Performance Improvement of Turbomachinery Using Plasma Actuators

2011 ◽  
Author(s):  
Maria Grazia De Giorgi ◽  
Stefania Traficante ◽  
Antonio Ficarella
Keyword(s):  
Boundary Layer ◽  
Performance Improvement ◽  
Body Force ◽  
Barrier Discharge ◽  
Boundary Layer Separation ◽  
Plasma Actuators ◽  
Dielectric Barrier ◽  
Simulation Methodology ◽  
Compressor Performance ◽  
Naca 0015

This work deals with the computational modeling of the single dielectric barrier discharge (SDBD) plasma actuator and its applications as a flow actuator. In the literature, plasma actuators have been used especially in order to control boundary layer separation. The plasma acts as a momentum source to the boundary layer allowing it to remain attached throughout a large portion of the airfoil. The RANS simulations are performed using a CFD code in which the plasma force have been modeled as paraelectric force acting on the charged particles in the working flow. Using this numerical model, different cases have been simulated on NACA 0015 airfoil, depending on the direction of the force, to study the effect of the force on the flow and on the boundary layer. The best flow control solutions have been displayed when body force component in the direction straight along the flow is positive and the component normal to the flow is considered. Finally, this numerical simulation methodology has been used for the investigations on the potential of plasma actuators, to suppress the flow separation over a compressor blade. Specifically, the analysis has been focused to evaluate the increasing of the compressor performance depending on the actuator strength and position on the blade.

scholarly journals Conditioning of cross-flow instability modes using dielectric barrier discharge plasma actuators

2017 ◽  
Vol 833 ◽  
pp. 164-205 ◽  
Author(s):  
Jacopo Serpieri ◽  
Srikar Yadala Venkata ◽  
Marios Kotsonis
Keyword(s):  
Boundary Layer ◽  
Discharge Plasma ◽  
Barrier Discharge ◽  
Flow Instability ◽  
Cross Flow ◽  
Plasma Actuators ◽  
Dielectric Barrier Discharge Plasma ◽  
Dielectric Barrier ◽  
Instability Modes ◽  
Barrier Discharge Plasma

In the current study, selective forcing of cross-flow instability modes evolving on a $45^{\circ }$ swept wing at $Re=2.17\times 10^{6}$ is achieved by means of spanwise-modulated plasma actuators, positioned near the leading edge. In the perspective of laminar flow control, the followed methodology holds on the discrete roughness elements/upstream flow deformation (DRE/UFD) approach, thoroughly investigated by e.g. Saric et al. (AIAA Paper 1998-781, 1998), Malik et al. (J. Fluid Mech., vol. 399, 1999, pp. 85–115) and Wassermann & Kloker (J. Fluid Mech., vol. 456, 2002, pp. 49–84). The possibility of using active devices for UFD provides several advantages over passive means, allowing for a wider range of operating $Re$ numbers and pressure distributions. In the present work, customised alternating current dielectric barrier discharge plasma actuators have been designed, manufactured and characterised. The authority of the actuators in forcing monochromatic stationary cross-flow modes at different spanwise wavelengths is assessed by means of infrared thermography. Moreover, quantitative spatio-temporal measurements of the boundary layer velocity field are performed using time-resolved particle image velocimetry. The results reveal distinct steady and unsteady forcing contributions of the plasma actuator on the boundary layer. It is shown that the actuators introduce unsteady fluctuations in the boundary layer, amplifying at frequencies significantly lower than the actuation frequency. In line with the DRE/UFD strategy, forcing a sub-critical stationary mode, with a shorter wavelength compared to the naturally selected mode, results in less amplified primary vortices and related fluctuations, compared to the critical forcing case. The effect of the forcing on the flow stability is further inspected by combining the measured actuators body force with the numerical solution of the laminar boundary layer and linear stability theory. The simplified methodology yields fast and computationally cheap estimates on the effect of steady forcing (magnitude and direction) on the boundary layer stability.

