Under-trailer air deflector

An air deflector for reducing the aerodynamic drag of the wheels of a rear wheel assembly for vehicles such as trucks and trailers and for suppressing the spraying of water by such wheels, comprising:

• an aerodynamic fairing adapted to be mounted beneath the body of a vehicle and immediately forward of a rear wheel assembly of the vehicle, said fairing including:
• top, bottom, and first and second side edges defining a generally rectangular fairing body for extending laterally completely across the body of the vehicle and for extending beyond the rear wheel assembly on each side of the vehicle;
• a continuous, contoured front fairing surface extending away from said top, bottom, and side edges and converging from said edges to an area of maximum extension located between said side edges, said front fairing surface being curved substantially symmetrically in a lateral direction about a vertical plane passing through the center line of said fairing so that a part of any impinging air is directed toward said first and second side edges and around the rear wheel assembly of a vehicle;
• said fairing surface being curved asymmetrically in a vertical direction, with said area of maximum extension being disposed above the center of said fairing so that the distance along the lower fairing surface between said area of maximum extension and said bottom edge is substantially longer than the distance along the fairing surface between said area of maximum extension and said top edge, the lower fairing surface curving laterally, downwardly and rearwardly toward said side and bottom edges and the upper fairing surface curving laterally, upwardly and rearwardly toward said side and top edges;
• and
• said fairing being adapted to extend downwardly from said vehicle body so that a portion of any impinging air is directed downwardly beneath and between the wheels of the rear wheel assembly and the remaining impinging air is directed laterally around the wheels of the rear wheel assembly to suppress water spray and to reduce the aerodynamic drag of the wheel assembly.