Degradation in aluminium and copper foil electrodes in surface dielectric barrier discharges (sDBDs), operating in ambient air, is studied using various microscopic methods. It is determined that difference in the oxidation dynamics for these two materials lead to different morphology of the exposed electrode edge. The structure of the exposed electrode, in its turn, affects the dynamics of the microdischarges and the main integral electrical characteristics of the sDBD: power input, charge amplitude, shape of the charge−voltage cycle plot.

Breakdown voltage for surface dielectric barrier discharge ignition in atmospheric air has been measured for different parameters of the dielectric barrier, exposed electrode mounting, and supply voltage frequency. The analytical model of the discharge onset has been developed. It reveals that the discharge breakdown voltage is proportional to the square root of the dielectric barrier thickness and weakly depends on dielectric relative permittivity. The trajectory of discharge breakdown is managed mainly by gas properties and its density; it does not depend on dielectric barrier parameters and the breakdown voltage value. The analytical solution is in good agreement with the obtained experimental data and indicates the validity of the 2D approach for the breakdown process in the case of discharge between the strip and flat electrodes separated by a dielectric barrier.

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In this study, a new type of dielectric barrier discharge plasma actuator for boundary layer control, based on the controllable inhomogeneity of the discharge along the exposed electrode, is developed. The structure of the flow, generated by the isolated groups of microdischarges, was studied in detail in quiescent conditions. In the two-dimensional laminar boundary layer, the flow structure downstream of the actuator was studied for various sweep angles of the electrode. The equivalent model of the actuator, including the force and heat sources, is formulated based on the analysis of the flow created by the actuator in quiescent conditions. The model is verified by simulating the flow downstream of the actuator in two-dimensional boundary layer. As a final step, the applicability of the localized microdischarge group actuator for active transition control on a swept wing was studied. The generation of a cross-flow mode by the actuator was demonstrated in numerical simulation for low-velocity experiment conditions.

The properties of microdischarges (MDs) in a surface barrier discharge, operating on various electrode materials are studied by current measurements and submicrosecond photography. Based on these data, the dynamics and statistics of MDs at various phases of the applied voltage are analyzed. It is shown that differences in oxide layer structure on the electrode edge strongly affect the spatial organization of the discharge and the properties of the current pulses.

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