Abstract:
A scalable fluid-driven assembly that is uniquely configured to oscillate in the presence of fluid-flow. The assembly includes an adjustable electromechanically controlled fluidfoil. The fluidfoil is controlled to permit a consistently optimum angle of attack into the prevailing flow and to remain parallel with respect thereto.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention generally relates to capturing and storing the kinetic energy of a flowing fluid. More particularly, the present invention relates to the capture and storage of wind power and hydropower.  
         [0003]     2. Description of Related Art  
         [0004]     Windmills and wind turbines are generally well known in the art. Windmills traditionally include a plurality of blades or vanes connected to a rotatable shaft. Wind (or other fluids) act upon the blades to create an aerodynamic or hydrodynamic reaction upon the blades causing the shaft and blades to rotate about the axis of the shaft. Windmills have traditionally been employed across the world to: pump water, grind grain and crush stone. Additionally, windmills have been employed in systems that convert kinetic energy, namely wind, into electrical energy. The rotation of the blades of a windmill drives a generator, which in turn produces an electric current. For applications that require linear actuation, additional mechanical systems are required to translate the rotation of the blades into such linear motion, further complexifying a windmill&#39;s operation.  
         [0005]     Wind turbines are designed to work between certain wind speeds. The lower speed, called the ‘cut in speed’ is generally 4-5 ms −1 , as there is too little energy below this speed to overcome system losses. The ‘cut out speed’ is determined by the ability of the particular machine to withstand high wind. The ‘rated speed’ is the wind speed at which the particular machine achieves its maximum rated output. Above this speed, it may have mechanisms that maintain the output at a constant value with increasing wind speed.  
         [0006]     Windmills and wind turbines require frequent repair and maintenance. Blades can be damaged by high winds and the complex mechanisms that have been devised to accommodate for such must be frequently inspected and maintained. Additionally, while windmills and wind turbines present emission-free options to oil- and gas-fueled power plants, they have been implicated in the annual deaths of tens of thousands of birds, some of which are endangered. Besides the loss of life, repair and maintenance are necessitated as a result of a number of such avian fatalities.  
         [0007]     Hydropower plants operate similarly to harness the kinetic energy of flowing water to generate electricity. Hydropower plants generally include a dam, one or more turbines and a corresponding number of generators. Each turbine is positioned at the dam such that water flowing through the dam strikes and turns the turbine&#39;s blades. Each turbine is attached to a generator via a shaft such that rotation of the turbine turns the generator producing an electrical current. However, while wind turbines are designed to rotate orthogonal to airflow, hydropower turbines are generally designed to rotate parallel with water flow. Therefore, improvements to wind turbines are not easily translatable to hydropower turbines.  
         [0008]     Therefore, what is needed in the art is a system for capturing and storing the kinetic energy of a flowing fluid. What is further needed is such a system that is simpler in construction and provides greater efficiencies than current wind turbines and/or hydropower turbines. Additionally, what is needed is a system that requires less maintenance and repair.  
       SUMMARY OF THE INVENTION  
       [0009]     It is to the solution of the hereinabove mentioned problems to which the present invention is directed. In accordance with the present invention there is provided an adaptable flow-driven energy capture system comprising:  
         [0010]     a support mast having a first end and a second end, the support mast affixed a surface at said first end thereof;  
         [0011]     a balance beam having a first end and a second end and extending therebetween, said balance beam comprising a force arm side extending from said first end thereof in the direction of said second end and a load arm side extending from said second end thereof in the direction of said first end, said force arm side and said load arm side coterminating at a balance beam fulcrum, said balance beam pivotally attached the second end of the support mast at the balance beam fulcrum;  
         [0012]     a compensatory weight attached the load arm side of the balance beam at about the second end thereof, said compensatory weight selected to equalize the weight disposed about the balance beam fulcrum;  
         [0013]     a fluidfoil mast comprising and extending between and defining two ends thereof, said fluidfoil mast pivotally connected the force arm side of said balance beam;  
         [0014]     at least one fluidfoil pivotally attached the fluidfoil mast, said at least one fluidfoil having a leading edge and a trailing edge cooperatively defining an edge axis extending therebetween, said fluidfoil further having an orthogonally disposed longitudinal axis;  
         [0015]     an angle of attack positioner attached at each of and disposed between the at least one fluidfoil and the fluidfoil mast, said positioner moderating fluidfoil angle of attack with respect to fluid flow therepast;  
         [0016]     a vane disposed anterior the at least one fluidfoil, said vane registering fluid flow forces that are not parallel with the fluidfoil edge axis;  
         [0017]     at least one control having a support mast end and a fluidfoil support mast end, said control rod pivotally attached thereto and extending parallel the balance beam affixed to the Support Mast.  
