The present invention is directed to a wind generator system having a biomimetic aerodynamic element for use in improving the efficiency of the wind generator system.
In recent years the need for alternative sources of electrical energy has grown significantly as a result of increased and uncertainty in oil prices, environmental concerns, and the lack of sufficient alternative energy supplies. Accordingly, wind generator systems have gained support as an alternate energy source. Wind generator systems have been shown to provide a safe and clean source of electric power. Systems, such as large or big wind generator systems, have been developed having large blades (often more that 18 feet in length) mounted on high towers that can produce more than 35 kilowatts (kW) of power with wind speeds of 20 knots. Such systems are typically used in combination with other wind generator systems, such as along coastal areas for providing electrical power directly to power grids and have also been used in rural areas, such as farms, for providing supplemental power or reducing electrical costs.
Small wind generator systems mounted on smaller towers have been developed for use such as for residential application and have been used as remote or distributed power sources. Such systems are often connected to the main electric service to the home thereby allowing sufficient powering of the home and for sending excess power generated by the wind generator back to the power grid. Typically, theses small wind generators systems have blades that rotate at speeds that vary with wind speed and are connected to a rotor coupled to a gearbox that operates to increase the rotation speed of a generator producing electric power.
In operation, wind generator systems operate by converting kinetic energy of the wind into rotational energy of the rotor and drive shaft which is then converted into electrical energy by a generator coupled to the drive shaft. Accordingly, a primary objective in wind generator design is to maximize aerodynamic efficiency (the efficiency that power is obtained from the wind) of the system. This aerodynamic efficiency, such as the efficiency of the bladed hub or rotor, is dependent on a number of variables which include the number of blade attached to the hub, the shape and orientation of the blades, the pitch angle of the blades, and the length of the blades.
The theoretical maximum power efficiency of any type of a wind turbine operating in an open atmosphere is Ce=0.59 (fifty-nine percent) or the Betz Limit. However, current propeller or horizontal wind axis turbines are considerably lower at 0.32-0.45 (thirty-two percent to forty-five percent) with only ten to thirty percent of the power of the wind actually converted into usable electricity by horizontal axis wind turbines (HAWT). Both types of vertical axis wind turbines (Darius and Savonius) offer 0.18-0.28 (eighteen percent to twenty-eight percent). This is not necessarily an issue in that the majority of HAWT's are used within utility operated wind farms whereby the generated electricity is subject to an 80% (eighty percent) during transmission. Whereas vertical axis wind turbines (VAWT) are used locally whereby their efficiencies are not as a significant issue.
In the last decade several studies have determined that the grouping of VAWTs of either Darius or Savonius type will provide improvement of efficiencies. These groupings are based on vortex generation observed in schooling fish. Such vortices may be optimized through the placement of the VAWT's or VAWT towers. These VAWT wind farms or smaller wind gardens offer efficiencies higher than that of HAWT towers with greater reliability.
In developing designs for other aerodynamic components, such as aircraft wings, birds have often been studied and numerous fixed and variable airfoil profiles have been developed that were inspired by birds in an attempt to optimize lift while minimizing drag. While large birds and birds of prey have wing structures such as hooks and twists to increase lift over a broad range of airspeeds efficiently, such aerodynamic structures have not been effectively utilized in structures such as wind generator systems.
Accordingly, it would be desirable to have a wind generator system having a plurality of rotating blades, wherein each blade has improved lift and drag characteristics over prior art blades, that do not significantly increase the cost of the wind generator system or decreases the reliability of the system, that is acoustically and aesthetically acceptable for residential operation, and which is relatively inexpensive to manufacture and install.
The present invention is a new and novel wind generator system having one or more blades each having a biomimetic aerodynamic element that operates to harness wind energy effectively. In a preferred embodiment of the invention, the biomimetic aerodynamic element comprises a rotor having a plurality of blades attached to the rotor and extending radially outwardly therefrom. Each blade includes a first portion having a distal end for attaching to the rotor and a proximal end attached to a scoop portion with individual scoop sections each individual scoop section having an angle of incidence to the wind that increases the lift of the blade (increasing the rotational force on the rotor) while decreasing drag.
