Trailing-edge plasma flow control enhances unsteady lift on pitching aerofoils

Abstract

Leading-edge vortices (LEVs) are essential for achieving high lift and manoeuvrability in biological and bio-inspired flyers. To promote LEV growth and enhance unsteady lift, this study employs a dielectric-barrier-discharge plasma actuator on a pitching NACA 0015 aerofoil. Experiments are conducted at Reynolds numbers (Formula presented) of (Formula presented) and (Formula presented), with a pitching amplitude of 30°, and reduced frequencies k of 0.1–0.3. The actuator is placed at the trailing-edge, where its interaction with the LEV influences vortex growth. We observe an enhancement in lift both before and after LEV formation, achieving a 43% increase in time-averaged lift at (Formula presented), (Formula presented). Pressure and flowfield measurements reveal three key effects: (1) enhanced chordwise velocity, (2) increased LEV growth rate, and (3) larger LEV circulation with slower advection. These findings demonstrate an approach to controlling LEV dynamics and hold promise for improving aerodynamic performance in unsteady flow applications.