Active Separation Control over a NACA0024 by DBD Plasma Actuator and FBG Sensor

Dielectric barrier discharge plasma actuators (DBD-PA) and fiber Bragg grating (FBG) sensors have been investigated for active control of flow separation around a NACA0024 airfoil. Tangential jets were produced in the vicinity of the DBD-PA slightly aft of the leading edge of the airfoil. The flow separation control ability was evaluated at low Reynolds number in an open-circuit wind tunnel. Phase- and time-averaged velocity distributions around the airfoil were measured using Particle Image Velocimetry, and the flow separation control ability of the DBD-PA was assessed at 8°, 12° and 16° angle of attack. An FBG sensor was attached to a chord-wise cantilever near the trailing edge of the airfoil on the pressure surface. This was used to measure strain fluctuations in the cantilever root due to flow-induced oscillations. The feasibility of this system to detect flow separation was studied, where the standard deviations of strain fluctuations significantly increased when the flow was separated. This was utilized in an open-loop control system to detect flow separation by FBG then apply active control with the DBD-PA to reattach the flow.