Experimental Analysis of Alternative Dielectric Materials for DBD Plasma Actuators

2018 ◽  
Author(s):  
F. F. Rodrigues ◽  
J. C. Pascoa ◽  
M. Trancossi
Keyword(s):  
Dielectric Material ◽  
Experimental Testing ◽  
Low Cost ◽  
Active Flow Control ◽  
Dielectric Strength ◽  
Dielectric Materials ◽  
Plasma Actuators ◽  
Poly Lactic Acid ◽  
Dbd Plasma ◽  
Advantages And Disadvantages

Dielectric Barrier Discharge plasma actuators are simple devices with great potential for active flow control applications. They have very interesting features which have made them a topic of interest for many researchers, for instance they present very low mass, fast response time, low cost, easy implementation and they are fully electronic with no moving parts. The dielectric material used in the construction of these devices present an important role in their performance. The variety of dielectrics studied in the literature is very restrict and the majority of the authors make use of Kapton, Teflon, Macor ceramic or PMMA. Furthermore, several authors reported difficulties in the durability of the dielectric layer when actuators operate at high levels of voltage and frequency. Considering this background, the present study focus on the experimental testing of alternative dielectric materials which can be used for DBD plasma actuators fabrication. Considering this, plasma actuators with dielectric layers made of Poly-Isobutylene rubber, Poly-Lactic acid and Acetoxy Silicon were experimentally tested. Although these dielectric materials are not commonly used in plasma actuators, their values of dielectric strength and dielectric permittivity indicate they can be good solutions. The plasma actuators facbricated with these alternative dielectric materials were experimentally analysed in terms of electrical characteristics and induced flow velocity, and the obtained results were compared with an actuator made of Kapton which is, currently, the most common dielectric material for plasma actuators. The effectiveness of the actuators was estimated and the advantages and disadvantages of the use of each dielectric material were discussed.

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.

scholarly journals Experimental Study of Dielectric Barrier Discharge Plasma Actuators for Active Flow Control

2020 ◽  
Author(s):  
Miguel André Barbosa Moreira ◽  
Frederico Miguel Freire Rodrigues ◽  
José Carlos Páscoa Marques
Keyword(s):  
Flow Control ◽  
Dielectric Barrier Discharge ◽  
Barrier Discharge ◽  
Active Flow Control ◽  
Dielectric Materials ◽  
Plasma Actuators ◽  
Dbd Plasma ◽  
Dielectric Barrier ◽  
Suitable Material ◽  
Active Flow

The objective of this study is to compare the effect of varying the material used as dielectric layer on the properties of the plasma actuators themselves. The experiments have shown that actuators with a PIB dielectric have a lower power consumption, can achieve higher velocities and have a better mechanical efficiency, but are more prone to failure due to breakdown of the dielectric. We verified that PIB rubber is a suitable material for DBD plasma actuators fabrication presenting several interesting features. Keywords: Active flow control, Plasma actuators, Dielectric barrier discharge, Dielectric materials

Experimental Thermal Characterization of DBD Plasma Actuators

2017 ◽  
Author(s):  
F. F. Rodrigues ◽  
J. C. Pascoa ◽  
M. Trancossi
Keyword(s):  
Electric Fields ◽  
Thermal Behaviour ◽  
Film Cooling ◽  
Active Flow Control ◽  
Thermal Characteristics ◽  
Dielectric Materials ◽  
Fast Response ◽  
Plasma Actuators ◽  
Total Power ◽  
Dbd Plasma

DBD plasma actuators have several applications within the field of active flow control. Separation control, wake control, aircraft noise reduction, modification of velocity fluctuations or boundary layer control are just some examples of their applications. They present several attractive features such as, their simple construction, very low mass, fast response, low power consumption and robustness. Besides their aerodynamic applications, these devices have also possible applications within the field of heat transfer, for example film cooling applications. However, due to the extremely high electric fields in the plasma region and consequent impossibility of applying intrusive techniques, there is a relative lack of information about DBDs thermal characteristics. In an attempt to contradict this scenario, this work describes the thermal behaviour of DBD plasma actuators. The total power consumed, the fraction of power that is dissipated as heat energy and the dielectric temperature variation due to the plasma operation are some parameters with great interest in any plasma actuator applications. Thus, these parameters were quantified and the results were presented and discussed. Infra-red thermography measurements were performed in order to obtain the temperature distribution of the dielectric layer. During this work we analysed DBD plasma actuators with different dielectric thicknesses and also with different dielectric materials, whose thermal behaviour was not reported in the literature yet. Conclusions were taken in order to extend the fundamental knowledge on the thermal aspects of the DBD plasma actuators.

