Vehicle rack wind deflector and noise reduction apparatus
A wind deflector for mitigating the aerodynamic shortcomings exhibited by racks and frames mounted to vehicles. The deflector includes a front, forward facing or wind facing section that is oriented toward the direction of travel of the vehicle. The deflector modifies air flow so that effects such as vortex shedding, which causes noise and the rack to undulate, are minimized. Airflow modifiers are formed or mounted on the front or wind facing section of the wind deflector. The modifiers are compact features such as indentations or projections that interdict and alter the airflow pattern around the wind deflector. The deflector may be attached to an existing rack or a rack may be constructed to include the wind deflector as an integral feature.
1 . A noise reducing wind deflector for use with a vehicle rack mounted on a vehicle said vehicle rack having at least two elongated support bars connected by a front and rear cross bar, the wind deflector comprising: a front section that faces the direction of travel of said vehicle, said front section being sloped to lessen wind drag wherein the front section includes a flow modifier located on a leading edge of the front section and at least one aperture; a top section located at the top of the front section, said top section contoured to correspond to the shape of the top of the front cross bar of the vehicle rack; a rear section having at least one slot extending downwardly from said top section wherein said top section and rear section encompass the top and the rear of the front cross bar of the vehicle rack when said deflector plate is attached thereto; and a bottom section extending rearwardly from the leading edge of the front surface oriented to allow air to flow thereunder; at least one retaining strap that attaches to the front section and extends under the front vertical bar of the vehicle rack and is attached to the rear section to retain the wind deflector on said front bar which at least one retaining strap comprises an elongated curved member having a flanged distal end with a threaded aperture for receiving therethrough an elongated attachment member comprising a threaded bolt and a notched section at its proximal end; wherein the aperture of the front section of the wind deflector is constructed so that in the case in which the flanged distal end of the retaining strap is placed against the back of the front section so that the aperture of the front section and the aperture of the flanged distal end are aligned, the elongated attachment member can be placed therethrough thereby securing the retaining strap to the back of the front section; and wherein the at least one slot of the rear section is constructed to receive and retain the notched section of the retaining strap; and wherein as said vehicle progresses, a forward air flow over the front section of the wind deflector is altered by the flow modifier such that vortex shedding is reduced and noise resulting from the air flow is mitigated.
2 . The wind deflector according to claim 1 , wherein the flow modifier comprises a plurality of indentations formed along the leading edge of the front surface.
3 . The wind deflector of claim 2 , wherein the indentations are v-shaped.
4 . The wind deflector of claim 2 , wherein the indentations are u-shaped.
5 . The wind deflector of claim 2 wherein the indentations comprise a first section that slopes downward from the leading edge to a flat bottom section and a second section that slopes upwardly from the flat bottom surface to the leading edge.
6 . The wind deflector of claim 5 wherein a front opening of the indentation is the distance between the top of the first section and the top of the second section and is at least 1.9 inches.
7 . The wind deflector of claim 6 wherein the flat bottom section is located at least 0.37 inches below the leading edge.
8 . The wind deflector of claim 1 wherein the slope of the front section is changed by altering the angle of the front section relative to the bottom section.
9 . The wind deflector of claim 8 wherein the slope of the front section can be modified to optimize air flow over the wind deflector depending upon a design of the vehicle rack.
10 . A frame for transporting cargo mounted externally of a vehicle having improved aerodynamic performance, said frame comprising: at least two elongated support bars running parallel to the length of the vehicle; a front vertical cross bar and a rear vertical cross bar each extending between said at least two elongate support bars, wherein the said front vertical cross bar additionally comprises: a front section having at least one aperture that faces the direction of travel of said vehicle, said front section having a top that has a shape and said front section being sloped upwardly from a leading edge to the top of said vertical front cross bar and that is contoured to correspond to the shape of the top of said vertical cross bar; a rear section having at least one slot that is contoured to correspond to the shape of the top of the vertical cross bar; and a flat bottom section; at least one retaining strap that attaches to the front section and extends under the front vertical bar of the vehicle rack and is attached to the rear section to retain the wind deflector on said front bar which at least one retaining strap comprises an elongated curved member having a flanged distal end with a threaded aperture for receiving therethrough an elongated attachment member comprising a threaded bolt and a notched section at its proximal end; wherein the aperture of the front section of the wind deflector is constructed so that in the case in which the flanged distal end of the retaining strap is placed against the back of the front section so that the aperture of the front section and the aperture of the flanged distal end are aligned, the elongated attachment member can be placed therethrough thereby securing the retaining strap to the back of the front section; and wherein the at least one slot of the rear section is constructed to receive and retain the notched section of the retaining strap; and wherein the said leading edge includes a plurality of air modifying indentations shaped to change a flow of air over said vertical front cross bar and to mitigate a noise caused by the flow of air over and under said front vertical cross bar.
11 . The frame of claim 10 wherein the indentations are triangular in shape.
12 . The frame of claim 10 wherein the frame includes a first and a second upper elongated support mounted to the top of the elongated support bars.
13 . A noise reducing wind deflector for use with a vehicle rack mounted on a vehicle said vehicle rack having at least two elongated support bars connected by a front and rear cross bar, the wind deflector comprising: a front section having at least one aperture that faces the direction of travel of said vehicle, said front section having a top that has a shape and said front section being sloped upwardly from a leading edge to the top of said front cross bar and that is contoured to correspond to the shape of the top of said front cross bar; a rounded rear section having at least one slot that is contoured to correspond to the shape of the top of said front cross bar; a plurality of indentations extending away from the leading edge into the front section, opposite the direction of travel of the vehicle; a first and a second leg each extending from the bottom and top of the front section; a central support member extending between the top and bottom of the front section; at least one retaining strap that attaches to the front section and extends under the front cross bar of the vehicle rack and is attached to the rear section to retain the wind deflector on said front cross bar which at least one retaining strap comprises an elongated curved member having a flanged distal end with a threaded aperture for receiving therethrough an elongated attachment member comprising a threaded bolt and a notched section at its proximal end; wherein the aperture of the front section of the wind deflector is constructed so that in the case in which the flanged distal end of the retaining strap is placed against the back of the front section so that the aperture of the front section and the aperture of the flanged distal end are aligned, the elongated attachment member can be placed therethrough thereby securing the retaining strap to the back of the front section; and wherein the at least one slot of the rear section is constructed to receive and retain the notched section of the retaining strap; and wherein said wind deflector is mounted to the front cross bar of the vehicle rack such that as said vehicle progresses, a forward air flow over the front section of the wind deflector is altered by the indentations such that the air flow is modified and noise mitigated.
14 . The wind deflector of claim 13 wherein the wind defector is constructed from a flexible material.
15 . The wind deflector of claim 14 wherein said wind deflector is attached to the front cross by an adhesive.
16 . The wind deflector of claim 15 wherein the adhesive is applied to an underside of the legs and the central support.
17 . The wind deflector of claim 16 wherein said wind deflector is mounted to the front cross bar by placing the legs against the front cross bar and compressing the wind deflector into the front cross bar of the rack which brings the central support member in contact with the cross bar wherein the wind deflector is held thereon by the adhesive.