Self-consistent modeling of a surface AC dielectric barrier discharge actuator: In-depth analysis of positive and negative phases

Abstract

We report on a detailed numerical study of the two-phase operation of a surface Alternating Current (AC) Dielectric Barrier Discharge (DBD) actuator. We showcase that when the quasi-periodic regime has been established, residual volume and surface charges play an important role on the discharge evolution strongly coupling the positive and negative phases. It is shown that the quasi-neutral streamer discharge found on the positive phase serves as both a positive and negative charge generator and acts as a virtual anode. As the streamer is not attached to the dielectric surface, most of the surface charging occurs during its after-burn (relaxation) phase. The positive surface charge leads to an distant zone of high electric field and thus ion drift but also interacts majorly with the negative discharge phase. During the latter, microdischarges form near the active electrode and an intense cathode layer feeds with charges the discharge volume. Each microdischarge is followed by a plasma layer formation attached to the dielectric layer expanding further at each repetition until it occupies a volume linked to the streamer elongation length and positively charged surface portion. The strong coupling between the positive and negative phases along with the strong impact of the streamer discharge on both suggest implications that have been ignored so far in terms of EHD force production and its spatiotemporal distribution.

Flow reversal in millimetric annular DBD plasma actuator

“…The negatively charged dielectric repels the positive ions and a thin negative ion layer forms attached to the dielectic surface. This is in very good agreement with the numerical work of [20,21] where similar behavior has been observed in linear DBDs -the reader can find additional details on the (intense) microdischarge evolution in these references. On the other hand, for the D = 1 mm case, a smaller plasma volume can be observed.…”

“…This model has been qualitatively verified for atmospheric pressure plasma discharges [16], and has been used for detailed descriptions of linear DBD plasma actuators and related EHD force production [20,21]. Models which utilise the same assumptions have been extensively validated with experimental findings [22,23].…”

Streamer dynamics and charge self‐erasing of two counter‐propagating plasmas in repetitively pulsed surface dielectric barrier discharge

“…With the development of the transitional streamer, more and more positive charges are deposited on the dielectric surface. At the same time, the applied pulse decreases to a critical value which is smaller than that of the electric potential formed by the accumulated charges, and the dielectric surface is regarded as a virtual anode [52]. Then, two negative discharges (secondary streamers) are produced from the edge of the two HV electrodes and propagate along the dielectric surface.…”

Polyimide Surface Dielectric Barrier Discharge for Inactivation of SARS-CoV-2 Trapped in a Polypropylene Melt-Blown Filter

“…Two types of discharge have been observed in the SDBD: streamer discharge and microdischarge, which is called two-phase discharge. 38 Two-phase discharge has positive and negative phases. In the positive phase, electrode 1 exposed to the atmosphere acts as an anode.…”