Study of the Boundary Layer on a Plate Aerodynamically Induced by Multiple DBD Plasma Based on PIV

2013 ◽  
Vol 421 ◽  
pp. 163-167
Author(s):  
Feng Li ◽  
Chao Gao ◽  
Bo Rui Zheng ◽  
Yu Shuai Wang
Keyword(s):  
Boundary Layer ◽  
Dielectric Barrier Discharge ◽  
Barrier Discharge ◽  
Plasma Actuators ◽  
Dbd Plasma ◽  
Dielectric Barrier ◽  
Flow Acceleration ◽  
Plasma Actuation ◽  
Barrier Discharge Plasma ◽  
Layer Flow

The boundary layer aerodynamic flow acceleration with one atmosphere uniform induced by multiple dielectric-barrier-discharge plasma actuation were studied based on PIV. Through double actuators alternating discharge, the multiple dielectric barrier discharge mode have been proposed and tested. The efficiencies of the plasma actuators in Pulsed-pulsed, Steady-steady, Pulsed-steady and Steady-pulsed discharge modes were explored. Based on the above results, the boundary layer flow acceleration performance of multiple plasma actuators has been discussed and the more efficient discharge pattern has been proposed. The results of this study indicate that the airflow acceleration effect of multiple plasma actuators mainly occurs in paraelectric direction and the pulsed-pulsed is the more efficient multiple plasma actuation mode.

Single-dielectric barrier discharge plasma actuator modelling and validation

2011 ◽  
Vol 669 ◽  
pp. 557-583 ◽  
Author(s):  
BENJAMIN E. MERTZ ◽  
THOMAS C. CORKE
Keyword(s):  
Flow Control ◽  
Dielectric Barrier Discharge ◽  
Body Force ◽  
Barrier Discharge ◽  
Plasma Actuator ◽  
Time Dependent ◽  
Plasma Actuators ◽  
Force Vector ◽  
Dielectric Barrier ◽  
Flow Simulations

Single-dielectric barrier discharge (SDBD) plasma actuators have gained a great deal of world-wide interest for flow-control applications. With this has come the need for flow-interaction models of plasma actuators that can be used in computational flow simulations. SDBD plasma actuators consist of two electrodes: one uncovered and exposed to the air and the other encapsulated by a dielectric material. An AC electric potential is supplied to the electrodes. When the AC potential is large enough, the air in the region over the encapsulated electrode ionizes. The ionized air in the presence of the electric field results in a space–time dependent body force vector field. The body force is the mechanism for flow control. This study describes a semi-empirical model that has been developed to capture the dynamic nature of the local air ionization and time-dependent body force vector distribution. Validation of the model includes comparisons to experimentally measured space–time charge distribution and the time-resolved and time-averaged body force. Two flow simulations are then used to further validate the SDBD plasma actuator model. These involved an impulsively started plasma actuator in still air, and the flow around a circular cylinder in which plasma actuators were used to suppress the Karman vortex street. In both cases, the simulations agreed well with the experiments.

Impact of dielectric barrier discharge plasma on the wake of a wind turbine blade section oscillating in plunge

2021 ◽  
pp. 095765092110337
Author(s):  
GH Maleki ◽  
Ali R Davari ◽  
MR Soltani
Keyword(s):  
Wind Turbine ◽  
Dielectric Barrier Discharge ◽  
Turbine Blade ◽  
Discharge Plasma ◽  
Barrier Discharge ◽  
Wind Turbine Blade ◽  
Plasma Actuators ◽  
Dielectric Barrier Discharge Plasma ◽  
Dielectric Barrier ◽  
Barrier Discharge Plasma

Effects of dielectric barrier discharge plasma have been studied on the wake velocity profiles of a section of a 660 kW wind turbine blade in plunging motion in a wind tunnel. The corresponding unsteady velocity profiles show remarkable improvement when the plasma actuators were operating and the angles of attack of the model were beyond the static stall angles of the airfoil. As a result the drag force was considerably reduced. It is further observed that the plasma-induced flow attenuates the leading edge vortices that are periodically shed into wake and diminishes the large eddies downstream. The favorable effects of the plasma augmentation are shown to occur near the uppermost and lowermost positions of the plunging paths where the wake is primarily dominated by the vortices of the same sign. The wake structure in the presence of the flow induced by the plasma actuators shows that the actual effective angles of attack seen by the plunging airfoil reduces in comparison with that for the case of the plasma augmentation off situation.

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