Three-dimensional effects of curved plasma actuators in quiescent air

Abstract

This paper presents results on a new class of curved plasma actuators for the inducement of three-dimensional vortical structures. The nature of the fluid flow inducement on a flat plate, in quiescent conditions, due to four different shapes of dielectric barrier discharge (DBD) plasma actuators is numerically investigated. The three-dimensional plasma kinetic equations are solved using our in-house, finite element based, multiscale ionized gas (MIG) flow code. Numerical results show electron temperature and three dimensional plasma force vectors for four shapes, which include linear, triangular, serpentine, and square actuators. Three-dimensional effects such as pinching and spreading the neighboring fluid are observed for serpentine and square actuators. The mechanisms of vorticity generation for DBD actuators are discussed. Also the influence of geometric wavelength (k) and amplitude (K) of the serpentine and square actuators on vectored thrust inducement is predicted. This results in these actuators producing significantly better flow mixing downstream as compared to the standard linear actuator. Increasing the wavelengths of serpentine and square actuators in the spanwise direction is shown to enhance the pinching effect giving a much higher vertical velocity. On the contrary, changing the amplitude of the curved actuator varies the streamwise velocity significantly influencing the near wall jet. Experimental data for a serpentine actuator are also reported for validation purpose. V

Compared ionic wind measurements on multi-tip corona and DBD plasma actuators

“…Also in the DBD actuators the tips are regions of high ionization, but the discharge is generated along the whole contour of the active electrode, and the gas velocity is locally normal to the contour line. This gives rise to a gas stream with a three-dimensional structure, well-known in literature for electrodes of periodic shape [7,9]. In particular, regions between adjacent tips create a vertical component directed away from the wall, whereas in the regions behind tips the flow moves toward the wall.…”

“…Sharp tips increase ionic wind and thrust [5,6], and in general all these shapes may induce transverse velocity components that lead to three-dimensional flows in the near field and finally to the creation of streamwise vortex structures [3,7], useful for the boundary layer control when the actuator interacts with an external stream.…”

The multichannel discharge plasma synthetic jet actuator

“…One actuator features multi-electrodes in serial arrangement [7] , while there is also DBD actuator with three-electrode [8] . Three-dimensional vortical structure can also be produced through DBD actuators through realignment of the electrodes in to shapes of triangle, serpentine and square [9] .…”

Numerical design and analysis of a multi-DBD actuator configuration for the experimental testing of ACHEON nozzle model

“…It is only related to the surface jet created by the plasma actuator (here with 2.4 m/s speed). ( ) ( ) Besides the standard configuration of the actuator that was shown with single and multiple DBDs, plasma actuators can be used in several different configurations [23,[34][35][36][37]. Here, using 2D modeling we only consider two of these configurations.…”