Distribution of mean velocity in turbulent boundary layer over permeable surface with air blowing
V.I. Kornilov
Khristianovich Institute of Theoretical and Applied Mechanics SB RAS
kornilov@itam.nsc.ru
Keywords: incompressible turbulent boundary layer, permeable wall, microblowing, velocity profile
Pages: 9-16
Abstract
In the present article, we investigate the possibility of using simple physical models for predicting properties of incompressible turbulent boundary layer on permeable wall at various values of air-microblowing mass flow rate. It is shown that the velocity scaling U∞δ*/δ99 can be successfully used to approximate the distribution of mean velocity in the outer region of the boundary layer. The use of this scaling makes the velocity profiles invariant with respect to Reynolds-number variation; this circumstance largely facilitates the analysis of experimental data, making it independent of upstream flow conditions. The distribution of mean velocity in the logarithmic flow region of the boundary layer over permeable surface can be described with a modified law of the wall involving a constant C0 equal to the same constant for canonical boundary layer, and a quantity K being a weak function of blowing ratio.
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