scholarly journals Selected structural elements of the wing to increase the lift force

2018 ◽  
Vol 19 (12) ◽  
pp. 764-767
Author(s):  
Ernest Gnapowski
Keyword(s):  
Flow Control ◽  
Lift Force ◽  
Active Flow Control ◽  
Plasma Actuator ◽  
Structural Elements ◽  
Dbd Plasma ◽  
Lifting Force ◽  
Active Flow

The article presents a currently used structural elements to increase the lift force. Presented mechanical and no-mechanical construction elements that increase the lifting force. The author's attention to the new direction of flow control using a DBD plasma actuator. This is a new direction of active flow control.

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.

Highly responsive multi-flow pattern generation by multi-electrode plasma actuator using a single power supply

2021 ◽  
Author(s):  
Kosuke Sugimoto ◽  
Satoshi Ogata
Keyword(s):  
Flow Control ◽  
Flow Pattern ◽  
Power Supply ◽  
Active Flow Control ◽  
Flow Patterns ◽  
Plasma Actuator ◽  
Pattern Generation ◽  
Switching Frequency ◽  
Wall Jet ◽  
Active Flow

Abstract A dielectric-barrier-discharge plasma actuator (DBD-PA) is an active flow-control device that uses ionic wind generated by electrohydrodynamic (EHD) forces. A DBD-PA controls fluid motion and offers quick response without the need for moving parts. Previous studies have proposed methods for generating various flow patterns with a DBD-PA for fluid control. This paper presents a method for generating multiple flow patterns using a multi-electrode DBD-PA that is driven by a single-channel high-voltage power supply with a relay circuit. In contrast, conventional methods of realizing multiple flow patterns involve the use of a multi-channel power supply. Hence, they have the disadvantage of requiring a complicated power supply system. The proposed method succeeded in realizing several induced-flow modes involving the generation of a directionally controllable wall jet, various sizes of vortices, and an upward jet by altering the switching frequency and switching ratio. In addition, our experimental results indicate that the proposed method can control the flow pattern with a significantly short response time. The direction of the wall jet can be switched within tens to hundreds of milliseconds. Therefore, the proposed method combines simplicity and versatility and is expected to facilitate the realization of multifunctional active flow control in various flow fields, such as flow turbulent boundary layer control, thermal diffusion control, gas mixing, and flame-stability enhancement.

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.

Experimental and Numerical Analysis of a Micro Plasma Actuator for Active Flow Control in Turbomachinery

2014 ◽  
Author(s):  
Maria Grazia De Giorgi ◽  
Elisa Pescini ◽  
Fedele Marra ◽  
Antonio Ficarella
Keyword(s):  
Flow Control ◽  
Active Flow Control ◽  
Plasma Actuator ◽  
The Body ◽  
Plasma Actuators ◽  
Compressor Cascade ◽  
Barrier Discharge Plasma ◽  
Induced Flow ◽  
The One ◽  
Active Flow

Nowadays several active flow control systems, particularly dielectric barrier discharge plasma actuators, appear to be effective for the control of flow stream separation and to improve performance of turbomachinery. However these applications require high actuation strength, higher than the one generated by conventional macro plasma actuators. Research is actually improving the design of plasma actuator in order to enhance the flow control capability and reduce the power consumption. In this contest, this work concerns the implementation of a micro plasma actuator for the active control in a compressor cascade. For this aim, firstly the micro actuator was developed and an experimental characterization of the flow induced by the device was done. The induced flow field was studied by means of Particle Image Velocimetry and Laser Doppler Velocimetry. The dissipated power was also evaluated. Experimental results were used to validate a multi-physics numerical model for the prediction of the body forces induced by the plasma actuator. Finally, the obtained body force field was used for modeling the separation control by means of the micro plasma actuator in a highly-loaded subsonic compressor stator.

Analysis of Innovative Plasma Actuator Geometries for Boundary Layer Control

2016 ◽  
Author(s):  
F. F. Rodrigues ◽  
J. C. Pascoa ◽  
M. Trancossi
Keyword(s):  
Boundary Layer ◽  
Power Consumption ◽  
Active Flow Control ◽  
Plasma Actuator ◽  
Synthetic Jet ◽  
Plasma Actuators ◽  
Boundary Layer Control ◽  
Dbd Plasma ◽  
Active Flow ◽  
Layer Control

Active flow control by plasma actuators is a topic of great interest by worldwide scientific community. These devices are mainly used for boundary layer control in order to improve the aerodynamic performance of aerial vehicles. Plasma actuators are simple devices that produces a wall bounded jet which allow to control the adjacent flow without moving mechanical parts. Recently, new geometries have been proposed by different authors in an attempt to improve the performance of these devices. In this work, some of these new configurations will be studied and compared considering its ability for boundary layer control applications. Dielectric Barrier Discharge (DBD) plasma actuator, Plasma Synthetic Jet (PSJ) actuator, Multiple Encapsulated Electrodes (MEE) plasma actuator and Curved plasma actuator (or 3D plasma actuator) will be experimentally studied in this work. Plasma actuators power consumption was measured by two different experimental methods. Results for power consumption and power losses of different plasma actuators geometries were presented and discussed.

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