On the Mechanisms of Electroaerodynamic Propulsion via Force Analysis

Electroaerodynamic (EAD) propulsion is attractive as atmosphere propulsion due to the unique properties of silence and combustion-free emission. EAD propulsion uses two electrodes as an engine to generate propulsive thrust, with the produced thrust being a combination of various forces acting on the electrode. Understanding the effect of those forces on EAD thrust generation is crucial for discovering the physical origin of EAD thrust and advancing this technology for practical applications. In this study, using a wire-to-cylinder EAD system, the effect of each force on the thrust generation is quantified and analyzed. First, EAD thrust is the net force of electrostatic forces and aerodynamic forces acting on the electrodes. Second, electrostatic forces are comprised of electrostatic attraction acting on the collecting electrode and electrostatic repulsion acting on the emitting electrode, both exerted by the discharge-induced ions. Third, the electrostatic attraction on the collecting electrode, rather than the electrostatic repulsion on the emitting electrode, plays a significant role in EAD thrust generation. Lastly, the aerodynamic force, manifested as the drag force arises when the ionic wind passes through the electrodes, leading to a reduction in the produced EAD thrust. Specifically, the drag force primarily originates from the pressure drag generated on the collecting electrode. These fundamental findings facilitate structural design and optimization methods for electrodes to achieve high EAD thrust, with a particular focus on enhancing the aerodynamics of the collecting electrode and reducing the radius of the emitting electrode.