         [0018]     It is an object of the present invention to provide a fluidfoil and associated electromechanical assembly capable of extracting energy from low to high velocity prevailing winds for the capture of such.  
         [0019]     It is further an object of the present invention to provide for the selectable control of positive and negative lift on a fluidfoil by changing fluidfoil attitude.  
         [0020]     It is another object of the present invention to provide an energy recapture device for conserving and reusing the energy forces required for controlling fluidfoil transitions from positive to negative lift related orientations.  
         [0021]     The adaptable fluid-driven system of the present invention is uniquely configured to oscillate in the presence of and orthogonal to the direction of fluid flow. Each of the at least one fluidfoil is dynamically positioned to promote a constant and optimum angle of attack.  
         [0022]     A balance beam is rotatably affixed a support mast at a fulcrum point. The balance beam comprises a force arm and a load arm with each extending from opposed ends of the balance beam and coterminating at the fulcrum. The force arm and the load arm are different lengths thereby providing the mechanical advantage that enables the oscillatory motion even in the presence of low energy fluid flow. Energy of such fluid flow is a function of the fluid density and velocity.  
         [0023]     The support mast is affixed a surface and includes a rotational portion disposed at a point along the length thereof such that the mast may rotate at a side of the rotational portion opposed the ground.  
         [0024]     A counterweight is attached to the load arm such that the weight at either side of the balance beam fulcrum is substantially equivalent. Given the unequal lengths of the force arm and the load arm, there is a mechanical advantage at the load arm end of the balance beam equal to the product of the length of the load Arm multiplied by the length of the force arm.  
         [0025]     A fluidfoil is aligned with a fluid flow by a vane attached at the load arm side of the fulcrum. Lift is created across the fluidfoil in proportion to fluid flow velocity and the characteristics of the airfoil well known to those skilled in the art of fluidfoils, such as airfoils. Control rods each extend equidistantly and parallel to the balance beam and are pivotally affixed to the support mast.  
         [0026]     A fluidfoil mast is attached to the balance beam and control rods in a like manner and extends in parallel to the support mast. This arrangement forms a dynamic rhomboid assembly that allows the fluidfoil to maintain an optimum angle of attack into fluid flow by adjusting that angle.  
         [0027]     An angle of attack positioning mechanism adjusts the fluidfoil&#39;s angle of attack to a constant positive or negative lift position thus enabling an up and down motion that produces lift in both directions and creating an energy harvesting capability from low velocity as well as high velocity fluid flows including wind and water flow.  
         [0028]     Harvested energy from the fluidfoil is transferred by the lever action of the rhomboid assembly to a connector for energy transfer to one of a variety of energy storage systems for converting the energy of the linear oscillating motion to other desired forms of energy. Such systems include generators or compressors or the like.  
         [0029]     As the fluid foil oscillates through positive and negative lift modes, the energy expended to make the transition is partially recaptured by an energy recapture device. This is a dual function device that dampens and stops the upward or downward motion of the fluidfoil as the angle of attack positioner changes the fluidfoil from a positive to a negative lift or vise versa.  
         [0030]     The transition point at which the foil changes from positive to negative lift and vice versa requires energy to be extracted from the positive upward momentum and stored as the action is stopped and turned around. An energy accumulator in conjunction with cam actions, solenoids, air compression pistons or calibrated springs is employed for this purpose. When this action is completed and the foil reverses its lift generating capability, the stored energy is transferred back to the foil by the energy releasing function of the accumulator to aid in quickly regenerating a negative lift component in the downward cycle. The same occurs in the negative to positive lift transition.  
         [0031]     For a more complete understanding of the present invention, reference is made to the following detailed description and accompanying drawings. In the drawings, like reference characters refer to like parts, in which:  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0032]      FIG. 1  is a plan view of a preferred embodiment of an adaptable flow-driven energy capture system in accordance the present invention;  
         [0033]      FIG. 2  is an elevated lateral perspective view of a balance beam and fluidfoil mast portions of an adaptable flow-driven energy capture system in accordance with a preferred embodiment of the present invention; and  
         [0034]      FIG. 3  is a side perspective view of a the preferred embodiment according to the present invention. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0035]     Referring to the drawings more particularly by reference numbers,  FIGS. 1 and 2  show an adaptable flow-driven energy capture system  10  according to the present invention. The system  10  is uniquely configurable to oscillate in the presence of and orthogonal to the direction of fluid flow (shown as ‘X’). Fluid flow may include airflow, running water, or some other fluid the properties of which fall within about the properties of water and air.  
