Drag reduction obtained by rounding vertical corners on a box-shaped ground vehicle. [Delivery vans, trucks, and motor homes]

A box-shaped ground vehicle was used to simulate the aerodynamic drag of delivery vans, trucks, and motor homes. A coast-down method was used to define the drag of this vehicle in a configuration with all square corners and a modified configuration with the four vertical corners rounded. The tests ranged in velocity from 30 miles per hour to 65 miles per hour, and Reynolds numbers ranged from 4.4 x 10/sup 6/ to 1.0 x 10/sup 7/ based on vehicle length. The modified configuration showed a reduction in aerodynamic drag of about 40 percent as compared to the square-cornered configuration.