directly in the equations and the no values is stored for the variables at the boundaries (wall, symmetry etc). During post-processing, the values at the boundaries are actually extrapolated from the values close to the boundaries, so you end up not getting exactly the values implemented in the equations as the values now depends on the type of interpolation. The values will be very close though.

I'll advice you check the values and see if the differences is not too great. Check the range of your temperature contour and see if the discrepancies is not too great. If you have too high discrepancies, then maybe your solution is not yet converged enough (grid independence and lower residuals) and check everything is implemented well.

I hope this helps.
falopsy is offline   Reply With Quote

Reply

Tags
wall boundary conditions

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
How to set rotating wall as boundary condition babu FLUENT 7 December 14, 2013 05:48
Change wall boundary condition in multiphase? Jacques FLUENT 0 November 27, 2008 07:26
Variable temperature wall boundary condition Virginie FLUENT 2 October 2, 2007 09:23
the boundary condition of permeable wall lisa FLUENT 12 May 5, 2005 20:58
isothermal wall boundary condition Neil Main CFD Forum 2 December 18, 2004 13:15


All times are GMT -4. The time now is 23:48.