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.

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.

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

Analysis and Implementation of Dielectric Barrier Discharge Plasma Actuators for Ground Vehicles Wake Reduction

2021 ◽  
Author(s):  
F. F. Rodrigues ◽  
M. Moreira ◽  
J. Pascoa
Keyword(s):  
Dielectric Barrier Discharge ◽  
Discharge Plasma ◽  
Barrier Discharge ◽  
Active Flow Control ◽  
Plasma Actuators ◽  
Ground Vehicles ◽  
Dielectric Barrier Discharge Plasma ◽  
Dielectric Barrier ◽  
Barrier Discharge Plasma ◽  
Active Flow

Abstract Plasma actuators are promising devices with several possible applications in active flow control field. One of the possible applications of these devices is wake reduction in ground vehicles. By delaying the flow separation and reducing the wake of the flow, these devices allow to reduce the drag which, in turns, leads to important savings in terms of fuel consumption. In the current work, the operation of dielectric barrier discharge plasma actuators is studied considering their application for active flow control in ground vehicles. A plasma actuator was fabricated and experimentally characterized in terms of electrical and mechanical features. A ground vehicle model, with different rear slant angles, was constructed and preliminary tests were performed in a wind tunnel. The dielectric barrier discharge plasma actuator was implemented on the top rear part of the model, in the first separation zone of the flow, in order to attach the flow to the surface and reduce the wake flow. The experimental tests were performed for rear slant angles of 30°, 45° and 60°. The different vehicle models were tested for a flow velocity of 5m/s. Flow visualization and velocity measurements were performed in order to analyze the flow behavior and the active flow control effect obtained by the plasma actuation. It is shown that by using plasma actuators on the rear of the model, the plasma actuation pulls the flow toward the surface and reduce the wake of the flow.

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.

Dielectric Barrier Discharge (DBD) Plasma Actuators for Flow Control in Turbine Engines: Simulation of Flight Conditions in the Laboratory by Density Matching

2019 ◽  
Vol 36 (2) ◽  
pp. 157-173
Author(s):  
David E. Ashpis ◽  
Douglas R. Thurman
Keyword(s):  
Flow Control ◽  
Dielectric Barrier Discharge ◽  
Barrier Discharge ◽  
Test Chamber ◽  
Plasma Actuators ◽  
Chamber Pressure ◽  
Turbine Engines ◽  
Dbd Plasma ◽  
Dielectric Barrier ◽  
Actuator Performance

Abstract We address requirements for laboratory testing of AC Dielectric Barrier Discharge (AC-DBD) plasma actuators for active flow control in aviation gas turbine engines. The actuator performance depends on the gas discharge properties, which, in turn, depend on the pressure and temperature. It is technically challenging to simultaneously set test-chamber pressure and temperature to the flight conditions. We propose that the AC-DBD actuator performance depends mainly on the gas density, when considering ambient conditions effects. This enables greatly simplified testing at room temperature with only chamber pressure needing to be set to match the density at flight conditions. For turbine engines, we first constructed generic models of four engine thrust-classes; 300-, 150-, 50-passenger, and military fighter, and then calculated the densities along the engine at sea-level takeoff and altitude cruise conditions. The range of chamber pressures that covers all potential applications was found to be from 3 to 1256 kPa (0.03 to 12.4 atm), depending on engine-class, flight altitude, and actuator placement in the engine. The engine models are non-proprietary and can be used as reference data for evaluation requirements of other actuator types and for other purposes. We also provided examples for air vehicles applications up to 19,812 m (65,000 ft).

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