In another preferred embodiment of the invention wherein the angle of incidence of each scoop section is varied to create a hook and a twist along the scoop portion.
In another preferred embodiment of the invention the wind generator system operates to convert wind energy into electrical energy, the system having at least one rotor and at least one blade attached to the rotor and extending radially outwardly therefrom. Each blade includes a first portion having distal end for attaching to the rotor and a proximal end attached to a scoop portion, wherein the scoop portion includes individual scoop sections each having an angle of incidence to the wind that increases the lift of the blade (increasing the rotational force on the rotor) while decreasing drag.
In another preferred embodiment of the invention the wind generator system operates to convert energy from wind into mechanical energy for operating a mechanical system.
In another preferred embodiment of the invention wherein each individual blade of the wind generator system comprises an aerodynamic adjustment element for adjusting the aerodynamic characteristic of the blade.
In another preferred embodiment of the invention each individual blade of the wind generator system comprises an aerodynamic adjustment element for adjusting the aerodynamic characteristic of scoop portion the blade.
In a preferred embodiment of the invention the aerodynamic element is a thin film material.
In another preferred embodiment of the invention the aerodynamic element is a metallic composite coating.
In another preferred embodiment of the invention the aerodynamic element is formed from a shaped memory material or a functional material.
In another preferred embodiment of the invention the shaped memory alloy is Nitinol.
These and other features, aspects, and advantages of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings.
To provide a more complete understanding of the present invention and further features and advantages thereof, reference is now made to the following description taken in conjunction with the accompanying drawings, in which:
The present invention relates to low or small wind generator systems. In describing the preferred embodiments of the invention illustrated in the drawings, specific terminology will be resorted to for the sake of clarity. However, the invention is not intended to be limited to the specific terms so selected, and it is to be understood that each specific term includes all technical equivalents that operate in a similar manner to accomplish a similar purpose. As used herein the terms “upper” or “upwardly” refer to the direction away from the ground. The terms “lower” or “downwardly” refer to the direction towards the ground. The term “ground” refers to the surface that the wind generator system is resting on, such as the earth, or a support structure.
The present invention is a new and novel wind generator system having one or more vertical axis blades that utilize a biomimetic aerodynamic elements, such as angular system of scoops, that creates a geometry similar to that of a raptor wing where the wing from the terminal root at the fercular junction radiating to the wing tip whose feathers induce a hook. It is this hook geometry that is translated to the geometry of this novel scoop design. The leading-edge slat in avian wings functions as a spoiler as it operates to increase lift. This avian leading-edge slat does not cover the entire leading edge and creates a hook in raptors that provides a high-lift component at high-angles of attack where the avian wing structure is nearly equivalent to the rotor of the subject invention. Further, the slotted design of the scoops imitates the slotted wingtips common to soaring birds and operate to improve lift and to reduce induced drag. It has been found that such wings reveal novel passive aerodynamic mechanisms reducing flow separation and improved capture of all wind components. Further, the biomimetic system of the subject invention creates an aerodynamic system that functions to optimize lift over a range of wind velocities while reducing drag on the rear of the rotors in rotation as the blades advance to the center line of the wind. The center line of air flow over the novel biomimetic blades is the axis or center shaft. The fixed geometry and passive structure of the rotors of the subject invention operates to reduce the requirement for moving components and effectively captures the lift component while reducing drag thereby exploiting the structural reliability of a vertical axis wind generator of Savonius type while improving lift and decreasing drag. It will be understood that when forces and velocities are at equilibrium, the subject invention optimizes the scoop angles which are inclined forward and the scoops and scoop angles exhibit lift and drag that are parallel and perpendicular to the rotors. Prior to reaching equilibrium of wind velocity, the lift on the upper scoop, just as with a raptor wing hook, is predominately vertical and produces significant improvement over a flat Savonius scoop.
