Flying wing flow separation control by microsecond pulsed dielectric barrier discharge at high Reynolds number

In this study, a microsecond pulsed dielectric barrier discharge (μs-DBD) plasma actuator is utilized to improve the aerodynamic performance of a flying wing. The wind tunnel experiments were conducted by the μs-DBD plasma actuator at a high Reynolds number (Re = 2.61 × 106). The effects of discharge position and pulse frequency on the flow control performance were studied by force measurements. The particle image velocimetry test was used to reveal the influence of plasma actuation on the detailed velocity field at the suction side of the flying wing. Results show that plasma actuation can significantly improve the aerodynamic performance of the flying wing under high Reynolds number. The best flow control effect is obtained when the plasma actuator is mounted near stagnation point (0.1% C). There is an optimal excitation frequency (100 Hz) at Re = 2.61 × 106 (corresponding to the wind speed of 70 m/s), at which the flow instability can be effectively excited. In the optimal situation, the relative improvement of the maximum lift coefficient reaches 20.51% and the stall angle is delayed by 6°. The flow control performance is mainly achieved at the outer part of the wing because the flow separation develops gradually from the wing tip to the root. These experimental results contribute to the free flight test in the wind tunnel and the flight test in real air conditions.