Abstract:
A vehicle having one or more small vehicle-mounted electricity generating wind turbines located within an area of wind recirculation. The electricity generated is used to recharge vehicle batteries, partially power an auxiliary electric propulsion motor, or supply vehicle parasitic loads.

Description:
BACKGROUND OF INVENTION  
       [0001]     This invention relates to the use of one or more small vehicle-mounted wind turbines connected to one or more small generators to generate electricity for use by a vehicle when in motion. Specifically, the wind turbines are located in an area of wind recirculation in between the segments of an articulated vehicle combination, or in the aerodynamic wake behind the vehicle.  
       SUMMARY  
       [0002]     With the advent of modern Hybrid Electric Vehicles, much development has occurred in the art having to do with recapturing vehicle kinetic energy and regeneration of that energy into a useable form. The primary focus of development has been in the area of regenerative vehicle braking. Other areas of development have focused upon utilizing secondary sources of available energy, such as solar energy or wind energy.  
         [0003]     In many prior-art developments concerning the use of wind energy to provide power to Hybrid Electric Vehicles, the inventions as set forth have consumed more energy than they have produced. Specifically, they have involved vehicles having wind turbines located in the slipstream above or in front of the vehicle, or equivalently, having ducts leading from those locations to wind turbines located elsewhere on the vehicle. Because these turbines, or the ducts leading to them, were continually in the vehicle slipstream, they caused a net increase in the amount of power required to drive the vehicle to overcome air resistance. Constrained by the first law of thermodynamics, the wind turbines consumed more energy than they returned to the vehicle. The simplest model of these inventions would be a vehicle composed of a turbine, a generator, an electric motor, and wheels. The electric motor would drive the wheels to push the vehicle forward, which would cause the turbine to spin the generator in order to provide electricity to the electric motor.  
         [0004]     One or two of these inventions have had some merit, in that the turbine has had provisions to accept an air stream from vectors other than straight forward. That is to say, if the vehicle experienced a strong sidewind, the turbine was capable of capturing the component of the air stream not generated by its own motion, and converting that into useable energy. Under conditions of a strong headwind, a vehicle equipped with a wind turbine may even be able to generate enough energy from the vector component of the air stream not generated by its own motion, to overcome the resistance caused by the movement of the additional frontal area due to the turbine through that slipstream. This would be the thermodynamic equivalent of a sailboat tacking upwind.  
         [0005]     In the area of development having to do with Hybrid Electric Vehicles and regenerative braking, the focus has thus far been upon vehicles having a city or urban driving cycle. These vehicles, typically passenger vehicles and delivery vehicles, use large amounts of energy accelerating and accumulating kinetic energy, which is then lost upon braking. The objective of regenerative braking is to return a portion of that kinetic energy to storage in the form of electrical potential for subsequent use. For vehicles having a highway or long-haul driving cycle, such as line-haul trucks, the driving profile involves considerably less braking, and more expenditure of energy overcoming wind resistance.  
         [0006]     There exists an area of air movement relative to a moving vehicle that heretofore remains unexploited as a source of energy, and which presents the possibility of extracting energy from said air movement without requiring additional energy in order to move the vehicle. To an even greater degree of benefit, extracting energy from this area of air movement may even decrease the amount of energy required to move the vehicle. That area of air movement is the area of recirculation in between the segments of an articulated vehicle combination, or in the aerodynamic wake behind the vehicle.  
         [0007]     Articulated moving vehicles, such as highway tractor and semi-trailer combinations, possess a large gap between the tractor and trailer due to constraints having to do with articulation at low speeds. At high speeds, air passing over and around the vehicle recirculates within this gap. As a moving fluid exerts less pressure and as a greater velocity of relative movement occurs near the rear side of the tractor cab due to this recirculation, the net pressure differential between the forward side of the tractor portion of the vehicle and the rearward side of the tractor portion of the vehicle is increased as a result of this recirculation. Extracting energy from this recirculating air mass not only provides a source of energy, but also reduces this net pressure differential, thus reducing overall wind resistance. An additional principle in operation under this circumstance is based on the fact that this rotating air mass further disturbs the air flowing past the gap, and as a result promotes turbulent air flow relative to the vehicle, thereby increasing overall wind resistance.  
