Abstract
About the flow around an airfoil, it has been known that flow separation occur behind it. And we have used various actuators such as riblet and vortex generator to control the flow. But these actuators have some drawbacks, for example they have complex structure, noise and low energy efficiency. Recently, as an alternative of these actuators, active controlling devices such as DBD(Dielectric Barrier Discharge) Plasma Actuator have been studied, which can overcome some drawbacks mentioned above. The purpose of this study is to suppress flow separation around the airfoil with DBD Plasma Actuator by generating longitudinal vortex and to confirm the effect of drag reduction acting on airfoil. The experiments were conducted into wind tunnel at constant temperature. The airfoil type is NACA0021. The flow velocity is measured with a Constant Temperature hot-wire Anemometer(CTA), pitot tube and precision micro manometer. The mainstream velocity is 1.8[m/s], Reynolds number is 10000, angle of attack is 12[deg], applied voltage is 5.0[kV], applied frequency is 4.0[kHz]. It was found that the longitudinal vortex generated by DBD Plasma Actuator enabled suppression of separation around the airfoil. The maximum drag reduction rate was about 9[%].
