Three-Dimensional Coupled Fluid-Droplet Model for Atmospheric Pressure Plasmas

A 3D coupled fluid–droplet model is developed specifically to characterize the significance of droplet-plasma interaction at atmospheric pressure. The liquid droplet introduces a perturbation in atmospheric pressure plasma (APP) and under many conditions, the behavior of this perturbation is not clear during transport in PlasmaStream system. In this study, we identify the importance of ionization mechanism in two-phase flow. The affect and spatial expansion of vaporization in discharge plasma depend on the flow rate of liquid precursors. Penning ionization is recognized as the leading process along the pulse of evaporating droplets as compared to other ionization processes that explain the relevance of small nitrogen impurities. The influence of different precursors, such as hexamethyldisiloxane, tetraethyl orthosilicate and water is described by contrasting the implication of the evaporation process. Finally, we validate the numerical simulation by comparison with the experimental observations of droplet size distributions using a laser diffraction particle size analysis technique as a part of APP jet deposition system.