         [0008]     A similar principle operates within the wake of the moving vehicle. At that point, the airflow past the vehicle has generally deteriorated to a turbulent state, such that less steady-state recirculation is taking place. However, there is still a significant component of steady-state recirculation combined with shedding vortices. This steady-state component of recirculation again causes the exertion of less pressure by the moving fluid, resulting in an increase in pressure differential between the forward side of the moving vehicle and the rearward side of the moving vehicle. By extracting energy from the recirculating air mass, the pressure differential between the forward side of the moving vehicle and the rearward side of the moving vehicle is reduced. This again reduces overall wind resistance.  
         [0009]     In no way does the present invention claim to extract enough energy from the recirculating air mass to fully propel the vehicle. If it did, it would be a violation of the first law of thermodynamics. However, sufficient energy may be extracted from these regions of recirculation using small, strategically placed wind turbines coupled to efficient generators to generate fifty to one hundred amperes of useable electrical power. This figure assumes a recirculating wind speed of approximately twenty meters per second, a turbine diameter of approximately half a meter, and sea-level standard atmospheric conditions. The power generated may be used to supply vehicle parasitic loads, or it may be used to partially charge vehicle batteries.  
         [0010]     The multiple embodiments of the invention disclosed herein each involve the use of one or more such wind turbine driven generators in certain strategic locations, such as directly behind the cab of a highway tractor and semi-trailer combination, between the frame rails and skirts of such a vehicle, or in the wake area located behind a given vehicle. A single axial flow turbine driven generator, an array of such generators, or even a multi-stage axial flow turbine driven generator may be used.  
     
    
     DRAWINGS  
       [0011]      FIG. 1 —A side view of an articulated vehicle having a gap and an area of air recirculation therein.  
         [0012]      FIG. 2 —A side view of a vehicle having an area of air recirculation in its wake area.  
         [0013]      FIG. 3 —A view of a wind turbine coupled to an electrical generator.  
         [0014]      FIG. 4 —A view of a first embodiment of the invention.  
         [0015]      FIG. 5 —A view of a second embodiment of the invention.  
         [0016]      FIG. 6 —A view of a third embodiment of the invention.  
         [0017]      FIG. 7 —A side view of a vehicle having an area of recirculation extending through its chassis.  
         [0018]      FIG. 8 —A partial view of a fourth embodiment of the invention.  
         [0019]      FIG. 9 —A view of a fifth embodiment of the invention.  
         [0020]      FIG. 10 —A power diagram of a vehicle having a wind turbine coupled to an electrical generator. 
     
    
     DETAILED DESCRIPTION  
       [0021]     The vehicle  101  shown in  FIG. 1  has a cab  102  attached to a chassis  103 , and is adapted to pull a semi-trailer  105 , which semi-trailer  105  is partially shown.  FIG. 1  further shows airflow  106  relative to the moving vehicle  101 . Located between the cab  102  of the vehicle  101  and the semi-trailer  105  attached to the vehicle  101 , is a vehicle gap  107 , within which exists an area of air recirculation  108 .  
         [0022]     The vehicle  101  shown in  FIG. 2  has a cab  102  attached to a chassis  103 , and is provided with a cargo-carrying body section  104 . Airflow  106  is shown relative to the moving vehicle  101 , behind which vehicle  101  exists an area of recirculation  108 .  
         [0023]      FIG. 3  shows a wind turbine  109  having turbine blades  110  coupled to a generator  112  by means of a shaft  113 . The wind turbine  109  may be provided with a turbine housing  111 , within which the turbine blades  110  rotate. The wind turbine  109  is supported by a turbine mounting  115 . The generator  112  provides electrical power by means of electrical leads  114 .  
         [0024]     The vehicle  101  shown in  FIG. 4  has a cab  102  attached to a chassis  103 , similar to the vehicle  101  shown in  FIG. 1 . The vehicle  101  shown in  FIG. 4  is again adapted to pull a semi-trailer  105 , which semi-trailer  105  is partially shown.  FIG. 4  further shows the airflow  106  relative to the moving vehicle  101 , the vehicle gap  107 , and the area of air recirculation  108 . Attached to the cab  102 , and located within the area of air recirculation  108 , is a wind turbine  109  and generator  112 . By means of the wind turbine  109  and generator  112 , a portion of the energy contained within the recirculating air  108  is converted to electrical energy for use by the vehicle  101 .  
