300-feet-long wind tunnel is largest of its type in the world

WASHINGTON - A 300 feet long wind tunnel that is the largest of its type in the world is situated at the University of New Hampshire.

The new Flow Physics Facility (FPF) is the world’s largest scientific quality boundary-layer wind tunnel facility.

It will help engineers and scientists better understand the dynamics of turbulent boundary layers, informing the aerodynamics of situations such as atmospheric wind over the ocean, the flow of air over a commercial airplane or of seawater over a submarine.

Two 400-horsepower fans, each moving 250,000 cubic feet of air per minute, can generate a wind of approximately 28 miles per hour in the facility.

The relatively low velocity of wind generated over a great distance makes for greater accuracy in measuring the turbulence that develops in a specific class of flows known as high Reynolds number flows.

“The philosophy behind this facility is the big and slow approach,” said Joe Klewicki of the Center for Fluid Physics.

Martin Wosnik, who helped design the facility with Klewicki said, “Turbulence is often called the last unsolved problem in classical physics, and our lack of understanding has many adverse effects, from weather prediction to engineering design and practice.”

The wind tunnel is also ideally suited for human-scale aerodynamic studies, said Klewicki. By positioning athletes like skiers or bicyclists in the tunnel, scientists and coaches could improve helmet design, posture, or pedaling position for maximum efficiency.

For elite competitors, “the smallest change in where your knee is when you pedal, for instance, can mean the difference between finishing first or fifth,” said Klewicki.

The FPF, which is on Waterworks Road on the eastern edge of campus, is essentially a rectangular box, 300 feet long by 20 feet wide. The fans create suction that pulls air through open garage-style doors on the opposite end of the facility: “Unless both garage doors are open, the fans won’t run. Without such precautions one could cause damage to the structure,” said Klewicki.

Other features of the facility, which cost 3 million dollars, are a 10-inch-thick poured concrete floor; moisture-proof walls; windows designed to accommodate laser measurement from the outside; a turntable; and drag plates on the floor for measuring aerodynamic force, as on an airplane. (ANI)