friction velocity

friction velocity

[′frik·shən və′läs·əd·ē]
(meteorology)
A reference wind velocity defined by the relation u =√(|τ/ρ|,) where τ is the Reynolds stress, ρ the density, and u the friction velocity.
References in periodicals archive ?
These two parameters of the wind wave spectrum were related, in dimensionless forms, to the fetch X and the friction velocity of the wind [U.
From this background, we have developed a LES of a fully-developed turbulent flow laden with solid particles in a vertical channel and additionally, we have extended the study to a vertical pipe with the same Karman number (or Reynolds number based in friction velocity, Ret).
s]), cm Hydraulic Froude number (Fr), Ratio of inertial to gravitational dimensionless forces in flow Boundary Reynolds number Ratio of internal to external (Re*), dimensionless turbulent forces Shear velocity (U*), cm/s Friction velocity Shear stress ([tau]), Force of friction on substrate dynes/[cm.
3 m; 1500 m; 20 m/s), where the friction velocity is [u.
According to Clauser (1954), turbulent boundary layers where the plots of velocity defect normalised with the local wall friction velocity ([U.
is the friction velocity, K is the von Karman constant ([approximately equal to]0,41), g is the acceleration due to gravity, [z.
3] Pa when [alpha] = 30[degrees] x 2) The friction velocity [u.
f] are the friction velocity, acceleration of gravity, flow depth, and energy gradient, respectively.
TKE and friction velocity (U*) are very well correlated and detect the turbulent periods of the nights, and the stable ones too.
Hagen (1996) stated that the friction velocity at the soil surface drives the erosion process.