Effects of Synthetic Jet Actuation on a Ramping NACA 0015 Airfoil

An experimental investigation was undertaken to evaluate the effectiveness of a synthetic jet actuator (SJA) for flow control on a pitching airfoil. A NACA 0015 profiled airfoil was ramped up at various rates with concomitant surface-pressure acquisition. A self-contained synthetic jet actuator was positioned in the interior of the airfoil. Synthetic-jet-actuation parameters included the jet-momentum coefficient and the slot exit width. The behavior of the surface pressures is investigated as well as their integrated properties. The data suggest that the effect of the SJA is to delay the onset of the dynamic-stall vortex formation to higher incidence and in some cases, for the parameters and incidence range investigated, suppress it totally. However, in the instances when formed, the synthetic jet appears to increase the loading induced by the stall vortex. At low ramp rates, the synthetic jet forcing causes the formation of a stall vortex where the unforced data showed a psuedostatic stall-type behavior