The Effect of Accumulated Charges and Fluid Dynamics on the Helium Plasma Jet Array Behavior

This paper investigated the effect of accumulated charges and fluid dynamics on the helium plasma jet array behavior. The plasma jet array was composed of three individual plasma jets in a parallel arrangement. The dynamic evolution and the hydrodynamic interaction of plasma jets were observed under for adjacent jet-to-jet distances, pulse frequencies, and pulsewidths. The results showed that variation of the above parameters exerted an influence on the distribution of accumulated charges and gas flow, and thus controlled the outside and middle jet lengths. With a small pulse frequency and pulsewidth, the higher air fraction in the middle jet trajectory prevented its propagation and resulted in a shorter middle jet length. The increase of the pulse frequency or pulsewidth induced higher charge accumulation, and thus the deflection of the outside jets was more significant. At the same time, the gas flow channel showed a similar divergence and changed the air participation in the jet array, which explained a shorter middle jet length under a higher pulse frequency or pulsewidth. The results obtained in this work helped to understand the plasma jet interaction mechanism in the plasma jet array and to develop a uniform large-area discharge plasma.