CROSS-REFERENCES TO RELATED APPLICATIONS
Not applicable.
STATEMENT REGARDING FEDERALLY-SPONSORED RESEARCH OR DEVELOPMENT
Not applicable.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a system and method for producing electricity from the movement of a vehicle. More specifically, the present invention makes use of the aerodynamic drag created by the movement of a vehicle through a fluid medium and converts that drag into electrical energy.
2. Description of the Related Art.
Aerodynamic drag is the fluid drag force that acts on any moving solid body in the direction of the fluid freestream flow. From the solid body's perspective, the drag comes from forces due to pressure distributions over the body surface and forces due to skin friction, which is a result of viscosity of the fluid.
Aerodynamic drag is present in any system in which a solid body is in movement relative to the fluid, such as in the case of the movement of vehicles (e.g., a car or airplane) being propelled along a roadway or through air. The force may be used to create mechanical work that can subsequently be converted to electrical energy.
SUMMARY OF THE INVENTION
The present invention provides a system for harnessing energy created by a region of aerodynamic drag of a moving vehicle. The system comprising at least one traveling surface (such as a road or runway) having an intended direction of travel, and at least one turbine assembly having a shaft, a plurality of air-engaging members fixed to the shaft, and an axis of rotation concentrically aligned with the shaft. The turbine assembly is positioned proximal to the at least one traveling surface to intersect the region of aerodynamic drag created by the moving vehicle.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1-2 show an embodiment of the system in use at an airport.
FIGS. 3-4 show a second embodiment of the system in use along a section of roadway.
DESCRIPTION OF THE INVENTION
FIG. 1 shows an embodiment of the present invention in use at an airport. A runway 20 built on a ground surface 22, which runway extends in a first direction to provide a path for arriving and departing airplanes. A turbine assembly 24 is positioned proximal to one end of the runway 20. The turbine assembly 24 includes a shaft 26 with a horizontal axis of rotation 28 and a plurality of air-engaging members 30 (e.g., blades). The shaft 26 is connected to an electrical generator 32. Although only one turbine assembly 24 is shown, alternative embodiments of the system anticipate the use of a plurality of turbine assemblies located proximal to the end of the runway 20.
Although the turbine assembly 24 shown in FIG. 1 comprise blades 30, such as those found in Darrieus-style turbines, alternative embodiments contemplate turbines having a plurality of scoops, such as those in used with Savonius-type turbines. Moreover, although the turbine assembly 24 shown in FIG. 1 is horizontal-axis turbines, alternative embodiments contemplate the use of vertical axis turbines.
Still referring to FIG. 1, an airplane 34 is shown moving in the first direction and descending in elevation relative to the runway 20 in anticipation of landing. As the airplane 34 moves through the air, regions 36 of aerodynamic drag are created behind the airplane 34. As the airplane 34 passes over, but proximal to, the turbine assembly 24 while landing, the aerodynamic drag regions 36 intersects with the blades 30 and exert a rotational force on the shaft 26, causing the shaft 26 to rotate in a first rotational direction RD 1. This rotation causes the generator 32 to create electricity, which may be transferred to an on-site electrical storage bank or provided to a power grid.
As shown in FIG. 2, after the airplane 34 touches down on, and travels along, the runway 20, the aerodymanic drag regions 36, while decreasing in volume with the decreasing speed of the airplane 34, exert force on a plurality of turbine assemblies 24 positioned on either side of the runway 20, causing rotation of the shafts 26 of the turbine assemblies 24 in the first rotational direction RD1 and the subsequent generation of electricity by the associated generators 32. In an alternative embodiment, a turbine assembly may also be positioned at the second end (not shown) of the runway 20 to harness the energy of the aerodynamic drag of a departing airplane.
FIG. 3 shows an alternative embodiment of the present invention, which comprises a plurality of vertical-axis turbine assemblies 38, each with a vertical axis of rotation 40, positioned between two opposing travel surfaces 42 (e.g., a road median 44), which are shown as highways built on a ground surface 46. Each of the turbine assemblies 38 are identical to the turbine assemblies 24 shown in FIGS. 1-2 except they are vertically oriented. In this embodiment, the turbine assemblies 38 comprise a plurality of inferior, or lower, turbine assemblies 48 and an aligned plurality of superior, or upper, turbine assemblies 50.
FIG. 3 further shows the roadways 42 in use by a typical personal vehicle, such as a sport utility vehicle (SUV) 52. The SUV 52 travels along the roadway 42 in a first direction, creating a region 54 of aerodynamic drag behind it. The region 54 of drag exerts its force on each of the lower turbine assemblies 48 as the SUV 52 moves along the roadway 42, causing the shafts of the lower turbine assemblies 48 to rotate and cause generation of electricity. The generated electricity may then be stored in local power storage cells or transmitted remotely to a transmission grid. Because of the profile of the SUV 52, the drag region 54 does not intersect the upper turbine assemblies 50, resulting in more efficient generation of electricity.
FIG. 4 depicts a tractor-trailer 56 traversing the roadway 42 in the first direction, which creates a second region 58 of aerodynamic drag larger than the first region 54 shown in FIG. 3 because of the larger aerodynamic profile of the tractor-trailer 56 relative to the SUV 52. The second region 58 of drag operates on the both the lower and upper turbine assemblies 48, 50.
The present invention is described in terms of preferred embodiments in which a specific system and method are described. Those skilled in the art will recognize that alternative embodiments of such system, and alternative applications of the method, can be used in carrying out the present invention. Other aspects and advantages of the present invention may be obtained from a study of this disclosure and the drawings, along with the appended claims. Moreover, the recited order of the steps of the method described herein is not meant to limit the order in which those steps may be performed.