0pt; margin-right: 0pt;
text-align: center; text-indent: 0pt; line-height: 21pt;">Hojung Sin, R. C. M. Madhan and J. Reece Roth

UT Plasma Sciences Laboratory

Department of Electrical and Computer Engineering

The University of Tennessee

Knoxville, TN 37996-2100

E-mail: hsin@utk.edu, madan@utk.edu,
jrr@utk.edu

Presented at the 29th IEEE International Conference on Plasma
Science

Banff, Alberta, Canada, May 26-30, 200

*Supported in part by AFOSR Contract AF F49620-01-1-0425,
Dr.John Schmisseur, program manager

    ABSTRACT

 

,        We developed an apparatus
in the UT Plasma Sciences Laboratory to simultaneously generate a One
Atmosphere Uniform Glow Discharge Plasma (OAUGDP<sup>TM) [1], and effect
peristaltic flow acceleration of atmospheric air.  Lorentzian momentum
transfer from plasma ions accelerates the embedded neutral gas to several
tens of meters per second using paraelectric effects [2], and potentially
to hundreds of meters per second using peristaltic flow acceleration
by a traveling electrostatic wave[2,3].  Peristaltic flow acceleration
requires a polyphase power supply to excite the OAUGDPTM at progressive
voltage phase angles on a series of linear electrode strips [2,3]. 
This excitation produces a traveling wave analogous to the moving
lights on a theatre marquee, which accelerates the ions and neutral
gas to velocities that may approach Mach one. 

 

          
We used a polyphase signal generator of our own design to generate four
polyphase sinusoidal signals, each with a phase angle 45o greater than
that preceding.  These four signals can be adjusted by a single
amplitude control and are fed into four power amplifiers, the outputs
of which each drive the primary of a transformer.  The transformers
are capable of operating at kilohertz frequencies and have a high voltage
secondary winding capable of 5-6000 V rms with a center-tapped ground. 
The outputs of the four secondary windings provide eight phases separated
by 45o.  The flow accelerator panel consists of 24 parallel continuous
electrode strips and three complete phase periods.  The operating
frequency range is usually 2 10 kHz, the width of each electrode is
0.5 mm, and the distance between two adjacent electrodes is 1cm. 
The system is designed to operate without tracking (surface sparking)
when operated in normal air, and is theoretically capable of accelerating
gas flows to a velocity of over 100 m/s.  We have successfully
demonstrated peristaltically accelerated gas flows that have a high
velocity on the surface of the panel, and reverse direction when the
phasing of the electrodes is reversed. Peristaltic flow acceleration
should find many applications in subsonic plasma aerodynamics.

 

        
1.    J. R. Roth (1995).  Industrial Plasma Engineering, Volume
1 Principles, Institute of Physics Press, Bristol,   

              
UK   ISBN 0-7503-0318-2, Section 12.5.2, Section 9.6.3.

        
2.    J. R. Roth, Industrial Plasma Engineering: Volume 2, Applications to Nonthermal
Plasma Processing. Institute

               
of Physics Publishing, Bristol and Philadelphia 2001, ISBN 0-7503-545-2. 
Section 18.6.

         
3.   
J. R. Roth, 
"Method
and Apparatus for Covering Bodies with A Uniform Glow discharge Plasma
and Applications

              
Thereof". 
U. S. Patent #5,669,583, Issued Sept 23, 1997. 

For aerodynamic applications,
it is desired to form a thin layer of plasma on the surface of an airfoil
or fuselage and add or remove momentum from the boundary layer flow
by Lorentzian momentum transfer from the ions to the neutral gas.
To produce the required
plasma in air at one atmosphere, a One Atmosphere Uniform Glow Discharge
Plasma (OAUGDP) is
produced on a parallel array of electrode strips each energized with
the appropriate RF voltage and frequency.
Peristaltic plasma acceleration
results from a traveling electrostatic wave, analogous to the apparent
motion of  light in a phased array of bulbs on a theatre marquee.
To produce a traveling
electrostatic wave, adjacent electrodes are energized with progressively larger phase angles . The resulting horizontal electric field produces a body force that
accelerates the plasma.
Polyphase power supplies
that operate at kilohertz frequencies and RF voltages up to 10 kV</span><span
style=" font-family: 'Arial', 'Arial'; font-size: 16pt; font-weight: bold;
font-style: normal; text-decoration: none;"><sub>rms are not available
off-the-shelf. Here, we report our design of such a power supply, one
that uses commercially available components wherever possible.

INTRODUCTION

Two Subdisciplines of Plasma Physics

MHD