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Experience
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Senior Engineer
QinetiQ North America
Technology Solutions Group
350 Second Avenue
Waltham, MA 02451-1196
July 1998 -- Present
Current Projects:
- Controller development
for the Electromagnetic Aircraft Launch System (EMALS) System Development and
Demonstration (SDD) phase, subcontracting to General Atomics. This phase involves the
design and construction of a shipboard-ready linear motor capable of
catapulting aircraft off the decks of Navy carriers. [article][mov]
Completed Projects Include:
- Magnetic Actuator
design and system model for the Phase II SBIR, Development
of a micro-pumped cryogenic two-phase heat transport system.
- Motor design and
controller development for the EMALS Program Definition Program Definition
phase, subcontracting to General Atomics. The PDRR phase culminated in the
successful deadload testing of a full-scale prototype linear motor system
at NAES Lakehurst. [article][mov]
- Controller development
for the Navy’s Advance Arresting Gear (AAG) program, subcontracting to
General Atomics.
- Design of synchronous
PM linear motor, electrodynamic "null-flux" suspension, and
eddy current brake for NASA's
Maglifter program. This project involved the successful design and
construction of a bearingless motor that accelerates 6 kg mass to a
speed of 55 mph over the length of a 20 foot drive section.
[avi]
- Design of slotless
axial flux linear induction motors for the Navy Electric
Aircraft Recovery System (EARS) Phase II SBIR. This project involved
the successful design, construction, and testing of a scale model
arrestor system for Navy aircraft carriers. This system accelerates a
100 lb. mass to a speed of approximately 25 mph using an air cannon. The
mass then hooks onto a cable, either end of which is connected to a
vector controlled linear induction motor. By applying carefully
controlled forces to the ends of the cable, the mass is brought to a
halt. [avi]
- Creation and
implementation of a model-based reasoning algorithm for power system
reconfiguration for the Navy Nonlinear Power Systems Phase II
SBIR.
- Analysis of an
electrodynamic suspension for a rocket sled, done as a subcontractor to
General Atomics' Holloman High Speed Test Track Upgrade program.
- Design of a
block-switched linear transformer intended to supply field excitation
for a large linear synchronous machine under the Navy Phase I SBIR,
Electric Power Transfer.
Independent Consultant
Brighton, MA
August 1997 -- July 1998
Design and analysis of novel electric machines. Projects included:
- Created a
full-featured finite element
package for the solution of 2D planar and axisymmetric problems in
low frequency magnetics under Windows. [executable]
[source]
- Testing of a Hybrid PM Generator
for SatCon.
- Creation of a
Win95/98/NT program for the weight-optimal design of magnetic bearings
for gas turbine engines for SatCon.
- Analysis of a
Homopolar PM Bias magnetic bearing system for Avcon.
- Design of passive
magnetic bearings and eddy current dampers for energy storage flywheels
for Beacon Power.
Research and Development Engineer
SatCon Technology Corporation
161 First Street
Cambridge, MA 02142-1221
July 1996 -- July 1997
Design and analysis of novel electromechanical machines; Design and
implementation of multiple input/multiple output controllers. While at
SatCon, work included:
- Design of magnetic
bearings for energy storage flywheels including both active and passive
magnetic bearings.
- Design of magnetic
bearings for gas turbine engines. These designs focused on achieving the
low bearing losses and high speeds possible with magnetic bearings while
tolerating the extremely high temperatures present in gas turbine engine
cores. Severe constraints on bearing size and weight are also driving
considerations in these designs.
- Principal Investigator
for a precision positioning system for silicon photolithography.
Designed Lorentz actuators employed by the system, and wrote C code
implementing a 1400 Hz, three degree-of-freedom control loop yielding
positioning accuracy of +-50 nm.
- Design of a 10 kW
hybrid PM alternator. The alternator is excited via permanent magnets
but has an additional stationary field coil that can be used to regulate
output voltage. The alternator was modeled both analytically and via a
custom finite element program that was required to account for the
alternator's intrinsically three-dimensional flux paths. This work was
patented as US6097124
- Authoring of several
SBIR grant proposals relating to magnetic bearings, dynamics, and controls.
Research Assistant
University of Virginia
Department of Mechanical, Aerospace
and Nuclear Engineering
August 1990 -- May 1996
While at the University of Virginia, work included:
- Design and construction
of a six degree of freedom large-gap magnetic actuator to be used as an
experimental apparatus for the study of vortex breakdown in fluids. Work
sponsored by NSF.
- Development of a
hybrid analytical/finite element model of the effects of eddy currents,
flux leakage, and fringing in magnetic bearings. Work sponsored by
Kingsbury, Inc.
- Derivation of a
general method for the control the Magnetic Stereotaxis System, a
large-gap magnetic actuator used to perform neurosurgery. Work done in
conjunction with the Department of Physics, University of
Virginia.
- Design of passive
magnetic bearings for use in an artificial heart.
- Development of
fault-tolerant magnetic bearing control strategies. Work sponsored by
the Mobil Corporation.
- Investigation of the feasibility
of the use of neural networks in automobile collision prediction. Work
sponsored by the National Highway Transportation Safety Administration.
