Post-stall flow control using nanosecond pulse driven dielectric barrier discharge plasma actuators

The efficacy of thermal perturbations generated by nanosecond pulse driven dielectric barrier discharge (ns-DBD) plasma actuators for post-stall flow control is explored on a NACA 0012 airfoil. Baseline and controlled flow fields are studied using static pressure measurements, particle image velocimetry and constant temperature anemometry. Experiments are primarily performed at Re = 0.74 10⁶ (U _∞ = 40 m s^-1) and α= 18. Three regimes of forcing are identified corresponding to separation control (0.92 < F ⁺ < 1.52), bluff body shedding (0.23 < F ⁺ < 0.92) and an impulse-like response (F ⁺ < 0.23). The response of the flow to a single high voltage pulse is also examined and compared to other studies of transient separation control. Results show that the global structure of the controlled flow is not specific to ns-DBD plasma actuator forcing. Rather, it is the local behavior of the ns-DBD that results in control authority at conditions that are challenging for the majority of active flow control actuators that rely on zero net mass flux momentum addition. The implications of these findings as well as open questions and suggestions for future work are discussed.