Working under contract with the Oak Ridge National Laboratory, Bob Englar and other researchers at the Georgia Institute of Technology are helping reduce the aerodynamic drag on tractor-trailer truck by at least 35%. Englar's work involves a pneumatic systems called Circulation Control that creates lift on the trailer by blowing compressed air over curved surfaces on the trailer, smoothing airflow and decreasing drag. He also found that blowing air from the bottom of the truck has the opposite effect, multiplying downward force on the tires to improve traction and braking when needed. The system uses valves that respond to driver changes in a fraction of a second, augmenting force as needed. "The driver wouldn't have to think about how it works," says Englar. He estimates that, if applied to the entire U.S. fleet of tractor-trailers, the pneumatic system could save 1.2 billion gallons of fuel each year. For more information, contact Englar at (770) 528-3222 or e-mail gtri.gatech.edu.