Basic Study on Turbulent Lubrication : 3rd Report, Consideration on the Law of Velocity Distributions and the Structure of Turbulent Flow

Abstract

In this report, the discrepancy on the Law of the wall described in the previous report has been clarified. First of all, shear stress distribution has been theoretically and experimentally investigated. The relationship between velocity and shear stress gradients is considered in order to learn about the validity of the similarity laws on the velocity distributions, using the mixing length model. Karman constant x and damping-length constant A⁺ proposed by Van Driest are obtained for a parameter a_sv/u_*³, and discussed in comparison with the moving equilibrium condition. Townsend's linear stress model is also discussed in the approximate gradient layer.