A large-scale multiple dielectric barrier discharge actuator based on an innovative three-electrode design

For about 10 years, surface dielectric barrier discharges (DBDs) have been widely used as plasma actuators in subsonic airflow control applications. However, the extension length of a single surface DBD is limited to about 2 cm, which could restrict its use to small-scale applications. One way to extend the plasma actuation surface consists of using several single surface DBDs in series, energized by zero phase delayed or phase shifted high voltages. However, the mutual interaction between successive discharges affects the benefits of such standard multi-DBD actuators. This paper deals with a new design electrode for large-scale flow control applications. It consists of replacing each single two-electrode DBD by a three-electrode DBD where the third electrode acts as a shield between two successive DBDs. Experimental measurements by laser doppler velocimetry, pressure probe and time-resolved particle image velocimetry show that the mutual interactions can be strongly reduced, resulting in a constant electric wind velocity above the multi-DBD actuator.