Influence of excitation voltage waveform on dielectric barrier discharge plasma aerodynamic actuation characteristics

Abstract

Plasma flow control, based on the plasma aerodynamic actuation generated by air discharge, is an active field in aerodynamics due to its potential application in performance improvement of future aircraft. In order to better understand the underlying physical mechanism of plasma flow control, it is important to investigate the relationship between the operating parameters and the plasma aerodynamic actuation characteristics. This paper reports the electrical, optical and mechanical characteristics of surface dielectric barrier discharge plasma aerodynamic actuation excited by microsecond and nanosecond high voltage waveforms. The nanosecond discharge is more diffuser than the microsecond discharge and the discharge current is much larger at the same applied voltage amplitude. The optical emission intensity of the nanosecond discharge plasma is stronger than that of the microsecond discharge plasma, while the rotational and vibrational temperatures of N _{2} in the nanosecond discharge plasma are less. In addition, the relative intensity of the first negative system of N_2^+ (B ^2 Σ _u^+ → X^2 Σ _g^+ ) and the second positive system of N_2 ( C^3 Π _u → B^3 Π _g ) is much less in the nanosecond discharge plasma. The velocity measurements indicate that the air flow induced by the nanosecond discharge plasma aerodynamic actuation is vertical to the dielectric surface, while that induced by the microsecond discharge actuation is parallel to the dielectric surface.