Experimental investigation of wingtip vortices control with synthetic jets

Wingtip vortices are proven to be detrimental to both aircraft efficiency and safety due to their adverse effects such as wake hazard, blade vortex interaction (BVI) noise, and induced drag. The present research focuses on the experimental investigation of the effectiveness of synthetic jet actuation control on the wingtip vortices and their development. In order to preserve the mutual induction of the counter-rotating vortices during their evolution, an unswept, low aspect ratio, squared-tipped, finite-span wing is employed. The synthetic jet actuation is based on triggering the inherent instabilities of Crow and Widnall at different momentum coefficient to reduce the vortices strength, the induced circumferential velocity, and to obtain an anticipated vortices break up. Different exit geometries of the synthetic jet have been tested to analyze the effects of the jet velocity and jet position changes on the wingtip vortices. A proper phase-locked stereoscopic particle image velocimetry setups have been designed to carry out such a parametric study in the near and far wake of the wing. Due to the actuation at low frequency, the vortices instability is prematurely risen up and amplified, leading to an early vortices linking and their consequent dissipation.