Effect of pulse width on the characteristics of a dielectric barrier discharge plasma actuator driven by high-voltage pulses

Abstract

In this study, high-voltage pulses are used to drive dielectric barrier discharge plasma actuators (DBDAs) for flow control purposes. The rising/falling edges of the pulse are kept nearly constant in nanosecond timescale, while the pulse width is varied from nanosecond to microsecond timescale. The impact of pulse width on the characteristics of the DBDA is investigated experimentally with a high-speed schlieren system and a high-fidelity force balance. In the case of small pulse width, a pressure wave propagating at the local speed of sound is produced each time at discharge ignition, and a vertical jet plume is induced after multiple discharge pulses due to heat accumulation (buoyancy effect). As a comparison, for cases with large pulse widths, two pressure waves are created sequentially with a time lag close to the pulse width, and a starting vortex followed by a near-wall jet is produced, demonstrating that significant momentum similar to that of DBD driven by sinusoidal high voltage has been imparted to the near-wall flow. A proportional increase of the induced body force with the cube root of the pulse width is demonstrated, while the pulse energy decreases nonlinearly as the pulse width increases. The maximum body force of 2.49 mN m−1 is reached at a pulse width of 380 μs.