Investigation on the Characteristics of Dielectric Barrier Surface Discharge Driven by Repetitive Nanosecond Pulses in Airflows

Recently, more and more attention has been drawn to nanosecond pulsed surface dielectric barrier discharge (NPSDBD) due to its potential applications in flow control. A study of the interaction between high-speed airflows and NPSDBD generated by different nanosecond waveforms is presented in this paper. The effects of airflows on the discharge characteristics, such as plasma morphology, discharge current, the inception voltage of discharge, are investigated at different pulse rise times and flow velocities. The results show that the NPSDBD sustained by pulses with a fast rise time ($\sim 20$ ns) is quasi-uniform, and relatively stable in the airflows. While the NPSDBD driven by pulses with a rise time more than 50 ns, it seems easier to be influenced by a flowing air of 60 m/s, with a filamentary pattern and a typical discharge current, which has two or more current peaks in the pulse front. In the case of pulses with slow rise time, the inception voltage of discharge increases with the flow velocity, but it almost remains constant in the case of fast rise time. In addition, the deposited energy of discharge generated by the pulses with slow rise time increases slightly with the influence of flowing air. The emission spectrum of NPSDBD is also examined. The variation of the emission spectrum with pulse waveforms is basically consistent with the different discharge behaviors driven by different pulse waveforms.