The idea of increasing lift in a vertical axis wing generator or turbine (VAWT) is not itself new. Devices have been developed including ducting and composite rotors. While these devices do have some impact on lift, the increased complexity of the designs create complex and expensive manufacturing and maintenance procedures and ultimately decrease reliability making them unsuitable for many applications. The subject invention provides a new and novel design for VAWTs that reduces drag while maintaining reliability and simplicity in manufacturing. The ability to maintain simplicity in rotor design in VAWTs cannot be overstated, as their reliability and simplicity of manufacture and operation are critical to their application. The novel design of the subject application maintains these characteristics and offers significant advantages in performance and operations.
All aerodynamic surfaces have vertical and horizontal lift components. Exploiting the horizontal lift component in a VAWT rotor of the subject invention results un reducing drag on the advancing blade while increasing lift at the receding blade. This also induces a vortex in a three or more plurality of blades thereby decreasing the stagnation pressures to the rear of the rotors and at equilibrium and at higher wind speed it also creates a vacuum effect on the blunt rear skinned area of the rotor thereby increasing efficiency further. In the teachings of avian wing anatomy and geometry, it is observed that certain species, such as raptors, induce a hook like structure at the upper tip of the out wing which is referred to as a hook. This hook has several analogies in aerodynamics and aerodynamic control surfaces. The most common type of high-lift devices is a flap. One type of flap is a split flap, which is utilized in the subject invention, which operates to increase lift area of the inner rotor scoop or trough and limits vortices in the captured airflow. As many VAWTs depend on turbulent boundary layers, this in a novel aspect of the subject invention and operates to increase efficiency without the common brute force methodology. High-lift aerodynamic devices, such as flaps, operate by changing the geometries of aerodynamic surfaces through changes in camber or curvature of lifting surfaces such as wings and rotors. These devices specifically change the primary air stream facing elements of wings and rotors on the leading and trailing edges as well as the tips and roots. For the nearly slab sided Savonius wind turbine rotor and devices that provide the greatest lift improvements are those that allow for a novel geometry in the capture and direction of air flow or wind and the force imparted to the rotor. It will be clear that another novel element of the subject invention is the use of a single disk or plate attached to the top of the rotor frames. The use of such a disk or plate operates to increase the effectiveness of the flap and slat type lifting devices and functions as a lifting device itself. The disk or plate also operates to reduce weight of rotor frames and acts as a wind guest support thereby preventing buckling of the rotor frame or spiders thereby increasing reliability. Further, in a preferred embodiment of the subject invention, the rotor is a vertical rotor with a skin or web that directs the wind into the scoop or trough at the outer region of the rotor. In another preferred embodiment of the invention, the scoop or trough includes a fixed aerodynamic high-lift device, such as a slat or flap, that operates to capture the wind and redirects it to the upper scoop or trough area thereby increasing horizontal lift on the rotor. In another preferred embodiment of the invention, the rotor includes a flat skinned or webbed area connecting the rotor frame root with the outer scoop or trough. This flat area includes slotted areas that increases airflow on advancing blades through mechanical flaps reducing drag. In another preferred embodiment of the invention, the web or flat skin area of the rotors include slotted devices that employ a ridge in the slot flap that supports reduction in turbulence on the face of the rotor skin or eb region and redirects the air flow to the scoop or trough thereby improving capture within the high-lift portion of the rotor.
Referring to
Referring to
Referring to
Preferably, as stated above, the aerodynamic adjustment element 130 may be in other forms such as embedded wire, thin film or a metallic coating. Referring to
It should also be apparent that in another preferred embodiment of the invention the aerodynamic adjustment element can be used to adjust the aerodynamic characteristics of the blades and/or the scoop portion of the blade to allow them to accommodate the high wind speed. It should be apparent that unlike many prior art systems, the wind generator system of the subject application can operate under a variety of wind conditions from small (low) wind to high wind conditions.
