Navistar has teamed up with Lawrence Livermore National Laboratory, NASA's Ames Research Center and the U.S. Air Force to develop and test devices for reducing the aerodynamic drag of heavy-duty trucks.

Lawrence Livermore is currently conducting a full-scale test in the wind tunnel at the National Full-Scale Aerodynamics Complex, which operates under the direction of the Arnold Engineering Development Center, located at Ames. The project is aimed at identifying drag reduction devices, both commercially available and still under development that show the potential for improving fuel efficiency. The wind tunnel is 80 feet by 120 feet, more than enough to hold a 53-foot trailer.

Using 30 years of semi-truck aerodynamic research and development as well as computer simulation, the Lawrence Livermore lab has identified critical drag producing regions around trucks, such as the trailer base, underbody and the gap between the tractor and trailer. LLNL scientists believe that by placing aerodynamic devices in these regions, the trucking industry could see as much as a 12 percent increase in the fuel efficiency rate, which annually saves 3.4 billion gallons of diesel fuel.

"This is a technology that could easily be installed on the tractor trailer trucks that are out on the highway today," said Kambiz Salari, LLNL's lead scientist on the project. "And 12 percent is just the beginning. We expect to increase that savings even more during the current series of wind tunnel tests."

The commercially available devices to be tested are manufactured by Aerofficient, Aeroindustries, AT Dynamics, Freightwing, Laydon Composites and Windyne.

Prototype devices currently under development will be provided by LLNL and Navistar, which are collaborating to get proven drag reduction devices on the road. Device performance will be evaluated under different tractor-trailer combinations.

"Making our trucks more fuel efficient means we not only travel further using less fuel, but it means we can get our goods to the general public in a more timely, and ultimately, less expensive way," said Ron Schoon, chief engineer of aerodynamics at Navistar.