WIND TURBINE ROTOR BLADES WITH ULTRAVIOLET LIGHT-REFLECTIVE SUBSTANCES
A wind turbine rotor blade is disclosed that includes a body extending between a blade root and a blade tip. The body may include a pressure side and a suction side extending between a leading edge and a trailing edge and may define an outer surface. In addition, an ultraviolet light-reflective tape may be disposed on the outer surface of the body.
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The present subject matter relates generally to wind turbines and, more particularly, to wind turbine rotor blades having ultraviolet light-reflective substances disposed thereon and/or dispersed therein in order to prevent bird strikes.
BACKGROUND OF THE INVENTIONWind power is considered one of the cleanest, most environmentally friendly energy sources presently available, and wind turbines have gained increased attention in this regard. However, while being considered environmentally safe, wind turbines pose a significant threat to birds. Specifically, it has been found that birds in flight have trouble perceiving the rotating rotor blades of a wind turbine. As a result, birds tend to fly directly into and strike the rotor blades, causing damage to the rotor blades as well significant injury and/or death to the birds. The occurrence of such bird strikes have led many to enact regulations and/or laws prohibiting and/or discouraging the placement of wind turbines in migratory pathways, in areas of high bird populations and/or in areas that may attract high bird populations in the future.
Many believe that bird strikes result from motion smear caused by the high velocity rotation of wind turbine rotor blades. In general, motion smear is a term used to describe the degradation in perception that results from the inability of the retina of the eye to process high temporal frequencies of stimulation occurring from high velocity retinal-image motion. In other words, motion smear refers to the phenomenon that causes an object, which is moving across the retina with increasing speed, to become progressively blurred. For instance, in the case of wind turbines, motion smear occurs primarily at the tips of the rotor blades, making the blade tips appear almost transparent at high retinal-image velocities. Accordingly, birds flying near wind turbines often fail to perceive the rotating blades, thereby resulting in bird strikes.
Accordingly, a rotor blade configuration that reduces the occurrence of bird strikes, such as by preventing or limiting motion smear, would be welcomed in the technology.
BRIEF DESCRIPTION OF THE INVENTIONAspects and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the invention.
In one aspect, the present subject matter discloses a wind turbine rotor blade. The rotor blade may include a body extending between a blade root and a blade tip. The body may include a pressure side and a suction side extending between a leading edge and a trailing edge and may define an outer surface. In addition, an ultraviolet light-reflective tape may be disposed on the outer surface of the body.
In another aspect, the present subject matter discloses a wind turbine rotor blade. The rotor blade may include a body extending between a blade root and a blade tip. The body may include a pressure side and a suction side extending between a leading edge and a trailing edge. Additionally, a transparent coating may define an outer surface of the body. Moreover, an ultraviolet light-reflective substance may be disposed beneath the outer surface.
In a further aspect, the present subject matter discloses a wind turbine rotor blade. The rotor blade may include a body extending between a blade root and a blade tip. The body may include a pressure side and a suction side extending between a leading edge and a trailing edge. Additionally, an ultraviolet light-reflective substance may define a pattern along at least a portion of the body.
These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.
A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures, in which:
Reference now will be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents.
In general, the present subject matter discloses a wind turbine rotor blade having an ultraviolet (UV) light-reflective substance disposed thereon and/or dispersed therein. For example, in several embodiments, the UV light-reflective substance may comprise UV light-reflective tape attached to the outer surface of the rotor blade. In other embodiments, the UV light-reflective substance may comprise UV light-reflective paint, UV light-reflective materials, UV brighteners, UV reflectors and/or the like. Additionally, in several embodiments, the UV light-reflective substance may be configured to define a pattern on the rotor blade. For instance, in one embodiment, the UV light-reflective substance may be configured to form a plurality of stripes extending in a chordwise direction between the leading and trailing edges of the rotor blade.
