# Friction velocity

(Difference between revisions)
 Revision as of 14:54, 11 May 2006 (view source)Jola (Talk | contribs)m← Older edit Revision as of 13:20, 13 May 2006 (view source)Jola (Talk | contribs) Newer edit → Line 3: Line 3: :$u_* \equiv \sqrt{\frac{\tau_w}{\rho}}$ :$u_* \equiv \sqrt{\frac{\tau_w}{\rho}}$ - Where $\tau_w$ is the wall shear stress and $\rho$ is the fluid density at the wall. + Where $\tau_w$ is the [[Wall shear stress|wall shear stress]] and $\rho$ is the fluid density at the wall.

## Revision as of 13:20, 13 May 2006

Dimensional analysis shows that at a wall a charateristic velocity, called the friction velocity, $u_*$, can be defined in the following way:

$u_* \equiv \sqrt{\frac{\tau_w}{\rho}}$

Where $\tau_w$ is the wall shear stress and $\rho$ is the fluid density at the wall.