Geometry optimization of linear and annular plasma synthetic jet actuators

Abstract

The Electro-Hydro-Dynamic (EHD) interaction induced in atmospheric-pressure air by a surface Dielectric Barrier Discharge (DBD) actuator has been experimentally investigated. Plasma Synthetic Jets Actuators (PSJAs) are DBD actuators able to induce an air stream, perpendicular to the actuator surface. These devices can be used in the aerodynamics field to prevent or induce flow separation, modify the laminar to turbulent transition inside the boundary layer, and stabilize or mix air flows. They can also be used to enhance indirect plasma treatment effects, increasing the reactive species delivery rate onto surfaces and liquids. This can play a major role in plasma processing and chemical kinetics modelling, where only diffusive mechanisms are often considered. This paper reports on the importance that different electrode geometries can have on the performance of different PSJAs. A series of DBD aerodynamic actuators designed to produce perpendicular jets have been fabricated on 2-layer printed circuit boards (PCBs). Linear and annular geometries have been considered, testing different upper electrode distances in the linear case and different diameters in the annular one. AC voltage supplied at 11.5 kV peak and 5 kHz frequency has been used. Lower electrodes were connected to ground and buried in epoxy resin to avoid undesired plasma generation on the lower actuator surface.Voltage and current measurements have been carried out to evaluate the active power delivered to the discharges. Schlieren imaging allowed to visualize the induced jets and gave an estimate of their evolution and geometry. Pitot tube measurements were performed to obtain the PSJAs' velocity profiles and to estimate the mechanical power delivered to the fluid.Optimal values of the inter-electrode distance and diameter have been found in order to maximize jet velocity, mechanical power or efficiency. Annular geometries are found to achieve the best performances.

Successively accelerated ionic wind with integrated dielectric-barrier-discharge plasma actuator for low-voltage operation

“…1b. This counter wind collides with the main flow and defects wind in the vertical direction to the dielectric surface when there is no gap between each actuator module, as in the case of so-called plasma synthetic jet actuators 22 . The generation of the counter ionic-wind due to the cross-talk phenomenon is undesirable in view of the multiplied acceleration of ionic wind by successive actuator modules.…”

Printed Circuit Boards: The Layers’ Functions for Electronic and Biomedical Engineering

“…This kind of device has been fabricated using Printed Circuit Boards because this decreases the manufacturing cost and weight. Two electrodes are required [ 164 , 165 , 166 , 167 , 168 , 169 ]: one of them for high-voltage and second one for the ground. These electrodes are fabricated on opposite sides of the PCB substrate, in which the insulation layer is FR4 and the dielectric breakdown voltage is determined by that material, about 50 kV.…”

Flow Control Methods and Their Applicability in Low-Reynolds-Number Centrifugal Compressors—A Review

“…The advantage of the plasma synthetic jet actuators is acceptable power consumption (order of 100 W) [66]. The experimental results of Neretti et al [68] indicated that the annular plasma synthetic jet actuator exhibits better performance than the linear version.…”