By disposing and/or dispersing a UV light-reflective substance on and/or within the rotor blade, it is believed that the occurrence of bird strikes may be significantly reduced. Specifically, as is generally understood, most birds are tetrachromatic and, thus, are able to perceive light waves in the UV spectrum as a particular color. As such, the UV light-reflective substance disposed on and/or dispersed within the rotor blade may reflect UV light waves off the surface of the blade, thereby providing contrasting colors that may be perceived by a passing bird. For instance, a color contrast may be created between the perceived color of the reflected UV light and the perceived color of the rotor blade's background (e.g., the perceived color of the sky) and/or between the perceived color of the reflected UV light and the perceived color of the portion of the blade not reflecting UV light. Such color contrast may prevent and/or limit motion smear of the retinal-images perceived by a passing bird, thereby reducing the likelihood of the occurrence of a bird strike. Moreover, as will be described below, the use of UV light-reflective substances with rotor blades may also decrease erosion and/or environmental wear of the rotor blade, limit UV degradation of rotor blade coatings and/or the blade material and/or minimize thermal transients caused by exposure to UV radiation.
Referring now to the drawings,
Referring now to
As indicated above, the blade body 24 may generally define an aerodynamic profile or shape. For example, in several embodiments, the blade body 24 may define an airfoil shaped cross-section, such as by defining a symmetrical or cambered airfoil-shaped cross-section. In addition, the blade body 24 may also be aeroelastically tailored. Aeroelastic tailoring of the blade body 24 may entail bending of the body 24 in a generally chordwise direction and/or in a generally spanwise direction. The chordwise direction generally corresponds to a direction parallel to the chord 36. The spanwise direction generally corresponds to a direction parallel to the span 34. Aeroelastic tailoring may further entail twisting of the blade body 24, such as twisting of the body 24 in a generally chordwise and/or spanwise direction.
Additionally, in several embodiments, the blade body 24 may be formed as a single, unitary component. Alternatively, the blade body 24 may be formed from a plurality of shell components. For example, the blade body 24 may be manufactured from a first shell half (not shown) generally defining the pressure side 26 of the body 24 and a second shell half (not shown) generally defining the suction side 28 of the body 24, with such shell halves being secured to one another at the leading and trailing edges 30, 32. Moreover, it should be appreciated that the blade body 24 may be formed from any suitable blade material. For instance, in one embodiment, the blade body 24 may be formed from a composite material, such as a carbon fiber reinforced composite material or a glass fiber reinforced composite material. Alternatively, one or more portions of the blade body 24 may be configured as a layered construction and may include a core material, formed from a lightweight material such as wood (e.g., balsa), foam (e.g., extruded polystyrene foam) or a combination of such materials, disposed between layers of composite material.
It should also be appreciated that, in several embodiments, one or more coatings and/or layers of paint may be applied over the blade material of the blade body 24. In such embodiments, an outer surface 38 (
Referring now to
For instance, as shown in
It should be appreciated that, in several embodiments, the UV light-reflective substance 40 may be attached and/or applied onto the rotor blade 16 so as to cover the entire outer surface 38 of the blade body 24. For instance, in one embodiment, the entire outer surface 38 may be covered with UV light-reflective tape, UV light-reflective paint and/or the like such that the entire rotor blade 16 may be perceived by passing birds as a particular color. In other embodiments, the UV light-reflective substance 40 may be attached and/or applied onto the rotor blade 16 so as to only cover a portion of the outer surface 38, thereby creating a color contrast between the portions of the outer surface 38 covered by the UV light-reflective substance 40 and the remainder of the outer surface 38. Regardless, such a color contrast may assist passing birds in perceiving the rotor blades 16 as they rotate during operation of the wind turbine 10.
