Volvo Trucks North America showed a 2.3% improvement in fuel economy through the use of four modifications to a typical highway tractor and trailer. Three of the modifications are prototype designs, while the fourth is already available on Volvo trucks.
The results were part of a two-year cooperative research effort between the United States Department of Energy and the Truck Manufacturers Association, and four of TMA's member companies.
Three devices were used for underside airflow management, said Michael Sorrells, Volvo's lead design engineer for aerodynamic development. The first was a smooth underside area on the front of its test truck, essentially an extension of the bumper made from composite material.
The second modification was a plate between the chassis rails on the space between the back of the cab and the fifth wheel, called a deck closure.
The most noticeable modification was on the trailer, where Volvo installed an air deflector that wrapped around the front and sides of the trailer bogie.
The final modification involved the use of roof and side fairing extenders already available to Volvo customers.
Truck operators could improve their fuel economy by as much as 8 percent by facilitating smooth air flow around their tractor-trailer units during highway travel, according to a new study by Mack Trucks Inc.
Results of a two-year study of truck aerodynamics demonstrated that fuel savings can be achieved by enclosing the gap between the tractor and trailer, and equipping the trailer with what are referred to as “side skirts” and a “boat tail.”