Role of surface discharge dynamics in the generation of electrohydrodynamic force: toward performance improvement of dielectric barrier discharge plasma actuators

Dielectric barrier discharge (DBD) plasma actuators are devices that actively control the airflow using nonequilibrium atmospheric-pressure plasmas, showing promise for practical applications in the field of aerospace engineering. Numerous studies have revealed the dynamics of surface discharge and the process of generating electrohydrodynamic (EHD) force in detail. The performance of DBD plasma actuators has improved continuously over the past 20 years. However, there is a need for further improvement in EHD force generation to enable the practical applications of DBD plasma actuators. In this review, we provide insights that contribute to the development of a high-performance DBD plasma actuator by reviewing previous studies focused on revealing the surface discharge and EHD force generation processes. The foundations of the discharge process in DBD plasma actuators are briefly described from the perspectives of experiments and numerical simulations. We also reviewed various strategies for improving EHD force generation by optimizing the geometric structure and the applied voltage waveform as well as by controlling the surface charge accumulation. Improving EHD force generation and its efficiency is a fundamental research area to realize the practical applications of a novel active airflow control device that uses nonequilibrium plasmas.