Andrew Yee[_1_]
February 14th 08, 06:16 AM
David E. Steitz
Headquarters, Washington Feb. 12, 2008
202-358-1730
Kathy Barnstorff
Langley Research Center, Hampton, Va.
757-864-9886/757-344-8511
RELEASE: 08-053
NASA KNOW-HOW HELPS ATHLETES ROCKET THROUGH WATER
HAMPTON, Va. -- When a swimsuit manufacturer wanted to create a better
fabric for competitive swimmers, it sought out some unlikely experts --
aerospace engineers at NASA's Langley Research Center in Hampton.
NASA has decades of experience in fluid dynamics and drag reduction.
However, aerospace engineers usually concentrate on the element
through which airplanes and spacecraft fly, not the liquid through
which swimmers travel. Still, some of the science is similar.
"Air and water are both what are referred to as Newtonian fluids,"
said Steve Wilkinson, a researcher at Langley's Fluid Physics and
Control Branch. "Air has different fluid properties than water,
including lower density and viscosity, but it still obeys the same
physical laws of motion."
That fact led Warnaco Inc. of New York, the U.S. licensee of the
Speedo swimwear brand, to seek use of a NASA wind tunnel at Langley
to test swimsuit fabrics that may be used by athletes in
international competitions.
"We evaluated the surface roughness effects of nearly 60 fabrics or
patterns in our small low-speed tunnel, which is perfect for this
purpose," Wilkinson said. "We were assessing which fabrics and weaves
had the lowest drag."
Reducing drag helps planes fly more efficiently, and reducing drag
helps swimmers go faster. Studies indicate viscous drag, or skin
friction, is about one-third of the total restraining force on a
swimmer. Wind tunnel tests measure the drag on the surface of the
fabrics.
Wilkinson and other NASA researchers usually spend their time studying
drag reduction for airplanes. They even have worked on drag reduction
technology for boats, including an America's Cup winner in the 1980s.
This expertise is one reason Speedo chose to work with NASA.
"This is the first time I've tested a fabric and there were some
challenges involved," said Wilkinson. "I think we've done a really
good job with the help of Speedo in coming up with a protocol that
enables us to test these fabrics with ease and precision."
The materials tested come in the form of tubes. Wilkinson stretches
the tubes over a smooth, flat aluminum plate and then secures the
edges with smooth metal rails and tape to form a precise rectangular
model shape. Wilkinson runs the material through a number of wind
speeds and, with the help of sensors, measures drag on the surface.
Under a reimbursable agreement, NASA turns the wind tunnel data over
to Speedo for their use.
"It turns out to simulate a swimmer in the water at about two meters
per second, we need to run the wind tunnel at about 28 meters per
second, which is well within its capability," Wilkinson added. "The
tests generally have shown the smoother the fabric, the lower the
drag."
Speedo International's research and development team, Aqualab, took
those results and used them to help create a new swimsuit the company
says is its most hydro-dynamically advanced to date.
Video of Speedo fabric testing will be available on the NASA
Television Video File. For downlink and scheduling information and
links to streaming video, visit:
http://www.nasa.gov/ntv
For more information about NASA and agency programs, visit:
http://www.nasa.gov
Headquarters, Washington Feb. 12, 2008
202-358-1730
Kathy Barnstorff
Langley Research Center, Hampton, Va.
757-864-9886/757-344-8511
RELEASE: 08-053
NASA KNOW-HOW HELPS ATHLETES ROCKET THROUGH WATER
HAMPTON, Va. -- When a swimsuit manufacturer wanted to create a better
fabric for competitive swimmers, it sought out some unlikely experts --
aerospace engineers at NASA's Langley Research Center in Hampton.
NASA has decades of experience in fluid dynamics and drag reduction.
However, aerospace engineers usually concentrate on the element
through which airplanes and spacecraft fly, not the liquid through
which swimmers travel. Still, some of the science is similar.
"Air and water are both what are referred to as Newtonian fluids,"
said Steve Wilkinson, a researcher at Langley's Fluid Physics and
Control Branch. "Air has different fluid properties than water,
including lower density and viscosity, but it still obeys the same
physical laws of motion."
That fact led Warnaco Inc. of New York, the U.S. licensee of the
Speedo swimwear brand, to seek use of a NASA wind tunnel at Langley
to test swimsuit fabrics that may be used by athletes in
international competitions.
"We evaluated the surface roughness effects of nearly 60 fabrics or
patterns in our small low-speed tunnel, which is perfect for this
purpose," Wilkinson said. "We were assessing which fabrics and weaves
had the lowest drag."
Reducing drag helps planes fly more efficiently, and reducing drag
helps swimmers go faster. Studies indicate viscous drag, or skin
friction, is about one-third of the total restraining force on a
swimmer. Wind tunnel tests measure the drag on the surface of the
fabrics.
Wilkinson and other NASA researchers usually spend their time studying
drag reduction for airplanes. They even have worked on drag reduction
technology for boats, including an America's Cup winner in the 1980s.
This expertise is one reason Speedo chose to work with NASA.
"This is the first time I've tested a fabric and there were some
challenges involved," said Wilkinson. "I think we've done a really
good job with the help of Speedo in coming up with a protocol that
enables us to test these fabrics with ease and precision."
The materials tested come in the form of tubes. Wilkinson stretches
the tubes over a smooth, flat aluminum plate and then secures the
edges with smooth metal rails and tape to form a precise rectangular
model shape. Wilkinson runs the material through a number of wind
speeds and, with the help of sensors, measures drag on the surface.
Under a reimbursable agreement, NASA turns the wind tunnel data over
to Speedo for their use.
"It turns out to simulate a swimmer in the water at about two meters
per second, we need to run the wind tunnel at about 28 meters per
second, which is well within its capability," Wilkinson added. "The
tests generally have shown the smoother the fabric, the lower the
drag."
Speedo International's research and development team, Aqualab, took
those results and used them to help create a new swimsuit the company
says is its most hydro-dynamically advanced to date.
Video of Speedo fabric testing will be available on the NASA
Television Video File. For downlink and scheduling information and
links to streaming video, visit:
http://www.nasa.gov/ntv
For more information about NASA and agency programs, visit:
http://www.nasa.gov