Additionally, in several embodiments, the UV light-reflective substance 40 may be disposed on the blade body 24 so as to define a pattern along the outer surface 38 of the body 24. For instance, as shown in the illustrated embodiment, the UV light-reflective tape may be attached to the blade body 24 so as to form a plurality of stripes 42 extending along the outer surface 38. Specifically, as shown, the stripes 42 may be formed so as to extend in a chordwise direction between the leading and trailing edges 30, 32 of the blade body 24, such as by extending fully across one or both of the pressure and/or suction sides 26, 28 (
It should be appreciated that, in alternative embodiments, the UV light-reflective substance 40 may be disposed along the blade body 24 so as to form any other suitable pattern that provides a perceptible color contrast between the portions of the outer surface 38 covered by the UV light-reflective substance 40 and the remainder of the outer surface 38. For instance, on one embodiment, a plurality of stripes may be formed by the UV light-reflective substance 40 that extend in the spanwise direction, such as by extending fully or partially between the blade root 20 and the blade tip 22. In another embodiment, the UV light-reflective substance 40 may be disposed on the outer surface 38 so as to form a plurality of stripes extending diagonally along the outer surface 38 (i.e., extending relative to the chordwise and spanwise directions at an angle that is less than 90 degrees and greater than 0 degrees). In a further embodiment, a plurality of stripes may be formed that extend in two or more directions so as to define a checkerboard or cross-hatched pattern along the outer surface 38.
It should also be appreciated that, in several embodiments, a different pattern may be formed on each wind turbine rotor blade 16. For instance, in the illustrated embodiment, the UV light-reflective substance 40 may be attached and/or applied to the rotor blades 16 such that each rotor blade 16 includes chordwise extending stripes 42 that are disposed at differing spanwise locations than the chordwise extending stripes 42 of the remaining rotor blades 16 of the wind turbine 10. Alternatively, the UV light-reflective substance 40 may be attached and/or applied to the rotor blades 16 so as to form the same exact pattern on each rotor blade 16.
Referring now to
In addition to the chordwise extending stripes 142 or as an alternative thereto, at least a portion of the UV light-reflective substance 140 may be disposed along the leading and/or trailing edges 30, 32 of the blade body 24. For instance, as shown in
Similar to the embodiment described above with reference to
For example,
It should be appreciated that the transparent coating 146 may generally be formed using any suitable coating material known in the art. For example, in one embodiment, the transparent coating 146 may be formed using various suitable polymer coating materials (e.g., polyurethane coating materials) and/or the like. Alternatively, the transparent coating 146 may be formed using a transparent or clear tape material.
As shown in
Additionally, as shown in
Referring now to
It should be appreciated that the UV light-reflective substance 140 shown in
It should also be appreciated that, in addition to dispersing UV reflectors and/or UV brighteners within the blade material 148 or as an alternative thereto, the UV reflectors and/or UV brighteners may also be incorporated into and dispersed throughout the transparent coating 146. For example, in one embodiment, the UV reflectors and/or UV brighteners may be mixed within the transparent coating 146 prior to its application onto the blade body 24. Alternatively, the transparent coating 146 may be applied over the UV reflectors and/or UV brighteners in a manner similar to the embodiment described above with reference to
In general, it should be appreciated that the use of UV light-reflective substances 40, 140 as described herein may provide numerous advantages in addition to reducing the likelihood of bird strikes. For example, by reflecting UV light waves, the UV light-reflective substance 40, 140 may prevent and/or reduce UV degradation (e.g., cracking) of the blade material 148 and/or any coatings applied to the blade 16. In addition, the UV light-reflective substance 40, 140 may also limit thermal transients within the blade 16 that may be caused by the absorption of UV radiation within the blade body 24.
Moreover, further advantages may be provided when the UV light-reflective substance 40, 140 comprises UV light-reflective tape. Specifically, because UV light-reflective tape may be attached directly onto the outer surface 38, 138 of the blade body 24, the tape may be retrofitted onto existing rotor blades 16. Additionally, UV light-reflective tape may also be pre-formed and/or pre-cut into a tape blank, which may allow for quick and easy installation of the tape. For example, the UV light-reflective tape may be cut into a tape blank forming all or a portion of the pattern shown in
It should also be appreciated that the use of the UV light-reflective substance 140 with the transparent coating 146 may also provide the rotor blade 16 protection against erosion (e.g., rain and hail erosion) and/or environmental wear.
Additionally, it should be appreciated that the color of the UV light-reflective substances that is perceivable to humans may be chosen so as to not be visually distracting. For instance, the human-perceivable color of the UV light-reflective substances may be the same as the color of the remainder of the blade (e.g., white). As such, while birds may be capable of perceiving the color contrast between the UV light-reflective substances and the remainder of the rotor blades, humans will perceive the rotor blade as having a single color.