scholarly journals High-K dielectric sulfur-selenium alloys

2019 ◽  
Vol 5 (5) ◽  
pp. eaau9785 ◽  
Author(s):  
Sandhya Susarla ◽  
Thierry Tsafack ◽  
Peter Samora Owuor ◽  
Anand B. Puthirath ◽  
Jordan A. Hachtel ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Metal Oxides ◽  
High Dielectric Constant ◽  
Dielectric Material ◽  
Dielectric Strength ◽  
Dielectric Materials ◽  
High K ◽  
Device Applications ◽  
High K Dielectric ◽  
High Dielectric

Upcoming advancements in flexible technology require mechanically compliant dielectric materials. Current dielectrics have either high dielectric constant, K (e.g., metal oxides) or good flexibility (e.g., polymers). Here, we achieve a golden mean of these properties and obtain a lightweight, viscoelastic, high-K dielectric material by combining two nonpolar, brittle constituents, namely, sulfur (S) and selenium (Se). This S-Se alloy retains polymer-like mechanical flexibility along with a dielectric strength (40 kV/mm) and a high dielectric constant (K = 74 at 1 MHz) similar to those of established metal oxides. Our theoretical model suggests that the principal reason is the strong dipole moment generated due to the unique structural orientation between S and Se atoms. The S-Se alloys can bridge the chasm between mechanically soft and high-K dielectric materials toward several flexible device applications.

Reduction of Fan and Compressor Wake Defect Using Plasma Actuation for Tonal Noise Reduction

2010 ◽  
Vol 133 (1) ◽  
Author(s):  
Sébastien Lemire ◽  
Huu Duc Vo
Keyword(s):  
Body Force ◽  
Dielectric Material ◽  
Computational Study ◽  
Active Flow Control ◽  
Control Device ◽  
Plasma Actuators ◽  
Simple Type ◽  
Tonal Noise ◽  
Trailing Edge ◽  
Compressor Rotor

This paper proposes a new technique to reduce the noise generated by rotor-stator interaction (tonal noise) in fans and compressors. The method involves the use of single dielectric barrier discharge (plasma) actuators near the blade trailing edge to reduce blade wakes. Plasma actuators are a new and simple type of active flow control device consisting of two parallel and offset electrodes separated by a layer of dielectric material. The application of a high ac voltage at high frequency to the electrodes generates a body force on the flow in the vicinity of the electrodes to inject momentum without mass addition. A preliminary assessment of the proposed concept is performed with a computational study on modern low-speed compressor rotor geometry. A plasma actuator model is implemented in an established turbomachinery CFD code. Simulations are carried out to evaluate the effect of the actuator strength, location, and actuation method (continuous versus pulsed) on the rotor wake. Results show that plasma actuators operated in continuous mode near the trailing edge can significantly influence the wake of the rotor with relatively little power consumption. The effectiveness of the actuation is proportional to actuator strength (induced body force). The exact position of the actuator in the trailing edge region has little effect on the effectiveness of the actuation. The results from simulations with pulsed actuation show very low time-averaged influence on the wake and are not fully conclusive, due possibly to the frequencies simulated and the limitations of the RANS CFD tool.

scholarly journals Video-Rate Identification of High-Capacity Low-Cost Tags in the Terahertz Domain

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3692
Author(s):  
Florent Bonnefoy ◽  
Maxime Bernier ◽  
Etienne Perret ◽  
Nicolas Barbot ◽  
Romain Siragusa ◽  
...  
Keyword(s):  
Radio Frequency Identification ◽  
Dielectric Material ◽  
Low Cost ◽  
High Capacity ◽  
Wide Band ◽  
Dielectric Materials ◽  
Surface Pattern ◽  
Rfid Tags ◽  
Performance Limits ◽  
Terahertz Time Domain Spectroscopy

