With
the end of the conflict, many of the organizations that were
mobilized for the war effort returned to their civilian work.
The Navy, however, was determined to continue its wartime
joint ventures with Harvard and other universities. When the
director of the Harvard research team, Dr. Eric Walker, left
for a position at Pennsylvania State University, the Navy
asked him to continue his undersea warfare research on its
behalf, a partnership that continues to this day at Penn State’s
Applied Research Laboratory (ARL).
“We
work with the submarine program in developing a range of technologies
to meet the needs of the fleet, especially research on propulsor
noise and new types of propulsors and propulsion systems,”
said Dr. Edward Liszka, ARL’s director. “This
is a technology-focused lab – that’s our product.
We believe you have to get out there and demonstrate new ideas,
establish credible performance, and address issues that often
prevent implementation of new technology in the fleet. Our
goal is to get the technology out there and get people to
use it. In that kind of development and testing, we often
find issues that are fixable in the next technology upgrade.”
Other
universities across the country, such as Johns Hopkins and
MIT, join Penn State in supporting the Navy by employing some
of the nation’s finest scientific talent to maintain
the Submarine Force on the cusp of the possible. In these
efforts, Navy-funded scientists use ARL equipment such as
the Garfield Thomas Water Tunnel, the most active closed-loop
test facility in the world, which serves a purpose similar
to that of an aeronautical wind tunnel in studying hydrodynamics
and hydroacoustics problems. This 48-inch diameter tunnel
is so large that at the time of its construction in 1949,
the building it is housed in had to be constructed around
it. When operating at a velocity of 35 knots, more than a
million gallons of water shoots through the test section every
three minutes.
“We’re
looking to get the most out of the things we do, Dr. Liszka
said. “The underlying science and physics we develop
from submarine research often give us the opportunity to do
things differently in other fields.”
One such
example is using ideas from submarine technology to build
a better lawnmower.
Talk to
ARL’s Dr. Courtney Burroughs for a few minutes, and
he will explain that the blades under a power mower are similar
to those of a ship’s propeller. His work to build quieter
submarines gave him an idea. “The propeller blade under
the deck of the mower is the thing that makes most of the
noise. But a lawn mower works in a much more hostile environment
than the ocean,” he said. Nevertheless, his team applied
to lawnmowers some of the same techniques they would use to
study a noisy propeller. “We put sensors on the blades
to look for unsteady pressure and impedance discontinuities,”
Dr. Burroughs explained. Understanding these phenomena led
to a contract to develop a quieter mower.
Moreover,
if lawnmower blades are analogous to a ship’s propellers,
then so are other fans – ranging from the ones used
to scrub dust out of the air in a coal mine to those employed
in a breathing machine to help people suffering from sleep
apnea. But Dr. Burroughs was not satisfied with constructing
a quieter fan for bedroom and coal-mine use. Using sensor
data on unsteady pressure and broadband noise that he gathered
from testing propellers in the ARL Water Tunnel, he discovered
another use for his findings.
“Auto
tires,” he said. “There’s a fairly violent
reaction where the rubber meets the road.” So, by embedding
sensors inside some steel-belted radials and measuring the
impacts of the underlying asphalt as if it were water rushing
past the edges of a propeller blade, the same science used
in reducing the noise of submarine propulsion could lead to
a quieter ride on the highway. |
