Experimental Study of Dielectric Barrier Discharge Driven Duct Flow for Propulsion Applications in Unmanned Aerial Systems

The dielectric barrier discharge (DBD) has been studied significantly in the past two decades for its applications to various aerodynamic problems. The most common aerodynamic applications have been stall/separation control and boundary layer modification. Recently several researchers have proposed utilizing the DBD in various configurations to act as viable propulsion systems for micro and nano aerial vehicles. The DBD produces stable atmospheric-pressure non-thermal plasma in a thin sheet with a preferred direction of flow. The plasma flow, driven by electrohydrodynamic body forces, entrains the quiescent air around it and thus develops into a low speed jet on the order of 10^-1 to 10¹ m/s. Several researchers have utilized DBDs in an annular geometric setup as a propulsion device. Other researchers have used them to alter rectangular duct flows and directional jet devices. This study investigates 2-D duct flows for applications in micro plasma thrusters. The DBD actuators are located on the convergent intake section of the thruster which allows for variation of the effective flow entrainment angle for maximal thrust and a second set of actuators are located in the constant area portion of the duct. DBD operating parameters and thruster geometry were varied during experimentation to determine optimal conditions for maximized net thrust output. Flow measurements were collected via particle image velocimetry (PIV) and correlated to DBD operating parameters and thruster geometry.