Optimization of Multi-Electrode Dielectric Barrier Discharge Arrays for Active Flow Control*

Dielectric barrier discharge (DBD) plasma actuators for active flow control offer several advantages over conventional flow control techniques, including no moving parts, instantaneous response, and quiet operations. However, DBD actuators are limited to low-speed applications and require further optimization. The addition of DBD in series electrodes can improve the thrust of and increase the area averaged the density of the overall system. Optimization of a multi-DBD array requires adjusting AC phase shift and streamwise spacing over a range of applied voltages and frequencies. Direct thrust and fluid velocity measurements as a function of electrical parameters are presented for two- and three-stage arrays. A multi-DBD array with out-of-phase AC electrodes provides significantly more thrust than previously reported multi-DBD systems. It is found to scale well for geometric constraints. This optimization allows DBD plasma actuators to increase the trust density and modify a fluid system more effectively.