Effect of Pitch Angle of Vortex Generator Jets on Flowfield near Wall

Abstract

The vortex generator jets (VGJs) method can control flowfields or especially suppress flow separations in a wide range of conditions. The experiments were conducted using a low speed wind tunnel with a two-dimensional diffuser. To obtain a better understanding of the control we investigated the flowfield near the wall where the separation might occur. We measured the secondary flow and vorticity distribution at the downstream of the diffuser. We find that secondary flow toward the lower wall is not necessary for suppressing separation at target position if there exists a secondary flow of enough strength at the upstream of the position.