Three-Dimensional Modelling of an Atmospheric Pressure Glow Discharge with Liquid Anode

Plasma-on-liquid interaction is a plasma science frontier with applications in medicine, water remediation, agriculture, and materials processing, among others. This work presents the computational modelling and simulation of a direct-current atmospheric pressure glow discharge (APGD) in helium with a liquid anode. The APGD is sustained by 30 mA current within a pin-to-liquid configuration with 8 mm inter-electrode spacing, following the experimental investigations by Yang et al.[1]. The APGD is studied using a multiphase model encompassing thermal and chemical non-equilibrium plasma and liquid flow phenomena. The model includes the conservation equations for total mass, momentum, chemical species, electrons and heavy-species thermal energies, and electric charge[2]. The fully-coupled, highly non-linear model is discretised using the non-linear Variational Multi-Scale (VMS
n
) Finite Element Method (FEM)[3], which has demonstrated to be suitable for capturing self-organisation phenomena in arc discharge simulations and other fluid flow problems. Modelling results compare the characteristic properties of the plasma column with a liquid anode against those of a metal anode.