Numerical Studies on the Downstream Uniformity Modulation of Atmospheric Pressure Cold Plasma Jet Array via Gas Flow Controlling Strategy

Atmospheric pressure plasma jets (APPJs) have attracted considerable interests due to their low-temperature and easily controlled features. In order to cover a larger area for broader applications, spatially extended atmospheric plasma arrays are designed and constructed by a number of packed plasma jets. Despite their outstanding stability and flexibility, it remains a challenge for the jets to form large-scale uniformity on downstream substrates due to complex electrical and hydrodynamic interactions. In this paper, we use a 2-D temporally evolving code coupling electric, flow, and temperature fields, as well as chemical reactions to study synergistic effects of the multi-fields coupling on discharge and propagation characteristics of the jet array based on a USim software framework. The influence of gas flow and a substrate downstream on the plasma jets dynamics and uniformity are investigated by the model. Also, essential strategies for uniformity modulation are acquired. Results show that the balanced evolution of the ionization process and the effective merging of discharge channels could be realized by modulating the gas flow field. Therefore, a homogeneous distribution of plasma downstream can be obtained by adjusting the gas flow field properly, which provides a new efficient way for the uniformity control in the field of plasma processing.