US Patent 9340240 Drag mitigation system for tractor-trailer

Disclosed herein is a vortex-generating system for a moving object that has a trailing edge. The system includes a first blade coupled to the object and positioned proximate the trailing edge, a second blade coupled to the object, positioned proximate the trailing edge, and spaced apart from the first blade. The first and second blade cooperate to induce an outwardly directed vortical flow of air away from the trailing edge of the object.