S053071 Effect of Cylinder Wake in a Freestream on Characteristics of Turbulent Boundary Layer and Bursting Event

Abstract

Effects of the cylinder wake in a freestream on statistical properties of a turbulent boundary layer over a flat plate are experimentally investigated in a wind tunnel. The cylinder is set horizontally over the flat plate. We investigated 3 types of interactions between the wake and the zero-pressure-gradient turbulent boundary layer. Instantaneous velocity is measured by using the hot wire anemometry. We used the variable interval time average (VITA) technique to detect the bursting event. The results show that the time-averaged mean velocity in the inner layer for the case with the cylinder wake coincides with that for the case without the cylinder wake. However, turbulence intensities and Reynolds stress normalized by the inner parameters are suppressed in the outer layer by the cylinder wake. It is found that the velocity fluctuation during the sweep phase in the bursting event is increased by the cylinder wake.