This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.
Claims
1. A wind turbine rotor blade, comprising:
- a body extending between a blade root and a blade tip and including a pressure side and a suction side extending between a leading edge and a trailing edge, the body defining an outer surface; and
- an ultraviolet light-reflective tape disposed on the outer surface of the body.
2. The wind turbine rotor blade of claim 1, wherein the ultraviolet light-reflective tape only covers a portion of the outer surface of the body.
3. The wind turbine rotor blade of claim 1, wherein the ultraviolet light-reflective tape defines a pattern along the outer surface of the body.
4. The wind turbine rotor blade of claim 3, wherein the ultraviolet light-reflective tape forms a plurality of stripes extending along the outer surface of the body.
5. The wind turbine rotor blade of claim 4, wherein the plurality of stripes extend in a chordwise direction between the leading and trailing edges of the body.
6. The wind turbine rotor blade of claim 1, wherein at least a portion of the ultraviolet light-reflective tape is disposed along at least a portion of the leading edge of the body.
7. A wind turbine rotor blade, comprising:
- a body extending between a blade root and a blade tip and including a pressure side and a suction side extending between a leading edge and a trailing edge;
- a transparent coating defining an outer surface of the body; and
- an ultraviolet light-reflective substance disposed beneath the outer surface.
8. The wind turbine rotor blade of claim 7, wherein the ultraviolet light-reflective substance is disposed between the outer surface and a blade material of the body.
9. The wind turbine rotor blade of claim 8, wherein the ultraviolet light-reflective substance comprises at least one of an ultraviolet light-reflective paint, an ultraviolet light-reflective tape and an ultraviolet light-reflective material.
10. The wind turbine rotor blade of claim 7, wherein the ultraviolet light-reflective substance comprises at least one of an ultraviolet reflector and an ultraviolet brightener.
11. The wind turbine rotor blade of claim 10, wherein the at least one of the ultraviolet reflectors and the ultraviolet brighteners are dispersed within at least one of the transparent coating and a blade material of the body.
12. The wind turbine rotor blade of claim 7, wherein the ultraviolet light-reflective substance defines a pattern beneath the outer surface.
13. The wind turbine rotor blade of claim 12, wherein the ultraviolet light-reflective substance forms a plurality of stripes extending in a chordwise direction between the leading and trailing edges of the body.
14. The wind turbine rotor blade of claim 7, wherein at least a portion of the ultraviolet light-reflective substance is disposed along at least a portion of the leading edge of the body.
15. A wind turbine rotor blade, comprising:
- a body extending between a blade root and a blade tip and including a pressure side and a suction side extending between a leading edge and a trailing edge; and
- an ultraviolet light-reflective substance defining a pattern along at least a portion of the body.
16. The wind turbine rotor blade of claim 15, wherein the ultraviolet light-reflective substance forms a plurality of stripes extending along the at least a portion of the body.
17. The wind turbine rotor blade of claim 16, wherein the plurality of stripes extend in a chordwise direction between the leading and trailing edges of the body.
18. The wind turbine rotor blade of claim 15, wherein the body defines an outer surface, the ultraviolet light-reflective substance being disposed on the outer surface.
19. The wind turbine rotor blade of claim 15, further comprising a transparent coating defining an outer surface of the body, the ultraviolet light-reflective substance being disposed beneath the outer surface.
20. The wind turbine rotor blade of claim 15, wherein the ultraviolet light-reflective substance comprises at least one of an ultraviolet light-reflective paint, an ultraviolet light-reflective tape, an ultraviolet light-reflective material, an ultraviolet reflector and an ultraviolet brightener.
Type: Application
Filed: Oct 25, 2011
Publication Date: Apr 25, 2013
Applicant: GENERAL ELECTRIC COMPANY (Schenectady, NY)
Inventors: Joel Russell Cloninger, II (Anderson, SC), Nicholas R. Farley (Greenville, SC)
Application Number: 13/280,748
International Classification: F01D 25/00 (20060101);