Plasma-Based Dynamic Stall Control and Modeling on an Aspect-Ratio-One Wing

Quasi-static and dynamic stall control experiments, using dielectric barrier discharge plasma actuators, were performed on a square-tipped aspect-ratio-one wing, with a NACA 0015 profile, under harmonic pitching, at a Reynolds number of 3×105. Relatively low 풪(1) and relatively high 풪(10) pulse-modulated reduced excitation frequencies were introduced at the leading edge; the former produced the largest poststall lift improvements, whereas the latter produced the highest maximum lift. A reduced frequency, based on laminar separation bubble shedding, was enlisted to explain the differences between the two results. Under conditions of dynamic pitching, evidence of a dynamic stall vortex was absent, due to its interaction with the strong tip vortices, consistent with prior experimental and numerical investigations. As a general rule, performance benefits produced by excitation under quasi-static conditions were reproduced under harmonic pitching. Low-order dynamic stall and dynamic stall control models, based on a modified version of the Goman–Khrabrov delta-wing concept, were evaluated. Model constants were obtained from quasi-static data sets, and a single baseline dynamic case was employed to determine the time constants. The model produced excellent results for both baseline and controlled cases, which was attributed to similar lift and stall mechanisms exhibited by delta and rectangular low-aspect-ratio planforms.