Flow Control around a Rectangular Cylinder Using DBD Plasma Actuators

Abstract Dielectric Barrier Discharge (DBD) plasma actuators are simple devices with great potential for active flow control applications. Further, it has been recently proven their ability for applications in the area of heat transfer, such as film cooling of turbine blades or ice removal. The dielectric material used in the fabrication of these devices is essential in determining the device performance. However, the variety of dielectric materials studied in the literature is very limited and the majority of the authors only use Kapton, Teflon, Macor ceramic or poly(methyl methacrylate) (PMMA). Furthermore, several authors reported difficulties in the durability of the dielectric layer when the actuators operate at high voltage and frequency. Also, it has been reported that, after long operation time, the dielectric layer suffers degradation due to its exposure to plasma discharge, degradation that may lead to the failure of the device. Considering the need of durable and robust actuators, as well as the need of higher flow control efficiencies, it is highly important to develop new dielectric materials which may be used for plasma actuator fabrication. In this context, the present study reports on the experimental testing of dielectric materials which can be used for DBD plasma actuators fabrication. Plasma actuators fabricated of poly(vinylidene fluoride) (PVDF) and polystyrene (PS) have been fabricated and evaluated. Although these dielectric materials are not commonly used as dielectric layer of plasma actuators, their interesting electrical and dielectric properties and the possibility of being used as sensors, indicate their suitability as potential alternatives to the standard used materials. The plasma actuators produced with these nonstandard dielectric materials were analyzed in terms of electrical characteristics, generated flow velocity and mechanical efficiency, and the obtained results were compared with a standard actuator made of Kapton. An innovative calorimetric method was implemented in order to estimate the thermal power transferred by these devices to an adjacent flow. These results allowed to discuss the ability of these new dielectric materials not only for flow control applications but also for heat transfer applications.

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Dual-position excitation technique in flow control over an airfoil at low speeds

International Journal of Numerical Methods for Heat &amp Fluid Flow ◽

10.1108/hff-05-2018-0195 ◽

2018 ◽

Vol 30 (9) ◽

pp. 4141-4154

Author(s):

Abbas Ebrahimi ◽

Majid Hajipour ◽

Kamran Ghamkhar

Keyword(s):

Flow Control ◽

Shear Layer ◽

Control Method ◽

Lift Coefficient ◽

Shear Layers ◽

Control Flow ◽

Plasma Actuators ◽

Dbd Plasma ◽

Surface Shear ◽

Content Type

PurposeThe purpose of this paper is to control flow separation over a NACA 4415 airfoil by applying unsteady forces to the separated shear layers using dielectric barrier discharge (DBD) plasma actuators. This novel flow control method is studied under conditions which the airfoil angle of attack is 18°, and Reynolds number based on chord length is 5.5 × 105.Design/methodology/approachLarge eddy simulation of the turbulent flow is used to capture vortical structures through the airfoil wake. Power spectral density analysis of the baseline flow indicates dominant natural frequencies associated with “shear layer mode” and “wake mode.” The wake mode frequency is used simultaneously to excite separated shear layers at both the upper surface and the trailing edge of the airfoil (dual-position excitation), and it is also used singly to excite the upper surface shear layer (single-position excitation).FindingsBased on the results, actuations manipulate the shear layers instabilities and change the wake patterns considerably. It is revealed that in the single-position excitation case, the vortices shed from the upper surface shear layer are more coherent than the dual-position excitation case. The maximum value of lift coefficient and lift-to-drag ratio is achieved, respectively, by single-position excitation as well as dual-position excitation.Originality/valueThe paper contributes to the understanding and progress of DBD plasma actuators for flow control applications. Further, this research could be a beneficial solution for the promising design of advanced low speed flying vehicles.

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Dielectric Barrier Discharge (DBD) Plasma Actuators for Flow Control in Turbine Engines: Simulation of Flight Conditions in the Laboratory by Density Matching

International Journal of Turbo and Jet Engines ◽

10.1515/tjj-2018-0021 ◽

2019 ◽

Vol 36 (2) ◽

pp. 157-173

Author(s):

David E. Ashpis ◽

Douglas R. Thurman

Keyword(s):

Flow Control ◽

Dielectric Barrier Discharge ◽

Barrier Discharge ◽

Test Chamber ◽

Plasma Actuators ◽

Chamber Pressure ◽

Turbine Engines ◽

Dbd Plasma ◽

Dielectric Barrier ◽

Actuator Performance

Abstract We address requirements for laboratory testing of AC Dielectric Barrier Discharge (AC-DBD) plasma actuators for active flow control in aviation gas turbine engines. The actuator performance depends on the gas discharge properties, which, in turn, depend on the pressure and temperature. It is technically challenging to simultaneously set test-chamber pressure and temperature to the flight conditions. We propose that the AC-DBD actuator performance depends mainly on the gas density, when considering ambient conditions effects. This enables greatly simplified testing at room temperature with only chamber pressure needing to be set to match the density at flight conditions. For turbine engines, we first constructed generic models of four engine thrust-classes; 300-, 150-, 50-passenger, and military fighter, and then calculated the densities along the engine at sea-level takeoff and altitude cruise conditions. The range of chamber pressures that covers all potential applications was found to be from 3 to 1256 kPa (0.03 to 12.4 atm), depending on engine-class, flight altitude, and actuator placement in the engine. The engine models are non-proprietary and can be used as reference data for evaluation requirements of other actuator types and for other purposes. We also provided examples for air vehicles applications up to 19,812 m (65,000 ft).

