Wall-bounded vortex destruction using unsteady actuators on a flat plate

Wall-bounded vortices in flows can dominate the flow dynamics and fluid forcing in many applications. In many cases, the impact of the vortex is negative. Our aim is to test a new method for destroying pre-existing coherent vortex motion in wall-bounded flow. We generate longitudinal streamwise vortex structures using rectangular tab-style vortex generators. The coherent vortex structures are then interrupted by a synthetic jet to decay the vortex structure more rapidly. While synthetic jets with rectangular orifices are commonly used as vortex generators, we used orifice orientations that specifically generate little coherent vortex motion downstream---minimizing the impact of the jet itself. Data were collected in a low-speed wind tunnel using stereoscopic particle image velocimetry. Two heights of vortex generators were explored along with different spanwise positions along the wind tunnel floor, shifting the center of the vortex core. The synthetic jets broke up the incoming vortex core into smaller and less coherent vortex structures. However, the velocity deficit region in the wake of the vortex generator persists downstream. The pressure field in the wake of the vortex generator and synthetic jet interaction region will be explored to gauge if the unsteady forcing is mitigated.