ON THE APPLICATION OF THE UNIVERSAL LAW
OF VELOCITY DEFECT TO NONEQUILIBRIUM FLOWS
IN A TURBULENT BOUNDARY LAYER

Yu. A. Lashkov*, V. V. Mikhailov,
N. V. Samoilova, and A. A. Uspenskii

UDC 532.542.4

On the basis of the results of measurements of the mean 
velocity profile of a 2-D turbulent boundary layer of an incompressible 
liquid, the previously proposed universal law of velocity defect has 
been refined. It has been shown that the refined relations are also 
applicable to nonequilibrium flows in the boundary layer. The proposed 
method makes it possible to determine the friction coefficient by 
the known values of the form parameter and the Reynolds number calculated 
by the displacement thickness of the layer in a wider range of these 
values compared to the known Ludwieg-Tillman formula.

*Deceased

Prof. N. E. Zhukovskii Central Aerohydrodynamic Institute, 
Zhukovskii, 140180, Moscow Region, Russia; email: n.samoilova@mail.ru. 
Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 81, No. 5, pp. 
834-843, September-October, 2008. Original article submitted 
April 18, 2007; revision submitted August 30, 2007.