Effects of oxygen concentration on atmospheric-pressure pulsed dielectric barrier discharges in argon/oxygen mixture

Abstract

In this work, the effects of oxygen concentration on the atmospheric-pressure argon/oxygen pulsed dielectric barrier discharges (DBDs) have been numerically investigated based on a 1-D fluid model. The effects of oxygen concentration in the range below 5% on the important discharge properties of the argon/oxygen pulsed DBDs are systematically calculated and analyzed. The present work presents the following significant observations. The discharge current density still presents, in spite of oxygen addition, the form of two bipolar pulses in one period of the applied voltage, as occurred in pure noble gases. Especially, oxygen admixture affects basically only the first discharge, and the resultant characteristics are that the peak value of the current density reduces and the peak position moves in the direction of the time, when increasing oxygen concentration. Increasing oxygen admixture significantly raises both the breakdown voltage of the second discharge and the averaged electron temperature not only in the pulse duration but also in the time interval between the applied voltage pulses. The averaged dissipated power density reaches its maximum as the oxygen concentration is 3%. Also, increasing oxygen admixture effectively enhances the averaged particle densities of O+, O2(1Δg), and O3, but obviously reduces those of electron, Ar+, O, and O(1D). Under the considered oxygen concentrations, O2+ and O3− are the dominated oxygen-related charged species.