CFD Online Logo CFD Online URL
Home > Forums > OpenFOAM Running, Solving & CFD

Friction Velocity

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

LinkBack Thread Tools Display Modes
Old   March 5, 2010, 03:15
Question Friction Velocity
New Member
Join Date: Nov 2009
Location: Durban, South Africa
Posts: 9
Rep Power: 9
Pooven is on a distinguished road
Hi there,

I don't have a CFD background so I'm not sure if what I've done is correct; I was hoping for some clarity... I want to define a drag force at the floor of my simulation. I do this in the /0/U file:
In the boundaryField sub-dictionary, in the floor wall sub-dictionary I calculate the drag force using by using u_* = k u_k/ln(h/z_0).
I think that the drag force in this case is the friction velocity?

I have to represent the friction velocity as a vector so I convert it using sin(x) * u_* and cos(x) * u_* where x is in the opposite direction of the flow (though I don't think it makes a difference?) and the z component of the vector is set to 0.

Am I totally off?

Kind regards
Pooven is offline   Reply With Quote


drag force, friction velocity

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
Velocity in Porous medium : HELP! HELP! HELP! Kali Sanjay Phoenics 0 November 6, 2006 07:10
Variables Definition in CFX Solver 5.6 R P CFX 2 October 26, 2004 02:13
Simple question for friction velocity jay Main CFD Forum 0 February 12, 2004 17:12
friction velocity kei-tee Main CFD Forum 10 May 25, 2003 19:31
Terrible Mistake In Fluid Dynamics History Abhi Main CFD Forum 12 July 8, 2002 09:11

All times are GMT -4. The time now is 00:54.