EXPERIMENTAL STUDY ON SELF-DISSIPATION-WAKE WING BASED ON INTERACTIVE INSTABILITY

Aircraft wake vortex is an inherent co-existing phenomenon connecting to the lift-generating mechanism. It exhibits in the form of tri-dimensional vortex generated by limited wings at the wing tip, which would introduce great hazard to following flight and threaten to the flight safety. Based on a simplified rectangular airfoil, two rectangle-plate flaps were attached onto the airfoil to construct a counter rotating four-vortex wake system to induce the Rayleigh-Ludwig instability of the wake, resulting in a premature breakdown of the wake vortex. The research was performed in Fluid Mechanics Lab in Xiamen University, which equipped with a towing tank and a Particle Image Velocimetry system. Under different experimental conditions, in terms of towing speed and attack angle, the wake vortex development of the test model, both with and without flaps, as well as the circulation analysis, were acquired. The study demonstrated that the decrease in circulation was 35% to 45% in 45 wingspans when flaps were introduced, whereas the counterpart of the baseline airfoil, without flaps, was only 0% to 10%, which revealed the application possibility of Rayleigh-Ludwig instability in alleviating the wake vortex.