It should now be understood that the integration of biomimetic devices in a rotor increases the efficiency of VAWTs while maintaining structural strength, reliability and relatively low noise emissions is a significant challenge. The conventional type of rotor provides a simple single angle of incidence, simple arc scoop at the outer approximate third of the rotor to capture airflow generated by wind. The use of biomimetic devices such as wing hooks and twists to increase lift and decrease drag on the vertical axis rotors particularly Savonius type turbine offers unique accommodation to maintaining the advantages mechanically and in terms of safety and reliability over that of horizontal axis wind turbines or propeller systems. These biomimetic devices create a substantial different geometry from that of the conventional rotor. The biomimetic devices of the subject invention create a varied geometry along the height of the rotor scoop allowing for change of the angle of incidence of the scoop section from the bottom to the top of the scoop. This change of the angle of incidence to the wind of the individual scoop sections increases lift at the top and establishes a top hook and a twist through the adjacent section to the outer edge of the rotor scoop. The angle of incidence to the airflow of the wind is varied from the top to the bottom of the rotor through the scoop section inducing a geometry imitating that of a hook and twist on the wing of a bird or raptor. Thus, increasing the horizontal and vertical lift components whereby increasing force on the rotor and torque of the turbine. This effectively reduces drag on the advancing rotors.
Referring to
Referring to
In another preferred embodiment, as illustrated in
Accordingly, the subject invention is directed to a wind generator system for generating electrical power from wind, the wind generator system comprising a rotor, a drive shaft connected to the rotor and to a generator for converting mechanical energy into electrical energy; and a plurality of blades attached to the rotor and extending radially outwardly therefrom. In a preferred embodiment each blade includes a first portion having a distal end for attaching to the rotor and a proximal end attached to a scoop portion with individual scoop sections. Each individual scoop section has an angle of incidence to the wind that operates to increase the lift of the blade while decreasing drag. In a preferred embodiment, each said scoop portion creates a hook and a twist such that the angle of incidence to the wind for each scoop section is varied along the scoop portion. In another preferred embodiment of the invention, the generator system includes an aerodynamic adjustment element operates to automatically adjust the aerodynamic characteristics of each blade by adjusting the aerodynamic characteristics of the scoop portion of each blade. In a preferred embodiment, the angle of incidence of each scoop section is varied to create a hook and a twist along the scoop portion. In a preferred embodiment, the aerodynamic adjustment element operates to automatically expand or contract to change the aerodynamic characteristics of the blade thereby changing the aerodynamic characteristics of the scoop portion in responses to changes in the wind. In a preferred embodiment of the invention the aerodynamic adjustment element is in the form of a thin film material that operates to expand or contract to change the aerodynamic characteristics of a blade and consequently the scoop portion in response to changes in the wind. In another preferred embodiment of the invention the aerodynamic adjustment element is in the form of a metallic composite coating that operates to expand or contract to change the aerodynamic characteristics of a blade and consequently the scoop portion in response to changes in the wind. In another preferred embodiment the aerodynamic adjustment element is in the form of a shaped memory material that operates to expand or contract to change the aerodynamic characteristics of a blade and consequently the scoop portion in response to changes in the wind. In a preferred embodiment of the invention the shaped memory material is Nitinol.
Although the foregoing invention has been described in some detail for purposes of clarity of understandings, it will be apparent that certain changes and modifications may be practiced within the scope of any claims. It should now be apparent that the various embodiments presented can be easily modified while keeping within the scope and spirit of the subject invention. Accordingly, it should be understood that the present disclosure is to be considered as exemplary of the principals of the invention and is not intended to limit the invention to the embodiments and the specific examples illustrated and the invention is not to be limited to the details given herein, but may be modified within the scope and equivalents of the descriptions and examples contained herein.
This application claims benefit to and incorporates herein in its entirety U.S. Provisional Patent Application No. 62/708,792, filed in the U.S. Patent and Trademark Office on Dec. 22, 2017 and is a Continuation-In-Part of U.S. patent application Ser. No. 16/225,428 filed Dec. 19, 2018 which is incorporated herein.
