# Law of the wall

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 Revision as of 20:15, 5 September 2011 (view source)Peter (Talk | contribs)m (Changed constant in formula and table from C to B to match formula in plot)← Older edit Revision as of 07:58, 6 September 2011 (view source)GeeZ (Talk | contribs) (Changed image (now is a clear png file generated from a *.svg).)Newer edit → Line 25: Line 25: In the image y is replaced with the letter n. In the image y is replaced with the letter n. - [[Image:law of the wall.jpg]] + [[Image:Img_lawOfTheWall_whiteBG.png‎]] {{stub}} {{stub}}

## Revision as of 07:58, 6 September 2011

In the log layer the velocity profile can be estimated with the log law:

$u^+ = \frac{1}{\kappa} \, ln(y^+) + B$

and close to the wall in the viscous sublayer

$u^+ = y^+$

Where:

 $u^+$ Dimensionless velocity $y^+$ Dimensionless wall distance $\kappa$ von Karman's constant ($\approx 0.41$) $B$ Constant ($\approx 5.1$)

We should have a lin-log plot here of a typical turbulent boundary layer to illustrate where the log-law is valid, anyone have one handy?

In the image y is replaced with the letter n.