04-27-05

Iowa State University's big, powerful and $1.25 million wind tunnel starts blowing

AMES, Iowa -- Walk inside Iowa State University's new wind tunnel and check out the 9-foot fan attached to a 350-horsepower engine. Look at the gusting mechanism. See the vanes that help powerful winds turn the rectangular tunnel's four corners. Eye the funnel that accelerates those winds up to 110 mph through the testing chambers.

Partha Sarkar, an associate professor of aerospace and civil engineering and the director of Iowa State's Wind Simulation and Testing Laboratory, and Fred Haan, an assistant professor of aerospace engineering, are testing and calibrating Iowa State's $1.25 million Aerodynamic/Atmospheric Boundary Layer Wind and Gust Tunnel. (It's called AABL for short and pronounced "Able.")

Research in the new wind tunnel could lead to improvements in a corn plant's ability to stand up to high winds, buildings that are safer in high winds and semi trucks that handle better in a crosswind. Or, companies could pay for time in the wind tunnel to see if their products can stand up to high winds and gusts.

The wind tunnel, built on the second floor of Howe Hall overlooking Iowa State's tornado simulator, has several unique features:

• Two test sections. The aerodynamic section is 8 feet wide and 6 feet high. It can handle wind speeds up to 110 mph and is good for aeronautical and mechanical engineering applications. The atmospheric boundary layer section (which simulates winds near the ground) is 8 feet wide and 7.25 feet high. It can handle wind speeds up to 85 mph and is good for civil and environmental engineering applications.
• A gust generator. The generator works independent of the fan speed and can almost instantly increase mean wind speeds by 25 percent.
• Closed- and open-circuit capabilities. When run as a closed circuit, the wind tunnel is closed to outside air and wind runs laps through the tunnel's 270 feet. As an open circuit, the ends of the wind tunnel are opened and air is continually drawn in and blown out the U-shaped circuit.

Sarkar said the only school in the Midwest with a larger wind tunnel and a higher wind speed is Wichita State University in Kansas. Wichita is also home to a Boeing aircraft manufacturing plant.

"This is a big, powerful and versatile wind tunnel for both wind engineering applications requiring atmospheric boundary layer wind and basic aerodynamic applications requiring low-turbulence wind," Sarkar said. "We have built something special and unique for research, education and industrial applications."

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