characterization and flow physics of plasma synthetic jet actuators

290 Pages·2016·12.34 MB·English

by  Arvind Santhanakrishnan

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University of Kentucky Doctoral Dissertations Graduate School
2007
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Arvind Santhanakrishnan
University of Kentucky, [email protected]
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Santhanakrishnan, Arvind, "CHARACTERIZATION AND FLOW PHYSICS OF PLASMA SYNTHETIC JET
ACTUATORS" (2007). University of Kentucky Doctoral Dissertations. 545.
https://uknowledge.uky.edu/gradschool_diss/545
This Dissertation is brought to you for free and open access by the Graduate School at UKnowledge. It has been
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ABSTRACT OF DISSERTATION
Arvind Santhanakrishnan
The Graduate School
University of Kentucky
2007
CHARACTERIZATION AND FLOW PHYSICS OF
PLASMA SYNTHETIC JET ACTUATORS
ABSTRACT OF DISSERTATION
A dissertation submitted in partial fulfillment of the
requirements for the degree of Doctor of Philosophy in
Mechanical Engineering in the College of Engineering
at the University of Kentucky
By
Arvind Santhanakrishnan
Lexington, Kentucky
Director: Dr. Jamey D. Jacob, Associate Professor of Mechanical and Aerospace Engineering
Oklahoma State University, Stillwater, Oklahoma
2007
Copyright (cid:13)c by Arvind Santhanakrishnan 2007
ABSTRACT OF DISSERTATION
CHARACTERIZATION AND FLOW PHYSICS OF
PLASMA SYNTHETIC JET ACTUATORS
Plasmasyntheticjetactuatorsareinvestigatedexperimentally,inwhichthegeometrical
designofsingledielectricbarrierdischarge(SDBD)plasmaactuatorsismodifiedtoproduce
zero-mass flux jets similar to those created by mechanical devices. The SDBD plasma
actuator consists of two rectangular electrodes oriented asymmetrically and separated by a
layerofdielectricmaterial. Underaninputofhighvoltage,highfrequencyACorpulsedDC,
a region of plasma is created in the interfacial air gap on account of electrical breakdown
of the ambient air. A coupling between the electric field in the plasma and the neutral
air near the actuator is introduced, such that the latter experiences a net force which
results in a horizontal wall jet. This effect of the actuator has been demonstrated to
be useful in mitigating boundary layer separation in aerodynamic flows. To increase the
impact that a plasma actuator may have on the flow field, this research investigates the
development and characterization of a novel flow control device, the plasma synthetic jet
actuator, which tailors the residual air in the form of a vertical jet resembling conventional
continuous and synthetic jets. This jet can be either three dimensional using annular
electrode arrays, or nearly two dimensional using two rectangular strip exposed electrodes
and one embedded electrode. Detailed measurements on the isolated plasma synthetic jet
reveal that pulsed operation of the actuator results in the formation of multiple counter-
rotating vortical structures in the flow field. The output jet velocity and momentum are
found to be higher for unsteady pulsing as compared to steady operation. In the case of
flow over a flat plate, the actuator is observed to create a localized interaction region within
which the baseline flow direction and boundary layer characteristics are modified. The
efficiency of the actuator in coupling momentum to the neutral air is found to be related
to the plasma morphology, pulsing frequency, actuator dimension, and input power. An
analytical scaling model is proposed to describe the effects of varying the above variables
on the output jet characteristics and actuator efficiency, and the experimental data is used
for model validation.
KEYWORDS: Active Flow Control, Plasma Actuators, Synthetic Jets, Particle Image Ve-
locimetry, Jet Flows.
Arvind Santhanakrishnan
August 31, 2007
CHARACTERIZATION AND FLOW PHYSICS OF
PLASMA SYNTHETIC JET ACTUATORS
By
Arvind Santhanakrishnan
Dr. Jamey D. Jacob
(Director of Dissertation)
Dr. L. S. Stephens
(Director of Graduate Studies)
August 31, 2007
(Date)
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Name Date
DISSERTATION
Arvind Santhanakrishnan
The Graduate School
University of Kentucky
2007
CHARACTERIZATION AND FLOW PHYSICS OF
PLASMA SYNTHETIC JET ACTUATORS
DISSERTATION
A dissertation submitted in partial fulfillment of the
requirements for the degree of Doctor of Philosophy in
Mechanical Engineering in the College of Engineering
at the University of Kentucky
By
Arvind Santhanakrishnan
Lexington, Kentucky
Director: Dr. Jamey D. Jacob, Associate Professor of Mechanical and Aerospace Engineering
Oklahoma State University, Stillwater, Oklahoma
2007
Copyright (cid:13)c by Arvind Santhanakrishnan 2007
This dissertation is dedicated to the loving memory of my grandparents,
Lakshmi and Parthasarathy. Thank you for always watching over me.