Experimental Study of Synthetic Jets with Cross Flow in Boundary Layer

Abstract

The synthetic jet actuator is a low power, highly compact fluidic device which has potential application in boundary layer flow control. In this study, we have shown how synthetic jets work without cross flow and how effectively they modify the flow structure in the boundary layer. This paper describes the electrodynamics synthetic jet actuator used in our experiments. The experimental set-up for flow control using this type of actuator is detailed. The flowfield resulting from the interaction of a synthetic jet actuator and a quiescent environment and of synthetic jet actuator and a turbulent, flat-plate, zero pressure gradient boundary layer were examined via Particle Image Velocimetry (PIV) . The synthetic jet actuator was tested and two forcing amplitudes were investigated. Inspection of the phase-averaged velocity revealed that spanwise large-scale vortices are generated downstream of the slot and were persisting farther downstream.