A model of average velocity in oscillating turbulent boundary layers

Abstract

A model to calculate the vertical distribution of the average velocity in the oscillating turbulent boundary layer forced by the overlaying oscillating free flow is discussed. The model is founded on the Rotationally Anisotropic Turbulence theory. The oscillating boundary layer is treated within the approximation of average velocity depending on the time and vertical coordinate only. The description results in an analytical expression for the flow velocity analogous to the expression for the flow velocity in the boundary layer of oscillating pipe flow. The resulting expressions for the vertical velocity profile are compared with respective laboratory data obtained in two tests of an oscillatory water tunnel experiment. It is shown that similar to the description of oscillating flow in tubes, the outcome of the suggested model with the appropriate values of the model parameters matches the measured velocity data reasonably well.

Keywords:

• Analytical solution
• Mathematical modeling
• Oscillatory boundary layer
• Rotational viscosity
• Turbulence