CFD Online Logo CFD Online URL
Home > Forums > FLUENT

Implementation of wall functions with a constant shear boundary condition

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

LinkBack Thread Tools Display Modes
Old   February 27, 2012, 08:49
Arrow Implementation of wall functions with a constant shear boundary condition
New Member
Join Date: Aug 2010
Location: Southampton
Posts: 12
Rep Power: 9
General_Gee is on a distinguished road

I am trying to understand the implementation of wall functions in FLUENT when I specify a constant shear BC.

If I just set it to be a wall I understand what happens is:
1. Take cell centre velocity and calculate u_tau from the log-law relationship.
2. Calculate tau_w and apply this as a BC at the wall.
3. Solve the N-S Eqns in the cell to calculate the new cell centre value.

But what happens when I specify the wall shear stress. How does the log-law relationship get used in the calculation. Because all I can see is that you skip step one above, and just do two-three.

I understand there are lots of different details that I have ignored eg u_star vs u_plus and the exact log-law relationship etc, but I just want to get my head around the application.

Any input is much appreciated.
General_Gee is offline   Reply With Quote


fluent, shear stress, wall function, wall shear

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
Domain Imbalance HMR CFX 5 October 10, 2016 05:57
UDF setting wall boundary condition with a DEFINE_PROFILE NLao FLUENT 1 April 17, 2011 05:23
mass flow in is not equal to mass flow out saii CFX 2 September 18, 2009 08:07
New topic on same subject - Flow around race car Tudor Miron CFX 15 April 2, 2004 06:18
what the result is negatif pressure at inlet chong chee nan FLUENT 0 December 29, 2001 06:13

All times are GMT -4. The time now is 12:04.