Performance Improvements in Wall-normal Momentum Injection with Axisymmetric Dielectric Barrier Discharge Plasma Actuators

Dielectric barrier discharge (DBD) plasma actuators have seen a strong interest in active flow control over the last two decades. Plasma synthetic-jet actuators (PSJAs) are DBD jets capable of producing zero-net mass flux momentum injection in atmospheric conditions with near instantaneous response and no moving parts. Due to the edge-normal momentum injection characteristics of PSJAs, most studies focused on surface wall jet configurations with spanwise geometries (see straight-edge, serrated, fingered electrodes). Opposing and annular geometries have been briefly explored for the purpose of wall-normal thrust by producing opposing flows, albeit with relatively low velocity and forcing.

We further examine the electro-mechanical characteristics of axisymmetric plasma synthetic jet actuators (APSJA’s) with improved dielectrics and larger diameters than previous studies, resulting in substantial improvements in velocity and momentum injection with comparable power consumption. We investigate entrained and injected flow behavior through experimental and numerical approaches Combined, this provides extended voltage-frequency-diameter-thrust relationships for APSJAs as well as finer intricacies including entrainment patterns, self-similarity, and jet dissipation. Combined with electrical current analysis, the APSJA is found to be an effective method of producing wall-normal momentum-injection.