Electrohydrodynamic force and aerodynamic flow acceleration in surface dielectric barrier discharge

TLDR

Surface dielectric barrier discharges (DBDs) in the glow regime, sustained by ion‑induced secondary electron emission and volume ionization, have been proposed as actuators for aerodynamic flow control. Using a two‑dimensional fluid model, the authors calculate the force per unit volume exerted on the flow by momentum transfer from charged particles to neutrals in the surface discharge. The resulting force resembles the electric wind of a corona discharge, is concentrated in the cathode sheath along the dielectric, is much stronger than in a DC corona but lasts less than 100 ns per pulse, yielding time‑averaged forces comparable to the corona case under the studied conditions.

Abstract

Surface discharges created in dielectric barrier discharge (DBD) configurations have been proposed as actuators for flow control in aerodynamic applications. We focus on DBDs operating in a glow regime, i.e., where the discharge is sustained by ion-induced secondary electron emission from the surface and volume ionization. After a brief discussion of the force per unit volume acting on the flow and due to the momentum transfer from charged particles to neutral molecules, we present calculations of this force based on a two-dimensional fluid model of the surface discharge. We show that this force is of the same nature as the electric wind in a corona discharge. However, the force in a DBD is localized in the cathode sheath region of the discharge expanding along the dielectric surface. While its intensity is much larger than the analogous force in a direct-current corona discharge, it is active during less than one hundred nanoseconds for each discharge pulse and the time-averaged forces in the two cases are comparable, at least for the conditions we have chosen for this study.