Experimental study on dielectric barrier discharge actuators operating in pulse mode

An experimental investigation is performed on the operation of dielectric barrier discharge plasma actuators used as manipulators of secondary and unsteady flow structures such as boundary layer instabilities or shedding vortices. The actuators are tested mainly in pulse mode. High sample rate hot-wire measurements of the induced velocity field downstream of the actuator are taken for the cases of pulse actuation in still air as well as in a laminar boundary layer. Complementary voltage and current measurements are taken to calculate power consumption. Additionally, a study on the influence of the pulse frequency and duty cycle of actuation is performed. Results show the effectiveness of plasma actuators in inducing fluctuating components of velocity when operated in pulse mode. Spectral analysis reveals the connection between the actuator driving signal and the induced flowfield. The magnitude as well as the consistency of the resulting fluctuating field are dependent on both the duty cycle and the pulse frequency. An empirical operational envelope based on phenomenological observations is proposed, for the use of the actuators at specific flow and operational conditions given in the paper