tau]] is the friction velocity
[m/s] defined as below,
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
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
According to Clauser (1954), turbulent boundary layers where the plots of velocity defect normalised with the local wall friction velocity
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
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.
is the ratio of local velocity to the friction velocity
Hagen (1996) stated that the friction velocity
at the soil surface drives the erosion process.