Localized micro-discharges group dielectric barrier discharge vortex generators: Disturbances source for active transition control

Abstract

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.

Transition control in a three-dimensional boundary layer at elevated free stream turbulence using dielectric barrier discharge

“…Он состоял из внешнего коронирующего электрода (алюминиевая фольга шириной 23,5 мм, длиной 380 мм и толщиной вместе с клеящим слоем 15 мкм), наклеенного на керамическую (оксид алюминия) пластину толщиной 1 мм, под которой размещался секционированный ответный электрод. Конструкция актуатора подробнее описана в [7]. В большинстве измерений ДБР-актуатор питался синусоидальным напряжением амплитудой 2,5 кВ и частотой 65 кГц.…”

Measurement of flow fluctuations induced by a dielectric-barrier-discharge plasma actuator using hot-film sensors

“…3 The application of an accurate electronic force balance to measure the plasma-induced force has been demonstrated too. 4 The effects of plasma actuator on the fluid in the vicinity of the electrodes are further measured by means of electrical voltage and light emission measurement, 5,6 smoke flow visualizations, 7,8 hot-wire probe, 9,10 wall pressure measurement, 11,12 particle image velocimetry (PIV), 11,[13][14][15][16][17] laser Doppler velocimetry (LDV), 15 laser induced fluorescence (LIF), 18 and Schlieren techniques 19,20 to name a few. Kotsonis 21 provides a comprehensive review of experimental studies on plasma actuators using a variety of diagnostic methods.…”

Damping of the longitudinal streak in the boundary layer by ‘plasma panel’ actuator

“…This work describes the results of development and testing of the plasma actuator, based on the group of microdischarges (MD) in DBD, localized by sectioning the actuator buried electrode. The concept itself was independently studied by several groups in the attempts to develop the virtual roughness elements to control the cross-flow instability [7,14,15]. The detailed analysis of the flow structure, generated by an isolated MD group, can be found in [14,15].…”

“…The concept itself was independently studied by several groups in the attempts to develop the virtual roughness elements to control the cross-flow instability [7,14,15]. The detailed analysis of the flow structure, generated by an isolated MD group, can be found in [14,15]. It is shown that a key structure formed downstream of the spanwise limited discharge region is a pair of counter-rotating longitudinal vortices, localized near the wall.…”

“…In recent work, the electrode system described in [15] was expanded to the 'plasma panel' configuration, where the potential of an individual section of the buried electrode can be electronically controlled. This allows us to change the spanwise forcing configuration, adjusting it to positions of the oncoming disturbances.…”