Control of unsteady flow separation over a circular cylinder using dielectric-barrier-discharge surface plasma

2009 ◽  
Vol 21 (9) ◽  
pp. 094106 ◽  
Author(s):  
Timothy N. Jukes ◽  
Kwing-So Choi
Keyword(s):  
Circular Cylinder ◽  
Unsteady Flow ◽  
Dielectric Barrier Discharge ◽  
Flow Separation ◽  
Barrier Discharge ◽  
Surface Plasma ◽  
Dielectric Barrier

Lift Augmentation Based on Flap Deflection With Dielectric Barrier Discharge Plasma Flow Control Over Multi-Element Airfoils

2015 ◽  
Vol 138 (3) ◽  
Author(s):  
Leilei Yang ◽  
Jiang Li ◽  
Jinsheng Cai ◽  
Guangqiu Wang ◽  
Zhengke Zhang
Keyword(s):  
Flow Control ◽  
Dielectric Barrier Discharge ◽  
Plasma Flow ◽  
Flow Separation ◽  
Barrier Discharge ◽  
Force Model ◽  
Freestream Velocity ◽  
Dielectric Barrier ◽  
Plasma Flow Control ◽  
Flap Deflection

The effect of the lift augmentation of multi-element airfoils with increased flap deflection and dielectric barrier discharge (DBD) plasma flow control on the flap at several angles of attack (AOAs) is investigated numerically and experimentally. A phenomenological body force model is employed to simulate the DBD actuators at Re = 1.03 × 106. The simulation results show that the atmospheric plasma generated by the DBD actuators completely suppresses the flow separation over the flap at several AOAs, and consequently, the lift augmentation of a multi-element airfoil can be achieved over the entire prestall AOA range. A corresponding flow control experiment on a multi-element airfoil performed in a low-speed wind tunnel at a freestream velocity of 30 m/s is presented; in this experiment, particle image velocimetry (PIV) was employed for flow visualization over the upper surface of the flap. The PIV results demonstrate that the flow separation on the flap is suppressed completely by the same DBD actuators used in the simulation.

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

2017 ◽  
Vol 835 ◽  
pp. 852-879 ◽  
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.

Sign in / Sign up

Export Citation Format

Share Document