Characterization of nanosecond pulse driven dielectric barrier discharge plasma actuators for aerodynamic flow control

Abstract

Positive polarity nanosecond pulse driven dielectric barrier discharge (ns-DBD) plasma actuators are studied experimentally in quiescent atmosphere. Pulse energy and instantaneous pulse power (hereafter referred to as energy and power) are calculated using simultaneous voltage and current measurements. Electrical characteristics are evaluated as a function of peak voltage, pulse frequency, discharge length, and dielectric thickness. Schlieren imaging is used to provide a relative estimate of discharge energy that is coupled to the near surface gas as heat for the same parameters. Characteristics of the DBD load have a substantial effect on the individual voltage and current traces which are reflected in the energy and power values. Power is mainly dependent on actuator length which is inconsistent with schlieren data as expected. Higher per unit length energy indicates a stronger compression wave for a given actuator geometry, but this is not universally true across different actuators suggesting some constructions more efficiently couple energy to the gas. Energy and compression wave strength are linearly related. Higher pulse frequency produces higher energy but is primarily attributed to heating of the actuator and power supply components and not to an optimal discharge frequency. Both energy and wave strength increase as peak voltage to the power of approximately 3.5 over a substantial range similar to ac-DBD plasma actuators.