Multidimensional Collisional Dielectric Barrier Discharge for Flow Separation Control at Atmospheric Pressures

The surface dielectric barrier discharge plasma actuator driven by nanosecond pulses is recognized as an effective fluid actuator for flow separation control. The operation condition of nanosecond dielectric barrier discharge actuators for separated flow control still requires further study, particularly prioritizing the improvement of the effectiveness and reducing energy consumption in flow separation control implementation. In this study, experiments are conducted using a two-dimensional NASA SC(2)-0712 airfoil in a wind tunnel with a Reynolds number of 0.5 × 106 (25 m/s). The pressure measurement experiments show that the location of actuators affects the efficiency of separation control. Particle image velocimetry results indicate that the most efficient location of the actuator is upstream of the separation point and near the original point of the separated shear layer. Meanwhile, the particle image velocimetry results show the vorticity attaches to the airfoil wall after discharge, which suggests that the reattachment is due to the generation of large-scale vortices. These present structures result in the mixing of the shear layer with the main flow thereby delaying separation and reattaching a separated flow. This study shows the most efficient location related to the separation point. Furthermore, it indicates the reattachment of flow is attributed to the motion of vortexes coherent structure.

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Flow Separation Control of Nacelle in Crosswind by Microsecond Pulsed Surface Dielectric Barrier Discharge Plasma Actuator

Flow Turbulence and Combustion ◽

10.1007/s10494-021-00247-0 ◽

2021 ◽

Author(s):

Yuhao Jia ◽

Hua Liang ◽

Qikun He ◽

Zhi Su ◽

Guoxing Song

Keyword(s):

Flow Separation ◽

Discharge Plasma ◽

Barrier Discharge ◽

Plasma Actuator ◽

Separation Control ◽

Dielectric Barrier Discharge Plasma ◽

Dielectric Barrier ◽

Flow Separation Control ◽

Barrier Discharge Plasma ◽

Surface Dielectric Barrier Discharge

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Flow separation control behind a cylindrical bump using dielectric-barrier-discharge vortex generator plasma actuators

Journal of Fluid Mechanics ◽

10.1017/jfm.2017.773 ◽

2017 ◽

Vol 835 ◽

pp. 852-879 ◽

Cited By ~ 8

Author(s):

Julie A. Vernet ◽

Ramis Örlü ◽

P. Henrik Alfredsson

Keyword(s):

Dielectric Barrier Discharge ◽

Flow Separation ◽

Large Scale ◽

Barrier Discharge ◽

Control Flow ◽

Wake Flow ◽

Plasma Actuators ◽

Streamwise Vortices ◽

Dielectric Barrier ◽

Flow Separation Control

Dielectric-barrier-discharge plasma actuators are arranged to produce counter-rotating streamwise vortices to control flow separation on a cylindrical bump on a flat plate that is approached by a turbulent boundary layer. The control was tested for different free-stream velocities and actuation driving voltages. The recirculation area downstream of the bump was reduced by the actuation for velocities up to $15~\text{m}~\text{s}^{-1}$ at the highest voltage achievable of the present set-up. However, the flow shows a bi-modality, the nominal two-dimensional wake flow is shown to consist of large-scale streamwise vortices, which are energised by the actuation until a phenomenon of lock-on of these vortices occurs at sufficiently high driving voltages. The wavelength of the actuation is half that of the large-scale vortices. The lock-on shifts sometimes, i.e. the large streamwise vortices centre switch spanwise location, explaining the bi-modality in the flow. The details of the bi-modality are further investigated by conditional averaging and proper orthogonal decomposition.

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