         [0036]     The system  10  generally includes a support mast  12 , a balance beam  14 , a counterweight  16 , an angle-of-attack positioner  17  and an at least one fluidfoil  18 . The support mast  12  has a first end  20  and a second end  22 , the support mast  12  is attached to a ground  24  at said first end  20  thereof. The support mast  12  may be formed from corrosion resistant strong lightweight materials. Additionally, the material should withstand the forces associated with the reciprocating movement of the balance beam  14  resulting from movement of the at least one fluidfoil  18 . Aluminum, titanium, composite or some other material well known to one skilled in the art may be used.  
         [0037]     The balance beam  14  has a first end  30  and a second end  32  and extends therebetween. The balance beam  14  is preferably formed from a strong, lightweight material that resists corrosion. Such materials are well known in the art and include aluminum, titanium, or some other material well known for such properties. The balance beam  14  comprises a force arm side  34  extending from said first end  30  thereof in the direction of said second end  32  and a load arm side  36  extending from said second end  32  thereof in the direction of said first end  30 , said force arm side  34  and load arm side  36  each coterminate at a balance beam fulcrum  38 . The balance beam  14  is pivotally and rotatably attached at the second end  22  of the support mast  12  at the balance beam fulcrum  38 .  
         [0038]     The force arm side  34  and the load arm side  36  are different lengths. More particularly, the load arm side  36  of the balance beam  14  is longer than the load arm side  34  providing a mechanical advantage at the force arm side  34  of the balance beam. As discussed further hereinbelow, by configuring the relative lengths of the force arm side  34  and the load arm side  36 , one is able to configure the system  10  depending upon the conditions under which the system is operating.  
         [0039]     As shown in  FIG. 3 , the support mast  12  houses a bearing  50  to which is affixed a support masthead  53  that extends coaxially and rotates about a longitudinal axis of the support mast  12 . Force sensing means  55  sense rotational forces at the bearing  50  and precludes rotation of the support masthead  53 . Such force sensors are known to those skilled in the art and as such shall not be further discussed herein. The support masthead  53  is preferably formed from materials known to those skilled in the art to function similarly to those comprising the balance beam  14  and the support mast  12 .  
         [0040]     The counterweight  16  is attached the load arm side  36  of the balance beam  14  at the second end  32 . The counterweight  16  is selected to equalize the weight at either side of the fulcrum  38 . The means for attaching the counterweight  16  preferably provide for removably attaching the counterweight  16  such as clamping or bolting, or some other means for removable attachment well known to those skilled in the art. The unequal lengths of the force arm side  34  and the load arm side  36  create a mechanical advantage at the load arm end of the balance beam.  
         [0041]     A fluidfoil mast  40  has a first end  42  and a second end  44  and extends therebetween. The fluidfoil mast  40  is pivotally connected at the force arm side  30  of the balance beam  14 . Each at least one fluidfoil  18  is pivotally attached the fluidfoil mast  40  at a fluidfoil pivot point  22 . The fluidfoil mast  40  additionally comprises a center section  45  having two opposed ends  49 ,  51 . End sections  53 ,  55  are rotatably attached one at each end  49 ,  51  through a motor or some other well-known means for rotating  71  one element relative another. In this fashion, each of the at least one fluid foils  18  can be rotated about the longitudinal axis of the foil support mast  40  as described hereinbelow in greater detail.  
         [0042]     Each fluidfoil  18  comprises a leading edge  50  and a trailing edge  52  that define an edge axis (Y) extending therebetween. As most easily viewed in  FIG. 2 , each at least one fluidfoil  18  further defines a longitudinal axis (Z). While the system  10  will function with at least one fluidfoil  18  as disclosed, it is to be appreciated that the at least one fluidfoil  18  in the preferred embodiment comprises two substantially identical airfoils  26 ,  26 .  
         [0043]     Lift is created across the at least one fluidfoil  18  in proportion to fluid flow velocity and characteristics of the fluidfoil  18  well known to those skilled in the art of fluidfoils, including airfoils. Control rods  70 ,  72  each extend preferably equidistantly and parallel to the balance beam  14  and are pivotally affixed to the support masthead  52  and the fluidfoil mast  40  respectively via well-known pivotal mounting means. This arrangement forms a dynamic rhomboid assembly that allows the fluidfoil  18  to maintain an optimum angle of attack into fluid flow by restricting the travel of the fluidfoil mast  40  to remain perpendicular to the ground  24 .  