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Education
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Doctor of Philosophy, Mechanical and Aerospace
Engineering, May 1996
University of Virginia, School of Engineering and Applied Science,
Charlottesville, VA
Dissertation: Optimal
solutions to the inverse problem in quadratic magnetic actuators.
Abstract: The formulation of current-to-force relationships for magnetic
actuators proceeds in a fairly straightforward fashion from Maxwell's
equations for magnetostatic problems. However, the inverse problem of
determining a set of currents to realize a desired force is less well
understood. Historically, this problem has been relatively neglected because
actuators were built in symmetric geometries where a viable solution could be
intuited. Recently, calls for both optimal actuator performance and fault
tolerance have necessitated the formulation of general solution methodologies
for magnetic actuators. This work will consider such formulations for
magnetic actuators whose current-to-force relationships are homogeneous
quadratics. This class of actuators includes active magnetic bearings and the
magnetic stereotaxis system.
Advisor: Eric H. Maslen
Master of Science, Mechanical and Aerospace Engineering, May 1993
University of Virginia, School of Engineering and Applied Science
Thesis: Pre-crash sensing and restraint optimization for automobiles.
Advisor: Eric H. Maslen
Bachelor of Science, Mechanical Engineering, May 1990
Duke University, School of Engineering, Durham, NC
Cum Laude
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Publications
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D.C. Meeker and E.H. Maslen,
"Analysis and Control of a Three Pole Radial Magnetic Bearing,"
Tenth International Symposium on Magnetic Bearings, Martigny, Switzerland, Aug. 2006.
D.C. Meeker, A.V. Filatov, and E.H. Maslen,
"Effect of
Magnetic Hysteresis on Rotational Losses in Heteropolar Magnetic
Bearings," IEEE Transactions on Magnetics, 40(5):3302-3307,
Sept. 2004.
D.C. Meeker and E. H.
Maslen, "Prediction of rotating losses in heteropolar radial
magnetic bearings," Journal of Tribology, 120(3):629-635, July
1998.
D. C. Meeker, E. H. Maslen, and M.
D. Noh, "An augmented circuit model for magnetic bearings including
eddy currents, fringing, and leakage," IEEE Transactions on
Magnetics, 32(4):3219-3227, July 1996.
D. C. Meeker, E. H. Maslen, R. R.
Ritter, and F. M. Creighton, "Optimal realization
of arbitrary forces in a magnetic stereotaxis system," IEEE
Transactions on Magnetics, 32(2):320-328, March 1996.
E. H. Maslen and D. C. Meeker, "Fault-tolerance of
magnetic bearings by generalized bias current linearization," IEEE
Transactions on Magnetics, 31(3):2304-2314, May 1995.
D. C. Meeker and M. A. Townsend, "Motions of a powered
top with a spherical tip on a curved surface," Shock and
Vibrations Journal, 2(1):23-32, Jan. 1995. [exe]
D. C. Meeker and D. M. Dozor,
"Thermomagnetic optimization of solenoidal magnetostrictive
actuators," SPIE 6th Annual International Symposium on Smart Structures
and Materials, Newport Beach, CA, March 1999.
D. C. Meeker, E. H. Maslen, and M. Kasarda,
"Influence of actuator geometry on rotating losses in heteropolar
magnetic bearings," Sixth International Symposium on Magnetic Bearings,
Cambridge, MA, Aug. 1998.
D. C. Meeker and E. H. Maslen, "A thin plate model
of rotating losses in magnetic bearings," Fifth International
Symposium on Magnetic Bearings, Kanazawa, Japan, Aug. 1996.
D. C. Meeker and E. H. Maslen, "Power optimal
solution of the magnetic inverse problem for heteropolar magnetic
bearings," Fifth International Symposium on Magnetic Bearings,
Kanazawa, Japan, Aug. 1996.
D. C. Meeker, E. H. Maslen, and M. D. Noh, "A wide bandwidth
model for the electrical impedance of magnetic bearings," Third
International Symposium on Magnetic Suspension Technology, Tallahassee, FL,
Dec. 13-15, 1995.
E. H. Maslen and D. C. Meeker, "Bias linearization and decoupling for
active magnetic bearings: a generalized theory," Fourth International
Symposium on Magnetic Bearings, Zurich, Switzerland, 1994.
D. C. Meeker and M. A. Townsend, "Motions of a powered top with a
spherical tip on a curved surface," ASME Winter Annual Meeting, New
Orleans, LA, 1993.
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Patents
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US6097124: Hybrid
permanent magnet/homopolar generator and motor. Inventors: Rao, Gita P.;
Kirtley, James L.; Meeker, David C.; Donegan,Kevin J. Assignee: Satcon
Technology Corporation. Date of Patent: August 1, 2000
US2005/0147512: Rotary pump with electromagnetic LCR bearing.
Inventors: Chen, Hsiang Ming; Smith, William A.; Vitale, Nicholas G.; Chapman,
Peter A. JR.; Donahue, Arthur C.; Meeker, David C. Assignees: Foster-Miller, Inc.;
The Cleveland Clinic Foundation. Date of Patent Application: July 7, 2005
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