Effect of the charge surface distribution on the flow field induced by a dielectric barrier discharge actuator

Abstract

The Electro-Hydro-Dynamics (EHD) interaction induced by a surface dielectric barrier discharge in the aerodynamic boundary layer at one atmosphere still air has been investigated. Three different geometrical configurations of the actuator have been utilized. In the first configuration, an electrode pair separated by a 2 mm dielectric sheet has been used. The second and the third configurations have been obtained by adding a third electrode on the upper side of the dielectric surface. This electrode has been placed downstream of the upper electrode and has been connected to ground or has been left floating. Three different dielectric materials have been utilized. The high voltage upper electrode was fed by an a.c. electric tension. Measurements of the dielectric surface potential generated by the charge deposition have been done. The discharge has been switched off after positive and negative phases of the plasma current (the current phase was characterized by a positive or a negative value, respectively). The measurements have been carried out after both phases. The charge distribution strongly depended on the switching off phase and was heavily affected by the geometrical configuration. A remarkable decrease of the charge deposited on the dielectric surface has been detected when the third electrode was connected to ground. Velocity profiles were obtained by using a Pitot probe. They showed that the presence of the third electrode limits the fluid dynamics performance of the actuator. A relation between the charge surface distribution and the EHD interaction phenomenon has been found. Imaging of the plasma has been done to evaluate the discharge structure and the extension of the plasma in the configurations investigated.

Geometry optimization of linear and annular plasma synthetic jet actuators

“…4) and electrode diameters in the circular case (D in Fig. 4) of 10,14,18,22,26,30,34,38,42,46, and 50 mm.…”

“…This ionic wind can significantly modify the properties of the boundary layer developing on body surfaces [3]. Interest for this phenomenon is growing in aeronautics, astronautics [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20], and for turbine blade applications [21][22][23][24][25]. Plasma aerodynamic actuators are more attractive than other active actuator technologies because they feature high dynamic responses due to the absence of moving parts and low weight, they are easy to build, backward compatible with existing aerodynamic surfaces, and generate negligible aerodynamics interferences when not in use.…”

Surface potential distribution and airflow performance of different air-exposed electrode plasma actuators at different alternating current/direct current voltages

“…[20][21][22] The appearance of surface potential far from the discharge plasma regime is probably formed by the surface migration of the accumulated charges. 20,24,25 The axial surface potential distributions, with the V pp ¼ 12 kV AC voltage superimposed on the DC bias of þ1 kV, þ3 kV, þ5 kV, þ7 kV and À1 kV, À3 kV, À5 kV, À7 kV, are shown in Fig. 9.…”

“…The result showed that the surface potential depended primarily on the bias voltage. Cristofolini et al 24,25 also measured the surface potential distribution for different discharge periods and different dielectric materials. However, the effects of plasma actuators with different air-exposed electrodes on the surface potential distribution and surface potential (especially after a) rchsh@dlut.edu.cn 1070-664X/2015/22(4)/043518/8/$30.00 V C 2015 AIP Publishing LLC 22, 043518-1 adding bias voltage) on the airflow field have not yet been studied carefully.…”

Geometry Effects of SDBD Actuator on Atmospheric-Pressure Discharge Plasma Airflow Acceleration

“…Thus, the surface potential is formed. The appearance of surface potential in the far downstream of the plasma regime can be attributed to the migration of the accumulated charges along the quartz glass plate surface [37], [38].…”