Modeling of reactive species interphase transport in plasma jet impinging on water

The interaction between low-temperature atmospheric pressure plasma and water is of primary relevance to an increasing number of applications, from water treatment to medicine. The interaction between an argon plasma jet and water is investigated using a three-dimensional (3D) time-dependent computational model encompassing turbulent gas flow and induced liquid motion, gas-water interface dynamics, multiphase species transport, and gas- and liquid-phase chemical reactions. A single-field approach based on the volume-of-fluid (VoF) method together with conditional volume averaging (CVA), is used to consistently describe the dynamics of the interface together with interfacial reactive mass transfer. Three CVA-based interface species transport models, based on arithmetic, harmonic, and unified mixture species diffusivities, are evaluated. Simulations of a plasma jet impinging on water at different gas flow rates are presented. The resulting deformation of the interface and the production and accumulation of hydrogen peroxide, reactive oxygen, and nitrogen species corroborate prior findings in the research literature showing that higher jet velocities and associated increased interface deformation led to the enhanced transport of reactive species across the plasma-water interface. The VoF-CVA approach appears promising for the modeling of general plasma-liquid multiphase systems.