Numerical study of atmospheric-pressure argon plasma jet propagating into ambient nitrogen

In this paper, a two-dimensional fluid model is used to study the properties of atmospheric-pressure argon plasma jet propagating into ambient nitrogen driven by a pulsed voltage, emphasizing the influence of gas velocity on the dynamic characteristics of the jet. The simulation results show that the argon jet exhibits a cylindrical shape channel and with the increase of propagation length, the jet channel gradually shrinks. The jet propagation velocity varies with time. Inside the dielectric tube, the plasma jet accelerates propagation and reaches its maximum value near the nozzle. Exiting from the tube, the propagation velocity of the plasma jet quickly decreases and when approaching the metal plane, the decrease of jet velocity slows down. The increase of gas speed leads to the variation of the jet spatial distribution. The electron density presents a solid structure at lower gas flow speeds, whereas an annular structure can be observed under the higher gas flow velocity in the ionization head. The jet length increases with the gas flow velocity. However, when the flow velocity exceeds a critical value, the increased rate of the plasma jet length becomes slow. Additionally, the influence of the gas flow speed on the production and transport of the reactive species is also studied and discussed.