Electrohydrodynamic force and aerodynamic flow acceleration in surface dielectric barrier discharge

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.