Effect of a Jet Vortex Generator on a Turbulent Boundary Layer: 2. Analysis of Unsteady Characteristics

Abstract

This study investigates the unsteady flow characteristics arising from the interaction between a streamwise vortex, induced by wall jet injection, and a turbulent boundary layer. Velocity field measurements are measured using Particle Image Velocimetry. The data analysis was quantify the following: turbulence anisotropy, characteristic length scales of turbulent structures, and identify dominant coherent structures using Proper Orthogonal Decomposition (POD). The results reveal mutual interaction between the turbulent boundary layer and the streamwise vortex, which depends on the vortex intensity. It is shown that the air jet vortex generator significantly alters both the mean flow topology and the unsteady dynamics of the turbulent boundary layer.