Number | Name | Date | Kind |
---|---|---|---|
222256 | Dewees | Dec 1879 | A |
632740 | Parker | Sep 1899 | A |
692714 | Sala et al. | Feb 1902 | A |
2230526 | Claytor | Feb 1941 | A |
2252788 | Sparr | Aug 1941 | A |
3042371 | Fanti | Jul 1962 | A |
3426214 | O'Malley | Feb 1969 | A |
3621930 | Dutchak | Nov 1971 | A |
3877836 | Tompkins | Apr 1975 | A |
3995170 | Graybill | Nov 1976 | A |
4015911 | Darvishian | Apr 1977 | A |
4030298 | Sandoval | Jun 1977 | A |
4039849 | Mater et al. | Aug 1977 | A |
4084918 | Pavlecka | Apr 1978 | A |
4109465 | Plen | Aug 1978 | A |
4111601 | Deberg | Sep 1978 | A |
4191507 | DeBerg | Mar 1980 | A |
4242628 | Mohan et al. | Dec 1980 | A |
4289444 | Monk et al. | Sep 1981 | A |
4329593 | Willmouth | May 1982 | A |
4408958 | Schacle | Oct 1983 | A |
4543042 | Lange | Sep 1985 | A |
4630997 | Cousteau et al. | Dec 1986 | A |
4697761 | Long | Oct 1987 | A |
4722665 | Tyson | Feb 1988 | A |
D300932 | Sikes | May 1989 | S |
5075564 | Hickey | Dec 1991 | A |
5140170 | Henderson | Aug 1992 | A |
5246342 | Bergstein | Sep 1993 | A |
5326225 | Gallivan | Jul 1994 | A |
5333996 | Bergstein | Aug 1994 | A |
5336933 | Emster | Aug 1994 | A |
5463257 | Yea | Oct 1995 | A |
5570859 | Quandt | Nov 1996 | A |
5572816 | Anderson, Jr. et al. | Nov 1996 | A |
5800123 | Trevor | Sep 1998 | A |
6138956 | Monner | Oct 2000 | A |
6164599 | Piening et al. | Dec 2000 | A |
6242818 | Smedley | Jun 2001 | B1 |
6302778 | Andrews | Oct 2001 | B1 |
6382904 | Orlov et al. | May 2002 | B1 |
6419187 | Buter et al. | Jul 2002 | B1 |
6465902 | Beauchamp et al. | Oct 2002 | B1 |
6638005 | Holter et al. | Jul 2003 | B2 |
6717284 | Lin | Apr 2004 | B2 |
6724097 | Wobben | Apr 2004 | B1 |
6765309 | Tallal, Jr. et al. | Jul 2004 | B2 |
6781284 | Peirine et al. | Aug 2004 | B1 |
6808366 | Sikes | Oct 2004 | B2 |
6809432 | Bilgen | Oct 2004 | B1 |
6850821 | Weitkamp | Feb 2005 | B2 |
6870280 | Pechler | Mar 2005 | B2 |
6908287 | Cho | Jun 2005 | B2 |
6925385 | Ghosh et al. | Aug 2005 | B2 |
6952058 | McColn | Oct 2005 | B2 |
6966758 | Grabau et al. | Nov 2005 | B2 |
6984899 | Rice | Jan 2006 | B1 |
7008171 | Whitworth | Mar 2006 | B1 |
7045702 | Kashyap | May 2006 | B2 |
7121807 | Cho | Oct 2006 | B2 |
7215037 | Scalzi | May 2007 | B2 |
7230348 | Poole | May 2007 | B2 |
7242108 | Dable | Jul 2007 | B1 |
7287954 | Kinkaid | Oct 2007 | B2 |
7323791 | Jonsson | Jan 2008 | B2 |
7453168 | Lanie | Nov 2008 | B2 |
7585155 | Park | Sep 2009 | B2 |
7758299 | Jarecki | Jul 2010 | B1 |
7775760 | Finnell | Aug 2010 | B1 |
7880323 | Menges | Feb 2011 | B2 |
7896608 | Whitworth | Mar 2011 | B2 |
D638358 | Sauer | May 2011 | S |
8193657 | Paluszek | Jun 2012 | B2 |
8241000 | Blanton | Aug 2012 | B2 |
8258645 | Barber | Sep 2012 | B2 |
