|NOTE TO JOURNALISTS:
A photo of Fazle Hussain is available on the Web at http://www.uh.edu/admin/media/nr/
2006/12dec/fhussain_photo.html. A high-resolution photo is available
by contacting Lisa Merkl.
TURNING ‘DELAYED’ TO ‘ON
TIME’ GOAL OF UH PROF
IN AIRCRAFT TURBULENCE STUDIES
Fazle Hussain Receives $300K NSF Grant, Embarks on Research to Reduce
HOUSTON, Dec. 13, 2006 – Gridlock on airport runways is
a common part of holiday travel, but one University of Houston engineering
professor is researching ways to reduce airport delays by making
runways usable more quickly.
Planes stir up the air considerably into swirling vortices when
they take off and land, so the air has to settle down before any
other plane can move safely through the space or consequences can
be disastrous. The process can take minutes, consuming valuable
time on airport runways both for takeoffs and landings. Multiplied
over many arrivals and departures, these waits can contribute to
long flight delays, especially at busier airports and during holiday
congestion. The results are inconvenience and wasted time.
Working from a $300,000 grant from the National Science Foundation
(NSF), Fazle Hussain, the Hugh Roy & Lillie Cranz Cullen Distinguished
Professor of Mechanical Engineering at UH, is researching ways to
reduce such delays by saving time between aircrafts during takeoffs
and during landings.
Hussain’s approach is to speed the breakdown of vortices
– whirling masses of air that suck everything nearby toward
the center – to turbulence between planes. These tornado-like
vortices left behind the generating aircraft are long-lived and
create a potential hazard for trailing aircraft until broken down
into turbulence, the latter of which takes precious time.
“When these delays become a big enough problem at an airport,
the typical solution is to build a new runway. This can be costly,
since the average runway costs more than $2 billion to build, and
there isn’t enough land to build new runways in busy airports
or in many big cities,” Hussain said. “To avoid these
costs while still easing congestion, we will attempt to cause trailing
vortices to break down into turbulence more quickly than they do
naturally, thus encouraging their decay and making runways usable
more quickly. All this is expected to be accomplished through the
creation of near-axis swirl as suitable perturbations induced in
The research specifically concentrates on an aircraft’s pair
of trailing vortices that are the swirling flow behind an airplane
caused by the difference in air pressure above and below the plane’s
wings. These vortices form at the tips of the wings and can remain
energetic for large enough distances behind a plane to present dangers
to other airplanes that encounter them. All such vortices naturally
transition into turbulence eventually due to small disturbances
that disrupt the orderly circular flow of air. The turbulent trailing
vortex then decays relatively quickly, making it safe for additional
aircraft to pass through the area once occupied by a vortex.
Initially using computer modeling, Hussain is testing the effects
of adding an appropriate small device to the tip of an aircraft’s
wings that will cause a rotation of air to introduce disturbances
into the trailing vortex instead of waiting for them to occur naturally,
resulting in the entire vortex-to-decayed-turbulence process being
shortened. Hussain’s goals are to show that speeding the transition
to turbulence is achievable, as well as be able to demonstrate and
explain why and how it is possible.
A fluid dynamicist who specializes in aerodynamics, vortex dynamics
and turbulence, Hussain has focused on the search for ‘order
within disorder’ in fluid turbulence. As director of UH’s
Institute of Fluid Dynamics and Turbulence, he is one of the leading
experts in the field. He has published more than 250 scientific
papers on this and related topics and is one of the most decorated
fluid dynamicists, winning four of the field’s most coveted
awards. Hussain was one of the first to recognize that the organized
motion underlying the seemingly random motion of turbulence is the
key to understanding turbulence and to controlling turbulent flows
for technological benefit. Through his Aerodynamics and Turbulence
Laboratory at UH, he is constantly placing together pieces of the
puzzle to find significant applications for advances in the field.
Coming to UH in 1971, Hussain earned his doctoral and master’s
degrees in mechanical engineering from Stanford University and his
bachelor’s degree, also in mechanical engineering, from Bangladesh
University of Engineering and Technology. Elected to the National
Academy of Engineering (NAE) in 2001, Hussain was most recently
elected as an officer for a three-year term to the NAE’s mechanical
engineering section that will include one-year terms as secretary
and vice-chair, culminating with the position of chair, one of the
most prestigious positions in the mechanical engineering community.
He plays an active role in the Academy of Engineering, Medicine
and Science of Texas and will chair its “Cardiovascular Engineering”
session Jan. 5, 2007, during its annual conference in Austin, Texas.
About the University of Houston
The University of Houston, Texas’ premier metropolitan research
and teaching institution, is home to more than 40 research centers
and institutes and sponsors more than 300 partnerships with corporate,
civic and governmental entities. UH, the most diverse research university
in the country, stands at the forefront of education, research and
service with more than 35,000 students.
About the Cullen College of Engineering
UH Cullen College of Engineering has produced five U.S. astronauts,
ten members of the National Academy of Engineering, and degree programs
that have ranked in the top ten nationally. With more than 2,600
students, the college offers accredited undergraduate and graduate
degrees in biomedical, chemical, civil and environmental, electrical
and computer, industrial, and mechanical engineering. It also offers
specialized programs in aerospace, materials, petroleum engineering
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