ScienceDaily (Nov. 19, 2012) — Owls have
the uncanny ability to fly silently, relying on specialized plumage to reduce
noise so they can hunt in acoustic stealth. Researchers from the University of
Cambridge, England, are studying the owl's wing structure to better understand
how it mitigates noise so they can apply that information to the design of
conventional aircraft.
They present their findings at the American
Physical Society's (APS) Division of Fluid Dynamics meeting, held Nov. 18 --
20, in San Diego, Calif.
"Many owl species have developed
specialized plumage to effectively eliminate the aerodynamic noise from their
wings, which allows them to hunt and capture their prey using their ears
alone," said Justin Jaworski with the department of applied mathematics
and theoretical physics at the University of Cambridge. "No one knows
exactly how owls achieve this acoustic stealth, and the reasons for this feat
are largely speculative based on comparisons of owl feathers and physiology to
other not-so-quiet birds such as pigeons."
All wings, either natural or engineered, create
turbulent eddies as they cut through the air. When these eddies hit the
trailing edge of the wing, they are amplified and scattered as sound.
Conventional aircraft, which have hard trailing edges, are particularly noisy
in this regard.
No comments:
Post a Comment