Multi-Electrode Dielectric Barrier Discharge Actuators: Geometrical Optimization of High Power Density Array
Dielectric barrier discharge (DBD) plasma actuator arrays have been suggested as active flow control devices due to the robust electrohydrodynamic (EHD) force generation in variable atmospheric conditions. DBD plasma augmentation schemes allow for significant performance improvements. However, the transitions to sliding discharge or counter-flow discharge limit their use in high-power arrays. Here, we experimentally demonstrate the performance of a scalable DBD array for two alternating phases of air-exposed electrode configuration. Plasma emissions, direct thrust, velocity profiles, and power consumption measurements of the DBD array reveal that cross-talk between DBD stages can be eliminated to create high-power density actuators. AC augmentation of plasma provides additional gains in thrust; however, the transition to sliding and filamentary discharge reveals geometric limits when increasing the array power density. Introducing a segmented electrode with a resistor delays the onset of adverse sliding and filamentary discharge, allowing it to operate at higher voltage inputs. An optimized four-stage DBD array generated thrust > 250 mN/m with a wall jet thickness > 15 mm, enabling a broader range of flow control applications.