Control of leading edge separation on airfoil using DBD plasma actuator

Abstract

This study deals with the separation control of an airfoil when a dielectric barrier discharge (DBD) plasma actuator is mounted on its leading edge. The experiments were performed at Reynolds number, Re ≈ 67,000 in an external airflow of 10 m/s. The DBD plasma actuator was installed at x/c = 0.025 of a NACA0015 airfoil with a 100-mm chord and 150-mm width. Flow visualization, lift force and velocity measurements were conducted with on and off modes of the actuator (pulse-modulated drive). We found that the application of pulse modulation condition was able to delay a stall up to angle of attack α =17° compared to the Duty = 100% (α =15°). At α =17°, the maximum lift coefficient C l was obtained for a non-dimensional pulse modulation frequency St of 4.0. With an increase in α, the lift coefficient C l decreases sharply after reaching a maximum, which is entirely different from the case of St = 0.6, where the value of C l falls gradually. For a high angle of attack (α =18°) that exceeds the maximum C l , St = 0.6 produces a better lift improvement than when St = 4.0. Our results showed that the separation when St = 4.0 is larger than that when St = 0.6. In addition, we also found that there is an optimum actuation time of about 0.25 ms.

Recent advancements toward the understanding and control of turbulent flows (Summary of ICJWSF2013)

“…The efforts, for the last several years at the Institute of Space and Astronautical Science, JAXA, for better understanding of the flow control mechanism of DBD plasma actuators are summarized, showing the effectiveness of the devices (Fujii, 2013). The applications of plasma actuators to the separation control of airfoils are discussed with the results of LES and of experiments Daud, et al, 2013). The counter-type plasma actuator inducing streamwise vortex pair is shown to be effective for controlling the separation on the surface of a circular cylinder (Funaoka, et al, 2013).…”