Influence of Exposed Electrode Thickness on Plasma Actuators Performance for Coupled Deicing and Flow Control Applications

2021 ◽  
Author(s):  
F. F. Rodrigues ◽  
M. Abdollahzadeh ◽  
J. Pascoa ◽  
L. Pires

Abstract Dielectric Barrier Discharge (DBD) plasma actuators are a popular topic of research within the active flow control field. Recently, these devices have gained interest for deicing and ice prevention applications and it has been proved they allow to perform simultaneously deicing and flow control. Studies have shown that the exposed electrode plays an important role on the surface temperature field of the plasma actuator. Thus, in the current study, by the first time, we investigate the influence of the exposed electrode thickness on the induced velocity flow field and surface temperature field. Three plasma actuators with different dielectric thicknesses (0.3 mm, 0.6 mm and 1.02 mm) were mounted with a thick exposed electrode (thickness of 0.8 mm). These three actuators with thick exposed electrode were experimentally studied and compared against other three plasma actuators with same dielectric thickness but with a thin exposed electrode (thickness of 80 μm). The DBD actuators were experimentally studied considering their electrical, mechanical and thermal behavior. The results are presented and discussed in order to understand the influence of the exposed electrode thickness on the mechanical and thermal plasma actuator performances.

2021 ◽  
Author(s):  
F. F. Rodrigues ◽  
J. Nunes-Pereira ◽  
M. Abdollahzadeh ◽  
J. Pascoa ◽  
S. Lanceros-Mendez

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.


2015 ◽  
Vol 137 (11) ◽  
Author(s):  
Theodoros Michelis ◽  
Marios Kotsonis

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.


Author(s):  
Jianyang Yu ◽  
Wenchun Bao ◽  
Fu Chen ◽  
Yanping Song ◽  
Cong Wang

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.


Author(s):  
David E. Ashpis ◽  
Douglas R. Thurman

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.


Author(s):  
Maria Grazia De Giorgi ◽  
Elisa Pescini ◽  
Fedele Marra ◽  
Antonio Ficarella

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.


Author(s):  
F. F. Rodrigues ◽  
M. Abdollahzadeh ◽  
J. Pascoa

Abstract An experimental investigation was conducted in order to understand the ability of plasma actuators to operate in three different modes: flow control, ice formation detection and ice accumulation prevention. When plasma actuators are operated with voltage levels, above the breakdown voltage, a plasma discharge surface is generated and with that, an ionic wind is produced. By using this phenomena, plasma actuators may be used to manipulate flow fields and control adjacent flows to the surface in which they are applied. However, a big part of the power applied to the device is dissipated as heat. Due to heat dissipation, the actuator surface temperature rises and the adjacent air is heated. Considering this, actuators may operate as ice prevention devices by heating the surface where they are applied and preventing the ice formation and accumulation. On the other hand, plasma actuators present a behavior similar to a capacitor and they may operate as a capacitive sensor. In the presence of water or ice on the top of the surface, the electric field changes and with that, several plasma actuator electrical features change as well. By monitoring that changes, the presence of water or ice on the top of the surface can be detected and the plasma actuator may be used as an ice sensor device. Therefore, in the present study a plasma actuator was experimentally tested operating in these three different operation modes and its feasibility to perform these different tasks is shown.


Author(s):  
F. F. Rodrigues ◽  
J. C. Pascoa ◽  
M. Trancossi

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.


Author(s):  
Hongyu Jin ◽  
Takashi Ono ◽  
Motoaki Kimura

Dielectric barrier discharge (DBD) plasma actuators have been investigated by many researchers as flow-control devices. In the present study, we attempt to apply such actuators to a jet flow. In order to achieve enhanced mixing in a jet flow, we focused on the voltage and the frequency of the plasma actuator to examine their effect on the velocity and turbulence of the jet flow. This time, we examined how the induced flow by the plasma actuator electrode dimensions occurred. It was expected that higher velocity would have a larger effect on the jet flow in last year. In this study, we measured the flow velocity for different voltages and frequencies, and determined the most effective conditions for generating the induced flow. We apply that DBD plasma actuators to enhance turbulent intensity and jet flow’s diffusion.


2020 ◽  
Author(s):  
Miguel André Barbosa Moreira ◽  
Frederico Miguel Freire Rodrigues ◽  
José Carlos Páscoa Marques

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


Sign in / Sign up

Export Citation Format

Share Document