         [0044]     The angle of attack positioner  17  is attached at each of and disposed between the at least one fluidfoil  18  and the fluidfoil mast  40 . By pivoting the at least one fluidfoil  18  about pivot point  22 , the angle of attack positioner  17  moderates the at least one fluidfoil&#39;s  18  angle of attack with respect to fluid flow X therepast. As such, each of the at least one fluidfoil  18  is alternatingly positioned to maintain the angle of attack at a generally constant positive or negative lift position depending upon the direction of travel of the balance beam. Sensing means  80 , such as an optical encoder, potentiometer or other well-known rotational sensors is preferably disposed about the fulcrum.  
         [0045]     When the foil reaches the top/bottom of travel as indicated by the position indicated by the sensing means  80 , the angle of attack positioner  17  is activated to reverse the angle of attack. As such, given the configuration of the preferred embodiment, the angle of attack positioner is configured to receive such control signals. Varying the angle of attack enables the reciprocating up and down motion that produces lift in both directions and facilitates energy harvesting from low velocity as well as high velocity fluid flows. Note that the terms ‘up’ and ‘down’ are with respect to the defined ground  24 .  
         [0046]     While fluid flow velocity is within a predetermined range, the positioner  17  maintains the fluidfoil  18  at an optimum angle of attack to provide maximum lift. When fluid flow exceeds such a range, positioner  17  alters the angle of attack, effectively reducing lift to guard against damaging the system  10 . A wind meter, such as the WindMate wind meter produced by SpeedTech, Inc., located in Great Falls, Va. 22066, can be housed within one of the at least one fluidfoil  18  to measure wind speed. Such information is used to adjust the angle of attack at times when wind speeds exceed a selected threshold. Wind meters are well known to those skilled in the art and as such shall not be discussed further herein.  
         [0047]     As the at least one fluidfoil  18  oscillates through positive and negative lift modes, the energy expended to make the transition between such is partially recaptured by an energy recapture device  61 . The energy recapture device  61  dampens and stops the upward or downward motion of the at least one fluidfoil  18  as the angle of attack positioner  17  changes the fluidfoil from a positive to a negative lift or vise versa.  
         [0048]     A transition point at which the fluidfoil  18  changes from positive to negative lift and vice versa requires energy to be extracted from the travel momentum and stored as the action is stopped and turned around. An energy accumulator in conjunction with cam actions, solenoids, air compression pistons or calibrated springs is employed for this purpose. Such devices and their function with regard to reciprocating motion are well known in the art. As the fluidfoil reaches it&#39;s maximum travel, the energy recapture device  61  drives the movement of the balance beam  14  in the opposite direction from that it was traveling. To aid in quickly regenerating a negative lift component in the downward cycle. The same occurs in the negative to positive lift transition.  
         [0049]     A vane  60  is attached anterior the at least one fluid foil  18 . Preferably the vane is positioned at the second end  32  of the balance beam  14 . The vane  60  is configured so that fluid flow incident thereto serves to apply rotational force at the force sensing means  55  at the bearing  50 . The rotational force, or torque, at the bearing  50  is communicated to the means for rotating  71  at the end sections  53 ,  55  to rotate the at least one fluidfoil  18  in response to the sensed torque. As such, no rotation takes place at the bearing  50 .  
         [0050]     The vane  60  is attached to the balance beam  14  via well-known mounting means including brackets, or bolts and is preferably removably mounted to ease in repair or replacement if such is required. Alternatively, the vane  60  may be permanently affixed by welding or some other well-known means for permanent attachment. Additionally, the vane  60  is preferably formed from a lightweight corrosion-resistant material consistent with the other elements of the preferred embodiment of the present invention.  
         [0051]     Harvested energy from the fluidfoil is transferred by the lever action of the rhomboid assembly to a connector  80  for energy transfer to one of a variety of energy storage systems for converting the energy of the linear oscillating motion to other desired forms of energy. Such systems include, for example electrical generators. Alternatively, the connector  80  may drive a compressor  82  for compressing air.  
         [0052]     While certain exemplary embodiments of the present invention have been described and shown on the accompanying drawings, it is to be understood that such embodiments are merely illustrative of and not restrictive on the broad invention, and that this invention not be limited to the specific constructions and arrangements shown and described, since various other modifications may occur to those ordinarily skilled in the art. As such, what is claimed is: