Numerical simulation of atmospheric-pressure helium glow discharge with liquid electrode considering gas and liquid dynamics

DC atmospheric-pressure glow discharge with liquid electrodes is a type of stable atmospheric-pressure non-equilibrium plasma. The DC discharge with continuous ionization results in high plasma densities, and consequently causes gas heating and convection, and even liquid convection. In this work, we performed numerical simulation of atmospheric-pressure helium glow discharge with liquid electrode considering gas and liquid dynamics. The simulation was divided into two parts, gas discharge simulation with liquid electrode, and gas/liquid fluid simulations. In the former, continuity equations for charged and neutral species in the gas and current continuity equations are solved simultaneously with Poisson’s equation. In the latter, the fluid equations were computed for gas and liquid. Joule heating is considered for both gas and liquid, and so-called ion wind is considered in the gas. The change in gas density due to gas temperature increase is reflected in the calculation of gas discharges. Due to the difference in the time constants of the gas discharge and gas/liquid flows, the calculations were separately performed, alternately passing parameters until convergence. Although the calculation results were within the expected range, details were revealed in absolute values.