Before Dick Perdichizzi can flip the switch to get another workday started, he has to alert the folks who run the power plant at MIT or the entire campus may go dark within seconds.
That is because Perdichizzi runs the Wright Brothers Wind Tunnel at the Massachusetts Institute of Technology, and with it, the mother of all air fans: a 2,000-horsepower electrical drive attached to massive blades twice Perdichizzi’s size. When it starts up, this machine draws 2 million watts of power, a tremendous sudden drain that requires coordinating with the power plant.
“If other heavy machinery are on at the same time,
or if many air conditioners are running on a hot day, we have to wait,” said Perdichizzi, who recalls tripping a breaker that cut power on the campus for eight hours.
Students, companies, and researchers from all over New England come to Perdichizzi to test the effect that moving air has on bicycles, boats, and tall buildings — just about anything curious minds want to expose to the forces of wind. The facility tested the aerodynamics of planes used in World War II.
It includes a control room, with the testing platform down a tunnel accessible through a heavy oval door that could belong on a submarine. The fan is located around two corners, and on a recent winter day the temperature inside matched the arctic air outside.
When the massive fan starts to turn, it is a little like standing next to an airplane turbine, with a sudden onslaught of overwhelming noise. Indeed, MIT cut back the top speed to 170 miles per hour after complaints.
“If you press the wrong button, you go from 50 to 150 miles per hour instantaneously,” said Perdichizzi, a senior instructor at MIT’s aeronautics and astronautics department. “Things that are not properly attached can break. And people can get seriously injured.”
That is one reason most experiments are designed without humans in the tunnel. School classes and other visitors get to experience the breeze — but only up to 35 miles per hour. And never on cold days: “Just imagine the wind chill this fan can generate. It will give you frostbite in minutes.”