Flow-Control-Induced Vibrations Using Pulsed DBD Plasma Actuators

Abstract

This paper describes flow-control-induced vibrations using pulsed dielectric barrier discharge (DBD) plasma actuators, in which boundary layer separation on a structure is actively controlled to produce periodic loads that lead to its vibration. The concept is intended for energy generation and is demonstrated experimentally using a one-degree-offreedom pivoted cylindrical body, mounted vertically within a blow-down wind tunnel. Subcritical Reynolds numbers, less than 10 5 , were considered where typical shedding frequencies were several times larger than the system natural frequency. Static deflection experiments were performed to determine the maximum imposed aerodynamic loads as a function of control parameters and these were complimented with flow-field measurements. Periodic loading of the cylinder was achieved by periodic modulation of the actuator. Large amplitude oscillations were observed when the modulation frequency was close to the system natural frequency. In contrast to natural vortex induced vibration, the large amplitude oscillations were achieved by alternating dynamic separation and attachment of the boundary layer. Estimation of the transient loads was performed using a system identification technique and the power generated by the system was estimated on the basis of a piecewise linear model. Peak estimated power coefficients were relatively small (0.042) but the system is amenable to up-scaling because the power coefficient increases with the squareroot of the system dimensions.