8282339 | Sankar | Oct 2012 | B2 |
8288884 | Malcolm | Oct 2012 | B1 |
8303250 | Mohammed | Nov 2012 | B2 |
8338973 | Suzuki | Dec 2012 | B2 |
8421260 | Duke | Apr 2013 | B2 |
8450872 | Richard | May 2013 | B2 |
8506248 | Wilson | Aug 2013 | B2 |
8529211 | Blanton | Sep 2013 | B2 |
8648481 | Menges | Feb 2014 | B2 |
8747067 | Barban | Jun 2014 | B2 |
8864440 | Sauer | Oct 2014 | B2 |
8905704 | Sauer | Dec 2014 | B2 |
9278744 | Bailey | Mar 2016 | B1 |
9309863 | Foss | Apr 2016 | B2 |
9366228 | Menges | Jun 2016 | B2 |
9464621 | Barban | Oct 2016 | B2 |
9482204 | Plourde | Nov 2016 | B2 |
9494137 | Hwang | Nov 2016 | B2 |
9562511 | Kaste | Feb 2017 | B2 |
9841032 | Henner | Dec 2017 | B2 |
9890761 | Kasten | Feb 2018 | B2 |
9970453 | Henner | May 2018 | B2 |
10094361 | Bardia | Oct 2018 | B2 |
10288036 | Liu | May 2019 | B2 |
10408192 | Gonzalez | Sep 2019 | B2 |
10697467 | Froh | Jun 2020 | B2 |
20010048089 | Clark et al. | Dec 2001 | A1 |
20030133782 | Holter et al. | Jul 2003 | A1 |
20030175109 | Brock et al. | Sep 2003 | A1 |
20030218337 | Lin | Nov 2003 | A1 |
20040100103 | Becherocci et al. | May 2004 | A1 |
20040160059 | Pandian | Aug 2004 | A1 |
20040230377 | Ghosh et al. | Nov 2004 | A1 |
20060056972 | DeLong | Mar 2006 | A1 |
20070077145 | Kinkaid | Apr 2007 | A1 |
20070284885 | Menges | Dec 2007 | A1 |
20080079263 | Morharia et al. | Apr 2008 | A1 |
20100266407 | Barber | Oct 2010 | A1 |
20100316500 | Blanton | Dec 2010 | A1 |
20110095531 | Menges | Apr 2011 | A1 |
20110148117 | Huang | Jun 2011 | A1 |
20120121416 | Sauer | May 2012 | A1 |
20120301301 | Sauer | Nov 2012 | A1 |
20120301310 | Blanton | Nov 2012 | A1 |
20140159368 | Menges | Jun 2014 | A1 |
20150104312 | Barban | Apr 2015 | A1 |
20150204300 | Kasten | Jul 2015 | A1 |
20150316025 | Enevoldsen | Nov 2015 | A1 |
20160084223 | Gonzalez | Mar 2016 | A1 |
20160312769 | Menges | Oct 2016 | A1 |
20170089322 | Liu | Mar 2017 | A1 |
20180156198 | Menges | Jun 2018 | A1 |
20180372069 | Church | Dec 2018 | A1 |
20190360465 | Moore | Nov 2019 | A1 |
Number | Date | Country |
---|---|---|
40 39 203 | Feb 1992 | DE |
43 22 058 | Feb 1994 | DE |
195 30 253 | Nov 1996 | DE |
196 23 055 | Jan 1997 | DE |
100 10 258 | Jun 2001 | DE |
2267652 | Nov 1975 | FR |
2899651 | Apr 2006 | FR |
2 072 756 | Oct 1981 | GB |
411125171 | May 1999 | JP |
02000161196 | Jun 2000 | JP |
WO 2006123951 | Nov 2006 | WO |
WO 2007126704 | Nov 2007 | WO |
Entry |
---|
USPTO Office Action dated Dec. 10, 2019 for U.S. Appl. No. 16/225,428. |
Number | Date | Country | |
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62708792 | Dec 2017 | US |
Number | Date | Country | |
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Parent | 16225428 | Dec 2018 | US |
Child | 16896746 | US |