Effect of DBD Plasma Actuator Geometry and Excitation for Producing Transient Growth Modes in a Laminar Boundary Layer

2012 ◽  
Author(s):  
Luke Osmokrovic ◽  
Ronald Hanson ◽  
Philippe Lavoie
Keyword(s):  
Boundary Layer ◽  
Laminar Boundary Layer ◽  
Plasma Actuator ◽  
Transient Growth ◽  
Dbd Plasma ◽  
Growth Modes

Effect of the discharge constriction in DBD plasma actuator on the laminar boundary layer

2018 ◽  
Vol 116 ◽  
pp. 1326-1340 ◽  
Author(s):  
Ivan Moralev ◽  
Viktoria Sherbakova ◽  
Igor Selivonin ◽  
Valentin Bityurin ◽  
Maxim Ustinov
Keyword(s):  
Boundary Layer ◽  
Laminar Boundary Layer ◽  
Plasma Actuator ◽  
Dbd Plasma

Turbine Cascade Flow Control Using a “Wake Filling” Pulsed Plasma Actuator

2005 ◽  
Author(s):  
H. Perez-Blanco ◽  
Robert Van Dyken ◽  
Aaron Byerley ◽  
Tom McLaughlin
Keyword(s):  
Boundary Layer ◽  
Pressure Gradient ◽  
Laminar Boundary Layer ◽  
Separation Bubble ◽  
Adverse Pressure Gradient ◽  
Suction Side ◽  
Plasma Actuator ◽  
Pulsed Plasma ◽  
Power Cost ◽  
Hot Film

Separation bubbles in high-camber blades under part-load conditions have been addressed via continuous and pulsed jets, and also via plasma actuators. Numerous passive techniques have been employed as well. In this type of blades, the laminar boundary layer cannot overcome the adverse pressure gradient arising along the suction side, resulting on a separation bubble. When separation is abated, a common explanation is that kinetic energy added to the laminar boundary layer speeds up its transition to turbulent. In the present study, a plasma actuator installed in the trailing edge (i.e. “wake filling configuration”) of a cascade blade is used to excite the flow in pulsed and continuous ways. The pulsed excitation can be directed to the frequencies of the large coherent structures (LCS) of the flow, as obtained via a hot-film anemometer, or to much higher frequencies present in the suction-side boundary layer, as given in the literature. It is found that pulsed frequencies much higher than that of LCS reduce losses and improve turning angles further than frequencies close to those of LCS. With the plasma actuator 50% on time, good loss abatement is obtained. Larger “on time” values yield improvements, but with decreasing returns. Continuous high-frequency activation results in the largest loss reduction, at increased power cost. The effectiveness of high frequencies may be due to separation abatement via boundary layer excitation into transition, or may simply be due to the creation of a favorable pressure gradient that averts separation as the actuator ejects fluid downstream. Both possibilities are discussed in light of the experimental evidence.

Turbulent Boundary Layer Separation Control by Using DBD Plasma Actuators: Part II—Numerical Model Validation and Parametric Study

2010 ◽  
Author(s):  
Xiaofei Xu ◽  
Huu Duc Vo ◽  
Njuki Mureithi ◽  
Xue Feng Zhang
Keyword(s):  
Boundary Layer ◽  
Turbulent Boundary Layer ◽  
Parametric Study ◽  
Boundary Layer Separation ◽  
Plasma Actuator ◽  
Plasma Actuators ◽  
Low Flow ◽  
Dbd Plasma ◽  
Layer Separation ◽  
Flow Velocities

Following an experimental investigation into suppression of a 2-D turbulent boundary layer separation with dielectric barrier discharge (DBD) plasma actuators, the present work investigates the concept numerically. The purpose is to develop and validate a simulation tool that captures the flow physics and carry out a parametric study of the concept at flow regimes beyond the current flow control capability of plasma actuators of conventional strength. First, a plasma actuator model is integrated into the commercial computational fluid dynamics (CFD) code ANSYS CFX to simulate the effects of plasma actuation. This computational tool is validated through comparison of results with the experimental results for pulsed actuation in quiescent air and for the control of a turbulent boundary layer separation at low flow velocities. It is shown that CFX with an integrated plasma model can capture the main experimentally observed effects of DBD actuators on turbulent boundary layer separation. Subsequently, this numerical approach is used, with increased plasma actuator strength, to study the influence of different actuation parameters (e.g., actuation location, direction and frequency) on suppression of turbulent boundary layer separation at higher flow velocities.

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