Plasma Actuators Optimization Using Stair Shaped Dielectric Layers

2019 ◽  
Author(s):  
F. F. Rodrigues ◽  
J. Pascoa Marques ◽  
M. Trancossi
Keyword(s):  
Flow Velocity ◽  
Dielectric Layer ◽  
Film Cooling ◽  
Turbine Blades ◽  
Plasma Discharge ◽  
Plasma Actuator ◽  
Plasma Actuators ◽  
Dielectric Thickness ◽  
New Device ◽  
Induced Flow

Abstract Plasma actuators are very simple devices which have been shown to be effective in a wide variety of applications, such as separation control, wake control, aircraft noise reduction, modification of velocity fluctuations and boundary layer control. More recently, it has been also proved their ability for applications within the heat transfer field, such as film cooling of turbine blades or ice accumulation prevention. These simple devices are inexpensive, present robustness, low weight and are fully electronic. Considering the importance of these devices, the improvement of their efficiency is a subject of great interest for worldwide scientific community. It is known that, by reducing the plasma actuator dielectric thickness, the induced flow velocity increases. However, it is also known that, thin plasma actuators present short lifetime and quick dielectric layer degradation. Till now, only actuators with constant dielectric thickness have been studied. In the present work, a new concept of plasma actuator is studied: The stair shaped dielectric barrier discharge plasma actuator. This new device present a dielectric layer which provides a decrease of the dielectric thickness along the covered electrode width. This lead to an extended plasma discharge and an increase of the induced flow velocity and efficiency. In addition, the plasma discharge is weakened on the onset of plasma formation which prevents the quick degradation of the dielectric layer and leads to an increased actuator lifetime.

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.

Plasma Actuators for Boundary Layer Control of Next Generation Nozzles

2015 ◽  
Author(s):  
F. Rodrigues ◽  
José C. Páscoa ◽  
F. Dias ◽  
M. Abdollahzadeh
Keyword(s):  
Boundary Layer ◽  
Dielectric Layer ◽  
Jet Flow ◽  
Plasma Actuator ◽  
Plasma Actuators ◽  
Boundary Layer Control ◽  
Next Generation ◽  
Dbd Plasma ◽  
Ionized Air ◽  
Layer Control

DBD plasma actuators are simple devices comprising two electrodes separated by a dielectric layer. One of the electrodes is covered by the dielectric layer and is completely insulated from the other one, which is exposed to the atmosphere in the top of the dielectric layer. The DBD plasma actuator operates by applying to the two electrodes an high voltage at high frequency from a power supply. When the amplitude of the applied voltage is large enough, in the exposed electrode, an ionization of the air (plasma) occurs over the dielectric surface which, in the presence of the electric field gradient, produces a body force on the ionized air particles. This induces a flow that draws ionized air along the surface of the actuator and it accelerates this neutral air towards downstream, in a direction tangential to the dielectric. Herein we will present this next generation plasma actuator for boundary layer control, which is demonstrated on the acceleration of the flow in a Coanda nozzle wall, thus contributing to help vectoring the exit jet flow. It will be shown that using only the plasma actuator it will be possible to vectorize the exit jet flow even under pure axial flow at the nozzle exit. Experimental results are obtained using flow visualization and Particle Image Velocimetry.

Jet Flow Control by DBD Plasma Actuator: Effect of Electrode Dimensions on Jet Diffusion

2011 ◽  
Author(s):  
Hongyu Jin ◽  
Takashi Ono ◽  
Motoaki Kimura
Keyword(s):  
Flow Control ◽  
Barrier Discharge ◽  
Jet Flow ◽  
Plasma Actuator ◽  
Plasma Actuators ◽  
Dbd Plasma ◽  
Flow Control Devices ◽  
Induced Flow ◽  
Control Devices ◽  
Effective Conditions

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.

Plasma actuators for airflow control: measurement of the non-stationary induced flow velocity

2005 ◽  
Vol 63 (6-10) ◽  
pp. 929-936 ◽  
Author(s):  
Maxime Forte ◽  
Luc Leger ◽  
Jérôme Pons ◽  
Eric Moreau ◽  
Gérard Touchard
Keyword(s):  
Flow Velocity ◽  
Plasma Actuators ◽  
Control Measurement ◽  
Induced Flow

Structure optimization of the AC-SDBD plasma actuator under duty-cycle mode

2018 ◽  
Vol 32 (26) ◽  
pp. 1850315 ◽  
Author(s):  
Yuexiao Long ◽  
Huaxing Li ◽  
Xuanshi Meng ◽  
Jia Li ◽  
Zhengchao Xiang
Keyword(s):  
Flow Control ◽  
Duty Cycle ◽  
Aerodynamic Characteristics ◽  
Plasma Actuator ◽  
Force Balance ◽  
Plasma Actuators ◽  
Dielectric Barrier ◽  
Barrier Discharge Plasma ◽  
Control Authority ◽  
Induced Flow

