Dynamic stall control over a rotor airfoil based on AC DBD plasma actuation

Abstract

At present, the control capability of dielectric barrier discharge (DBD) plasma actuation covers the flow velocity range of helicopter’s retreating blades, so it is necessary to extend it to the dynamic stall control of rotor airfoils. A DBD plasma actuator was adopted to control the dynamic stall of an oscillating CRA309 airfoil in this paper. The effectiveness of alternating current (AC) DBD plasma actuation on reducing the area of lift hysteresis loop of the oscillating airfoil was verified through pressure measurements at a Reynolds number of 5.2 × 105. The influence of actuation parameters on the airfoil’s lift and moment coefficients was studied. Both steady and unsteady actuation could effectively reduce the hysteresis loop area of the lift coefficients. The flow control effect of dynamic stall was strongly dependent on the history of angle of attack. Compared with the steady actuation, unsteady actuation had more obvious advantages in dynamic stall control, with reducing the area of lift hysteresis loop by more than 30%. The effects of plasma actuation on the airfoil’s flow field at both upward and downward stages were discussed at last.

Rotor performance enhancement by alternating current dielectric barrier discharge plasma actuation

“…When the pulsemodulated voltage was applied to the DBD actuator, the actuation is cycled on and off with an unsteady period, thus, unsteady plasma actuation is generated with a series of unsteady vortices moving along the wall surface. When DC=100%, the actuator is driven by continuous AC voltages and steady plasma actuation can be generated with a tangential jet along the wall [14].…”

Effect of spanwise groove on the dynamic stall characteristics of an airfoil

“…The unsteady AC DBD plasma actuator on the other hand could reduce the area of hysteresis loop by 30% at Re = 5.0 × 10 5 , for CRA309 airfoil. 31…”

“…The control of dynamics stall can be achieved through active flow control mechanism such as dielectric barrier discharge (DBD) plasma actuators. 21,[31][32][33] Singhal et al reported that an increase in the frequency of plasma actuation reduces the oscillatory behavior in the lift curve of NACA 0015 and the oscillations are completely wiped out for actuation Strouhal number of 2 and more. 33 These high frequency plasma actuations also reduce the area of hysteresis loop and the strength of DSV.…”

“…The unsteady AC DBD plasma actuator on the other hand could reduce the area of hysteresis loop by 30% at Re = 5.0 × 10 5 , for CRA309 airfoil. 31 Passive flow control mechanisms are preferred over active ones due to simplicity in design and lesser payload. Spanwise surface groove is one of the popularly used flow control mechanism used to control static aerodynamic characteristics of airfoil at low Reynolds number.…”