Augmented Dielectric Barrier Discharge Plasma Actuators for Active Flow Control

Abstract

Electrohydrodynamic (EHD) devices have seen a strong surge in popularity for various applications, including virus inactivation, electrostatic particle collection, and, most interestingly, active flow control. The most promising EHD device for active flow control is a dielectric barrier discharge (DBD) plasma actuator due to its solid-state operation, fast response time, and easy integration. However, DBD actuators have not yet been developed for robust real-world applications. Much of the fundamental physics of DBD actuators remains unclear, and realistic applications of DBD actuators require significantly improved performance. This dissertation aims to improve our understanding of DBD plasma actuators and their complex underlying phenomena and use those insights to optimize them. First, we develop empirical models of critical DBD parameters such as thrust and power usage for standard two-electrode DBD actuators in quiescent, co-flow, and counter-flow wind conditions. Second, this work explores the underlying plasma-fluid mechanisms of a DC-augmented (DCA) DBD actuator with a positively or negatively biased third electrode. With novel DC augmentation insight, this work then explores an AC-augmented DBD for the first time. The AC augmentation illustrates a pathway for continuous DBD acceleration by demonstrating a pull action by a third electrode. Immediately building on the AC augmentation mechanism, this dissertation develops an optimized multi-stage DBD array with key geometric limits. The multi-stage DBD array generates significantly more thrust than previously reported DBD actuators with a thicker wall jet. Finally, the multi-stage DBD array is tested on a Clark Y airfoil in robust co-flow conditions at varying angles of attack. The results suggest an optimized DBD array can control an aerodynamic surface with significantly more control authority at more robust conditions than previously demonstrated.