Leading-Edge Vortex Dynamics on Plunging 2D and 3D Wings

The dynamics of the three-dimensional leading-edge vortices on plunging wings and airfoils is examined by means of phase-locked volumetric velocity measurements in a water tunnel. Two configurations are tested in present investigation: a finite wing with a tip (3D) and an infinite wing without tip effects (2D). Interactions with secondary vortices and trailing-edge vortices as well as the attached leg near the wing-tip contribute to the observed spanwise instabilities. In order to introduce spanwise instabilities and excite the leading-edge vortex filament, various control methods are tested. These include vortex generators, spoilers, and wing-tip geometry modification. The results show that these methods might be effective for controlling the leading-edge vortex structure and accelerating the three-dimensionality of the vortex filaments on plunging wings.