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Flow Control on a Transport Truck Side Mirror Using Plasma Actuators

Journal of Fluids Engineering ◽

10.1115/1.4030724 ◽

2015 ◽

Vol 137 (11) ◽

Cited By ~ 13

Author(s):

Theodoros Michelis ◽

Marios Kotsonis

Keyword(s):

Flow Control ◽

Guide Vane ◽

Leading Edge ◽

Plasma Actuator ◽

Plasma Actuators ◽

Dbd Plasma ◽

Reference Case ◽

Image Velocimetry ◽

Wind Tunnel Study ◽

Edge Separation

A wind tunnel study is conducted toward hybrid flow control of a full scale transport truck side mirror at ReD=3.2×105. A slim guide vane is employed for redirecting high-momentum flow toward the mirror wake region. Leading edge separation from the guide vane is reduced or eliminated by means of an alternating current -dielectric barrier discharge (AC-DBD) plasma actuator. Particle image velocimetry (PIV) measurements are performed at a range of velocities from 15 to 25 m/s and from windward to leeward angles from -5deg to 5deg. Time-averaged velocity fields are obtained at the center of the mirror for three scenarios: (a) reference case lacking any control elements, (b) guide vane only, and (c) combination of the guide vane and the AC-DBD plasma actuator. The comparison of cases demonstrates that at 25 m/s windward conditions (-5deg) the guide vane is capable of recovering 17% momentum with respect to the reference case. No significant change is observed by activating the AC-DBD plasma actuator. In contrast, at leeward conditions (5deg), the guide vane results in a −20% momentum loss that is rectified to a 6% recovery with actuation. The above implies that for a truck with two mirrors, 23% of momentum may be recovered.

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Applications of String-type DBD Plasma Actuators for Flow Control in Turbomachineries

52nd Aerospace Sciences Meeting ◽

10.2514/6.2014-1126 ◽

2014 ◽

Cited By ~ 1

Author(s):

Takehiko Segawa ◽

Takayuki Matsunuma

Keyword(s):

Flow Control ◽

Plasma Actuators ◽

Dbd Plasma ◽

String Type

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Optimization and Evaluation of Multiple DBD Plasma Actuators Applied in the Tip Leakage Control for Turbine Cascade

Volume 2D: Turbomachinery ◽

10.1115/gt2019-90208 ◽

2019 ◽

Author(s):

Jianyang Yu ◽

Wenchun Bao ◽

Fu Chen ◽

Yanping Song ◽

Cong Wang

Keyword(s):

Flow Control ◽

Mass Flow ◽

Suction Side ◽

Plasma Actuator ◽

Plasma Actuators ◽

Leakage Flow ◽

Tip Leakage Flow ◽

Dbd Plasma ◽

Tip Leakage ◽

Leakage Control

Abstract The dielectric barrier discharge (DBD) plasma actuator, in which electrodes are asymmetric arranged, has already demonstrated its ability in flow control. In the present work, the configuration of multiple plasma actuators is placed at the suction side of the cascade top to realize the tip leakage control. However, massive configurations appear when the number of plasma actuators increases, resulting in the investigation of actuator configuration for tip leakage flow control becomes a challenge. The surrogate modelling approach provides a cheap and efficient method to investigate the effect of multiple plasma actuators on the tip leakage flow control. By constructing an approximation model, tip leakage mass flow rates of all configuration are obtained in the present work. What’s more, the flow structures in the tip clearance controlled by the plasma actuators are explained in the process of topological analysis. The results show that the tip leakage mass flow rate is decreasing with the number of active plasma actuators increasing. However, the decreasing would reach its limits in the process of adding plasma actuators. In the analysis of flow topology, single actuator would generate a small vortex at the suction side to cause an obstacle in the tip leakage flow. While the continuous arrangements of plasma actuator is beneficial to generate an induced vortex to diminish the tip leakage flow.

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Aerodynamic Flow Separation Control of Bridge Deck Sections Using Plasma Actuators

Volume 4: Fluid-Structure Interaction ◽

10.1115/pvp2015-45140 ◽

2015 ◽

Author(s):

Kazutoshi Matsuda ◽

Kusuo Kato

Keyword(s):

Flow Control ◽

Bridge Deck ◽

Surface Flow ◽

Bridge Girders ◽

Plasma Actuators ◽

Separation Control ◽

Wind Tunnel Experiments ◽

Dbd Plasma ◽

New Approach ◽

Flow Separation Control

In order to suppress wind-induced vibrations of bridge girders, two general methods are applied: aerodynamic and mechanical countermeasures. In this study, a new approach to suppress wind-induced vibrations, “a dielectric barrier discharge (DBD) plasma actuator”, was investigated through wind tunnel experiments to determine its potential as a device for flow control around bridge deck sections. This approach is already in use in other fields, such as in the fluid dynamics flow control for separation control in wing surface flow. In this study, it was found that there is a possibility that DBD plasma actuators could be used in the future as the devices for suppressing wind-induced vibrations of bridge girders.

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