Pneumatic Aerodynamic Control And Drag-reduction System For Ground Vehicles

Abstract

A blowing system for controlling the aerodynamics of a ground vehicle comprises a source of compressed air, a valve for regulating the flow of the compressed air, and a plenum for discharging the air at a rear portion of the vehicle. The air discharged through the plenum prevents flow separation and consequently reduces the drag on the vehicle. It may also increase lift, reducing effective weight and thus rolling resistance of the tires, or decrease lift to improve tire traction and handling. The blowing system may have separate plenums for the left and right sides of the vehicle whereby vortex roll-up and flow separation which occur on only one side of the vehicle may be eliminated. Asymmetrical blowing of only one plenum will produce rolling and yawing moments to restore the vehicle's lateral/directional stability when exposed to a side wind. Further, the blowing system may have a lower plenum for reattaching flow, generating a negative lift or download to increase traction, braking, and handling and for generating pitch trim. The blowing system may have a number of sensors for detecting various conditions, such as the direction and pressure of a relative wind, turbulence at the rear of the vehicle, braking, or angle of steering. The blowing system may be responsive to one or more of these conditions to selectively adjust the aerodynamics of the vehicle.