Heat Transfer,
Combustion, and Energy Systems
Acoustics and Dynamics Research Group
The
graduate research program in Acoustics and Dynamics
is devoted to an exploration of vibratory
phenomena that are encountered in structural systems, in
the air, and in the water. In fluid media, these
vibrations are called sound, so the area is referred to as
acoustics, but many of the questions and
research tools are common to all areas. The basic objective
shared by the projects is to understand the
mechanisms by which the vibration or sound is initially generated,
or modified as it propagates, or
detected by the receiving transducer. In many cases, this
information can be used to characterize the
propagation medium. In some cases, this will lead to concepts
for reducing the signal, but there are
many situations where it is desirable to enhance it.
A recent
project has explored the measurement of vibration
using laser Doppler techniques. The
concept is to make noncontact, high resolution measurements
of surface motion by exploiting the
Doppler shift that results when a laser beam reflects
off a vibrating body. The technique is being used to
characterize the rubber-like coatings used to quiet
submarines. A very different line of research is
devoted to using ultrasonic signals to detect defects
in structures, for example, helicopter parts. A
project that combines ultrasonics with laser techniques
is 
material characterization by noncontact laser
ultrasonics, that is, when ultrasound is generated and
detected by laser beams. An interesting biological
project is exploring the effects of loud signals in
the water, with the objective of assisting navy divers.
One of the uses of the anechoic testing facility is
to improve analysis and measurement techniques for
reducing noise in various systems; for example, interior
cabin noise in
aircraft or automobiles, or fan and pump noise. It is
also being used to
study and calibrate acoustic sources and receivers,
and acoustic
materials. A recent use of the facility included the
assessment of the
impact of protective clothing, such as an air-fed plastic
suit, on the
ability of a wearer to hear an alarm signal.
A novel project is exploring the use of wedges to produce shock absorbers that are effective for both vibration reduction and shock isolation, which present conflicting requirements for design. A recent project has begun to examine concepts for experimental modal analysis that would be suitable for heavily damped and rotating systems, as well as systems that have closely spaced natural frequencies. Each of these applications presents significant difficulties for current techniques.
Research funding is derived primarily from the Office of Naval Research, the National Science Foundation, the National Aeronautics and Space Administration, and industries such as Ford Motor Company, Cummins Engine Co., Lockheed-Martin Corporation, Newport News Shipbuilding, and Tenneco.
Research Facilities
|
Active Control
Laboratory --- |
J. Erskine Love Jr. Manufacturing
Building (Faculty and graduate student offices and labs) --- |
Integrated Acoustics Laboratory --- |
Laboratory for Functional Materials
at Georgia Tech Lorraine --- |
Underwater
Acoustics Research Laboratory |
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