         [0025]     The vehicle  101  shown in  FIG. 5  has a cab  102  attached to a chassis  103 , and is provided with a cargo-carrying body section  104 , similar to the vehicle  101  shown in  FIG. 2 .  FIG. 5  shows the airflow  106  relative to the moving vehicle  101 , as well as an area of recirculation  108 . Attached to the cargo-carrying body section  104 , and located within the area of air recirculation  108 , is a wind turbine  109  and generator  112 . By means of the wind turbine  109  and generator  112 , a portion of the energy contained within the recirculating air  108  is converted to electrical energy for use by the vehicle  101 .  
         [0026]      FIG. 6  shows a rear view of a vehicle  101  having a cab  102  attached to a chassis  103 . Similar to the vehicle  101  in  FIG. 1 , the vehicle  101  in  FIG. 6  is adapted to pull a semi-trailer  105 , which is not shown in  FIG. 6 . Airflow  106  is shown entering the area of air recirculation  108 . An array of wind turbines  109  and generators  112  are attached to the cab  102  of vehicle  101 . By means of the wind turbines  109  and generators  112 , a portion of the energy contained within the recirculating air  108  is converted to electrical energy for use by the vehicle  101 .  
         [0027]     The vehicle  101  shown in  FIG. 7  has a cab  102  attached to a chassis  103 , and is adapted to pull a semi-trailer  105 , similar to the vehicle  101  shown in  FIG. 1 . The semi-trailer  105  is not shown in  FIG. 7 . The vehicle  101  is provided with chassis skirts  116  and deck plates  117 . Airflow  106  is shown entering an area of recirculation  108 , which area of recirculation  108  extends through the chassis  103 , passes within the area defined by the chassis skirts  116 , and flows upwards through the deck plates  117 .  
         [0028]      FIG. 8  shows a partial view of a vehicle  101 , including a partial outline view of a cab  102  attached to a chassis  103 , which chassis  103  is also partially shown. Similar to the vehicle  101  shown in  FIG. 7 , the vehicle shown in  FIG. 8  is provided with chassis skirts  116  and deck plates  117 . Wind turbines  109  and generators  112  are attached to the chassis  103 , and are located beneath the deck plates  117  and in between the chassis skirts  116 .  
         [0029]      FIG. 9  shows a rear view of a vehicle  101  having a cab  102  attached to a chassis  103 . Similar to the vehicle  101  shown in  FIG. 1 , the vehicle  101  shown in  FIG. 9  is adapted to pull a semi-trailer  105 , which is not shown in  FIG. 9 . Airflow  106  is shown entering the area of air recirculation  108 . A multi-stage wind turbine  118  is attached to the cab  102  of the vehicle  101 , which multi-stage wind turbine  118  is provided with multiple sets of turbine blades  110 . The multiple sets of turbine blades  110  rotate within the turbine housing  111  upon a shaft  113 , which shaft  113  in turn drives the generator  112 , thereby converting a portion of the energy contained within the recirculating air  108  into electrical energy for use by the vehicle  101 .  
         [0030]      FIG. 10  shows a vehicle  101  having a cab  102  attached to a chassis  103 . Similar to the vehicle  101  shown in  FIG. 1 , the vehicle  101  shown in  FIG. 10  is adapted to pull a semi-trailer  105 , which is not shown in  FIG. 10 . The vehicle  101  is provided with a wind turbine  109 , which wind turbine  109  drives a generator  112 . The vehicle  101  is further provided with an engine  119  for propulsion, which engine  119  also drives a primary generator  120 . The vehicle  101  may also be provided with an auxiliary electric motor  122  for propulsion. The vehicle  101  also possesses one or more vehicle batteries  121 , and vehicle parasitic loads  124 . A vehicle system controller  123  is connected to and manages power flow to and from each of the generator  112  driven by the wind turbine  109 , the primary generator  120  driven by the engine  119 , the vehicle batteries  121 , the auxiliary electric motor  122  if one is present, and the vehicle parasitic loads  124 , by means of a power distribution network  125 .  
         [0031]     Other permutations of the invention are possible without departing from the teachings disclosed herein, provided that the function of the invention is to generate usable electrical power by extracting wind energy from an area of recirculation between the segments of a moving vehicle, or from an area of recirculation within the wake of a moving vehicle. Other advantages to a vehicle equipped with a wind turbine driven generator within an area of recirculation may also be inherent in the invention, without having been described above.