Vortex topology of wing tip blowing

Abstract

An extensive parametric study was conducted to examine the effect of continuous blowing from high aspect ratio jets on the tip vortex in the near wake. It was found that the high aspect ratio jet produces a pair of counter-rotating vortices of unequal strength; their interaction with the tip vortex leads to single or multiple-vortex wakes. The flow topology of the wake depends on a number of parameters such as the blowing configuration, the blowing coefficient and the wing incidence. Vertical and spanwise blowing were examined, from different vertical and longitudinal positions. In most cases, blowing from near the pressure surface led to diffused vortices in the near wake with blowing from near the suction surface producing the opposite effect. The tip shape was also varied; the round tip showed the ability to promote the Coanda effect, thus modifying the vortex interaction. The wing incidence was found to affect not only the tip vortex but also the jet-generated vortices.