BUFFALO, N.Y. -- The secret to the flight of the hummingbird and
other tiny birds and insects lies in the looping, swirling flow of
air, called a vortex, that their flapping wings create.
These aerodynamically unconventional flows are the inspiration
behind new research by a University at Buffalo scientist who hopes
to understand the nature of the three-dimensional vortex formation
process so that it can be optimized.
The UB research is motivated by the need to gather real-time
intelligence in particularly challenging environments; these
include remote caves and tunnels or complex building corridors in
cities, neither of which can easily be penetrated by conventional,
unmanned aircraft or spy satellites. One solution being explored is
the design of tiny, flying surveillance devices called micro-air
vehicles that are bio-inspired, based on lessons drawn from the
behavior of insects and birds.
"In surveillance applications, these small, autonomous or
remote-controlled vehicles would be ideal because they would be
able to penetrate these complex kinds of terrain and gather
first-hand, real-time intelligence," says Matthew Ringuette, PhD,
assistant professor in the Department of Mechanical and Aerospace
Engineering in the UB School of Engineering and Applied
But developing flying devices on the scale of just a few inches
requires a much greater understanding of the propulsion systems of
tiny birds and insects.
"When you get down to such small sizes and slow speeds,
conventional aerodynamics no longer apply," explains Ringuette.
Instead of the streamlined flow that occurs when air flows over
the wing of a jet, for example, fluid dynamics at the much smaller
scales of hummingbird wings are characterized by swirling flow and
vortex formation, similar to that which is created by canoe paddles
as they are pushed through the water.
"Animals, such as insects and birds, take advantage of this
vortex formation to achieve flight and outstanding
maneuverability," he explains.
Ringuette's research is designed to discover how vortex growth
and development scales with wing size, motion and shape, so that
the wing of a micro-air vehicle can be optimized for maximum
propulsive force and efficiency. He notes that this work is
fundamental to three-dimensional vortex formation in general, which
occurs in a variety of settings, from cardiovascular flows to
He will conduct experiments using a robotic, flapping-wing model
that will propel itself through a 13-foot by 4-foot by 3-foot water
tank in his Vortex Dynamics and Bio-Inspired Propulsion Lab at UB.
In water, these flapping wing models can produce at larger scales
vortex formation similar to that exhibited by birds and insects.
Ringuette will be making quantitative measurements of wing flow
velocity and the forces at work during propulsion, supplemented by
dye visualization to obtain a picture of the three-dimensional
Ringuette is conducting this research as a result of his Young
Investigators Research Program award from the Air Force Office of
Scientific Research. He is one of 38 young scientists nationwide
who received this award, the purpose of which is to foster creative
research in science and engineering, enhance early career
development of outstanding young researchers and increase
opportunities for young researchers to recognize the Air Force
mission and related challenges in science and engineering.
The University at Buffalo is a premier research-intensive public
university, a flagship institution in the State University of New
York system and its largest and most comprehensive campus. UB's
more than 28,000 students pursue their academic interests through
more than 300 undergraduate, graduate and professional degree
programs. Founded in 1846, the University at Buffalo is a member of
the Association of American Universities.