Characterization of Tollmien-Schlichting Wave Damping by DBD Plasma Actuators Using Phase-Locked PIV

2012 ◽  
Author(s):  
Alexander Duchmann ◽  
Armin Kurz ◽  
Alexander Widmann ◽  
Sven Grundmann ◽  
Cameron Tropea
Keyword(s):  
Plasma Actuators ◽  
Dbd Plasma ◽  
Wave Damping ◽  
Tollmien Schlichting

Test Conditions for Performance Characterization of Dielectric Barrier Discharge (DBD) Plasma Actuators for Active Flow Control in Jet Engines

2011 ◽  
Author(s):  
David E. Ashpis ◽  
Douglas R. Thurman
Keyword(s):  
Flow Control ◽  
Dielectric Barrier Discharge ◽  
Barrier Discharge ◽  
Active Flow Control ◽  
Plasma Actuators ◽  
Dbd Plasma ◽  
Dielectric Barrier ◽  
Jet Engine ◽  
Active Flow

Dielectric Barrier Discharge (DBD) plasma actuators for active flow control in the jet engine need to be tested in the laboratory to characterize their performance at flight operating conditions. DBD plasma actuators generate a wall-jet electronically by creating weakly ionized plasma, therefore their performance is affected by gas discharge properties, which in turn depend on the pressure and temperature at the actuator placement location. Characterization of actuators is initially performed in a laboratory chamber without external flow. It is usually impractical to simultaneously set engine pressures and temperatures in a chamber, and a simplified approach is desired. It is assumed that the plasma discharge depends only on the gas density. Other temperature effects are assumed to be negligible. Therefore, tests can be performed at room temperature with chamber pressure set to yield the same density as in engine operating flight conditions. Engine data was obtained from four generic engine models; 300-, 150-, and 50-Passenger (PAX) aircraft engines, and a military jet-fighter engine. The static and total pressure, temperature, and density distributions along the engine were calculated for sea-level takeoff and altitude cruise, and the chamber pressures needed to test the actuators were calculated. The results show that testing has to be performed over a wide range of pressures from 12.4 to 0.03 atm, depending on the application. For example, if a DBD plasma actuator is to be placed at the compressor exit of a 300 PAX engine, it has to be tested at 12.4 atm for takeoff, and 6 atm for cruise conditions. If it is to be placed at the low-pressure turbine, it has to be tested at 0.5 and 0.2 atm, respectively. These results have implications for the feasibility and design of DBD plasma actuators for jet engine flow control applications. In addition, the distributions of unit Reynolds number, Mach number, and velocity along the engine are provided. The engine models are non-proprietary and this information can be used for evaluation of other types of actuators and for other purposes.

Tollmien--Schlichting wave damping by a streamwise oscillating Lorentz force

2008 ◽  
Vol 44 (3) ◽  
pp. 205-222 ◽  
Author(s):  
T. Albrecht ◽  
H. Metzkes ◽  
R. Grundmann ◽  
G. Mutschke ◽  
G. Gerbeth
Keyword(s):  
Lorentz Force ◽  
Wave Damping ◽  
Tollmien Schlichting

HF DBD plasma actuators for reduction of cylinder noise in flow

2017 ◽  
Vol 50 (47) ◽  
pp. 475204 ◽  
Author(s):  
V F Kopiev ◽  
P N Kazansky ◽  
V A Kopiev ◽  
I A Moralev ◽  
M Yu Zaytsev
Keyword(s):  
Plasma Actuators ◽  
Dbd Plasma

In-Flight Transition Delay with DBD Plasma Actuators

2013 ◽  
Author(s):  
Alexander Duchmann ◽  
Bernhard Simon ◽  
Philip Magin ◽  
Cameron Tropea ◽  
Sven Grundmann
Keyword(s):  
Plasma Actuators ◽  
Dbd Plasma ◽  
Transition Delay

Experimental Comparison of DBD Plasma Actuators for Low Reynolds Number Separation Control

2012 ◽  
Vol 135 (1) ◽  
Author(s):  
Christopher R. Marks ◽  
Rolf Sondergaard ◽  
Mitch Wolff ◽  
Rich Anthony
Keyword(s):  
Reynolds Number ◽  
Low Reynolds Number ◽  
Turbine Blades ◽  
Plasma Actuators ◽  
Experimental Comparison ◽  
Separation Control ◽  
Suction Surface ◽  
Dbd Plasma ◽  
Low Reynolds ◽  
Low Reynolds Number Airfoil

This paper presents experimental work comparing several Dielectric Barrier Discharge (DBD) plasma actuator configurations for low Reynolds number separation control. Actuators studied here are being investigated for use in a closed loop separation control system. The plasma actuators were fabricated in the U.S. Air Force Research Laboratory Propulsion Directorate’s thin film laboratory and applied to a low Reynolds number airfoil that exhibits similar suction surface behavior to those observed on Low Pressure (LP) Turbine blades. In addition to typical asymmetric arrangements producing downstream jets, one electrode configurations was designed to produce an array of off axis jets, and one produced a spanwise array of linear vertical jets in order to generate vorticity and improved boundary layer to freestream mixing. The actuators were installed on an airfoil and their performance compared by flow visualization, surface stress sensitive film (S3F), and drag measurements. The experimental data provides a clear picture of the potential utility of each design. Experiments were carried out at four Reynolds numbers, 1.4 × 105, 1.0 × 105, 6.0 × 104, and 5.0 × 104 at a-1.5 deg angle of attack. Data was taken at the AFRL Propulsion Directorate’s Low Speed Wind Tunnel (LSWT) facility.

Comparative Evaluation of Dielectric Materials for Plasma Actuators Active Flow Control and Heat Transfer Applications

2021 ◽  
Author(s):  
F. F. Rodrigues ◽  
J. Nunes-Pereira ◽  
M. Abdollahzadeh ◽  
J. Pascoa ◽  
S. Lanceros-Mendez
Keyword(s):  
Heat Transfer ◽  
Flow Control ◽  
Dielectric Layer ◽  
Active Flow Control ◽  
Thermal Power ◽  
Dielectric Materials ◽  
Plasma Actuators ◽  
Dbd Plasma ◽  
Control Applications ◽  
Active Flow

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.

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

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.

Sign in / Sign up

Export Citation Format

Share Document