In this article, we report on video-rate identification of very low-cost tags in the terahertz (THz) domain. Contrary to barcodes, Radio Frequency Identification (RFID) tags, or even chipless RFID tags, operate in the Ultra-Wide Band (UWB). These THz labels are not based on a planar surface pattern but are instead embedded, thus hidden, in the volume of the product to identify. The tag is entirely made of dielectric materials and is based on a 1D photonic bandgap structure, made of a quasi-periodic stack of two different polyethylene-based materials presenting different refractive indices. The thickness of each layer is of the order of the THz wavelength, leading to an overall tag thickness in the millimetre range. More particularly, we show in this article that the binary information coded within these tags can be rapidly and reliably identified using a commercial terahertz Time Domain Spectroscopy (THz-TDS) system as a reader. More precisely, a bit error rate smaller than 1% is experimentally reached for a reading duration as short as a few tens of milliseconds on an 8 bits (~40 bits/cm2) THID tag. The performance limits of such a tag structure are explored in terms of both dielectric material properties (losses) and angular acceptance. Finally, realistic coding capacities of about 60 bits (~300 bits/cm2) can be envisaged with such tags.

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.

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.

Reduction of Fan and Compressor Wake Defect Using Plasma Actuation for Tonal Noise Reduction

2008 ◽  
Author(s):  
Se´bastien Lemire ◽  
Huu Duc Vo
Keyword(s):  
Body Force ◽  
Dielectric Material ◽  
Computational Study ◽  
Active Flow Control ◽  
Control Device ◽  
Plasma Actuators ◽  
Simple Type ◽  
Tonal Noise ◽  
Trailing Edge ◽  
Compressor Rotor

This paper proposes a new technique to reduce the noise generated by rotor-stator interaction (tonal noise) in fans and compressors. The method involves the use of single dielectric barrier discharge (plasma) actuators near the blade trailing edge to reduce blade wakes. Plasma actuators are a new and simple type of active flow control device consisting of two parallel and offset electrodes separated by a layer of dielectric material. The application of a high AC voltage at high frequency to the electrodes generates a body force on the flow in the vicinity of the electrodes to inject momentum without mass addition. A preliminary assessment of the proposed concept is performed with a computational study on a modern low-speed compressor rotor geometry. A plasma actuator model is implemented in an established turbomachinery CFD code. Simulations are carried out to evaluate the effect of the actuator strength, location and actuation method (continuous versus pulsed) on the rotor wake. Results show that plasma actuators operated in continuous mode near the trailing edge can significantly influence the wake of the rotor with relatively little power consumption. The effectiveness of the actuation is proportional to actuator strength (induced body force). The exact position of the actuator in the trailing edge region has little effect on the effectiveness of the actuation. The results from simulations for pulsed actuation show very low time-averaged influence on the wake and are not fully conclusive, due possibly to the frequencies simulated and the limitations of the RANS CFD tool.

Cycloidal Rotor Propulsion System With Plasma Enhanced Aerodynamics

2014 ◽  
Author(s):  
Carlos M. Xisto ◽  
José C. Páscoa ◽  
Jakson A. Leger
Keyword(s):  
Barrier Discharge ◽  
Active Flow Control ◽  
Plasma Actuators ◽  
Dbd Plasma ◽  
Dielectric Barrier ◽  
Aerodynamic Efficiency ◽  
Rotating Blades ◽  
Numerical Tools ◽  
Active Flow ◽  
High Angles Of Attack

A cyclorotor consists of a set of blades rotating about an horizontal axis that is parallel to the blade span. The designation of cycloidal rotor is related to the cycloidal path described by the rotating blades during forward flight. In the following paper we study, trough the use of numerical tools, the PECyT (Plasma Enhanced Cycloidal Thruster) system as a way of improving the performance of classical cycloidal rotors. PECyT consists in the introduction of Dielectric Barrier Discharge (DBD) plasma actuators in the CR blades. Such system act as an active flow control that is able to delay the stall onset at high angles of attack, thus increasing the aerodynamic efficiency of each blade.

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