Alternating current dielectric barrier discharge plasma actuators driven by steady and unsteady mode were experimentally optimized in a static atmosphere. The purpose of this optimization is to enhance the effective controllability of flow control. Electrical properties were evaluated using the measured voltage, current and power consumption data. The dielectric barrier with different materials was tested and the aerodynamic characteristics were identified by particle image velocimetry and electronic force balance. Meanwhile, the duty-cycle technique was applied to operate the actuator in unsteady mode. The dynamic characteristics of induced flow were analyzed by processing the results with the phase-locked method. The development of induced flow structure at different frequencies was compared. Results showed that the plasma actuator with 4 mm-thick Teflon dielectric barrier induced the maximum force and velocity of 75 mN/m and 5.6 m/s, respectively. The discharge frequency has little effect on the control authority at the kilohertz level. The dimensionless area of the induced flow is about [Formula: see text] under steady actuation. The phase-locked results confirm that the scale and strength of the induced vortex vary with the duty-cycle frequencies. The effectiveness of unsteady flow control can be explained as the promotion of the boundary layer and the mainstream.

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
Keyword(s):  
Temperature Field ◽  
Surface Temperature ◽  
Flow Control ◽  
Active Flow Control ◽  
Plasma Actuator ◽  
Plasma Actuators ◽  
Dbd Plasma ◽  
Electrode Thickness ◽  
Dielectric Thickness ◽  
Surface Temperature Field

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.

scholarly journals A Novel Evaluation Method For Particle Deposition Measurement

Open Physics ◽  
2019 ◽  
Vol 17 (1) ◽  
pp. 927-934
Author(s):  
Tao Song ◽  
Chao Liu ◽  
Hengxuan Zhu ◽  
Min Zeng ◽  
Jin Wang
Keyword(s):  
Layer Thickness ◽  
Dielectric Layer ◽  
Gas Turbines ◽  
Particle Deposition ◽  
Optimization Design ◽  
Turbine Blades ◽  
Simulation Software ◽  
Circuit Board ◽  
Normal Operation ◽  
Mass Detection

Abstract Normal operation of gas turbines will be affected by deposition on turbine blades from particles mixed in fuels. This research shows that it is difficult to monitor the mass of the particles deposition on the wall surface in real time. With development of electronic technology, the antenna made of printed circuit board (PCB) has been widely used in many industrial fields. Microstrip antenna is first proposed for monitoring particles deposition to analyse the deposition law of the particles accumulated on the wall. The simulation software Computer Simulation Technology Microwave Studio (CST MWS) 2015 is used to conduct the optimization design of the PCB substrate antenna. It is found that the S11 of vivaldi antenna with arc gradient groove exhibits a monotonous increase with the increase of dielectric layer thickness, and this antenna is highly sensitive to the dielectric layer thickness. Moreover, a cold-state test is carried out by using atomized wax to simulate the deposition of pollutants. A relationship as a four number of times function is found between the capacitance and the deposited mass. These results provide an important reference for the mass detection of the particle deposition on the wall, and this method is suitable for other related engineering fields.

scholarly journals Comparison of Two-Equation Turbulence Models for Prediction of Heat Transfer on Film-Cooled Turbine Blades

1997 ◽  
Author(s):  
Vijay K. Garg ◽  
Ali A. Ameri
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Film Cooling ◽  
Turbine Blades ◽  
Three Dimensional ◽  
Turbulence Models ◽  
Computer Time ◽  
Suction Surface ◽  
The Heat Transfer Coefficient

A three-dimensional Navier-Stokes code has been used to compute the heat transfer coefficient on two film-cooled turbine blades, namely the VKI rotor with six rows of cooling holes including three rows on the shower head, and the C3X vane with nine rows of holes including five rows on the shower head. Predictions of heat transfer coefficient at the blade surface using three two-equation turbulence models, specifically, Coakley’s q-ω model, Chien’s k-ε model and Wilcox’s k-ω model with Menter’s modifications, have been compared with the experimental data of Camci and Arts (1990) for the VKI rotor, and of Hylton et al. (1988) for the C3X vane along with predictions using the Baldwin-Lomax (B-L) model taken from Garg and Gaugler (1995). It is found that for the cases considered here the two-equation models predict the blade heat transfer somewhat better than the B-L model except immediately downstream of the film-cooling holes on the suction surface of the VKI rotor, and over most of the suction surface of the C3X vane. However, all two-equation models require 40% more computer core than the B-L model for solution, and while the q-ω and k-ε models need 40% more computer time than the B-L model, the k-ω model requires at least 65% more time due to slower rate of convergence. It is found that the heat transfer coefficient exhibits a strong spanwise as well as streamwise variation for both blades and all turbulence models.

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