Abstract: A frame extension device for the reduction of aerodynamic drag and for improved performance of ground vehicles by increasing the pressure on the base of the vehicle by stabilizing the wake flow. The device is particularly suited for tractor-trailers utilizing a roll-up type rear door in that it does not block any part of the door opening. The device is of sufficient thickness to support the weight of an unloading device.

Abstract: A device for the reduction of aerodynamic drag and for improved performance and stability of ground vehicles by reducing the mass and velocity of the flow passing under a vehicle is described. The device is particularly suited for a tractor-trailer truck system that includes a motorized lead vehicle pulling one or more non-motorized vehicles. The device is designed to control the flow from entering the undercarriage region from the side of a trailer of a tractor-trailer truck system.

Abstract: An improved device for the reduction of aerodynamic drag and for improved performance of multiple component vehicles by reducing the pressure on the front face of the trailing vehicle or vehicle component by controlling the flow in the gap between the leading vehicle component and the trailing vehicle component. An improved device for generating a reduction in the drag force on a bluff face object moving through air. The device consist of the application of a plurality of forward extending surfaces that are positioned adjacent to one another on the forward facing surface of a bluff face object and are aligned parallel to the object center line and perpendicular to the local flow direction. The reduction in drag force results from the summation of a plurality of local reductions in drag force generated by the interaction of vortex structures emanating from the leading edges of the plurality of forward extending surfaces with the forward facing surface of a blunt face object.

Abstract: An improved method and device for the reduction of aerodynamic drag and for increased fuel economy of ground vehicles by increasing the pressure on the rear surface of the vehicle with a plurality of vortices generated along the top and side surfaces of the ground vehicle that flow in to the base wake region of the vehicle. The invention is comprised of a minimum number of small surfaces that attach to the side and top exterior surfaces of a ground vehicle. The spacing and orientation of the small surfaces, comprising the device, are dependent upon the vehicle geometry and vehicle operating conditions. The plurality of small surfaces are located forward of the vehicle base area. The plurality of adjacent small surfaces and are distributed circumferentially over the side and top surfaces of the ground vehicle.