Noise reduction device for a rotor blade in a wind turbine

Abstract

Rotor blade arrangement (100) for a wind turbine (10), comprising: a rotor blade (16) with surfaces defining a pressure side (22), a suction side (24), a leading edge (26) and a trailing edge (28) extending between a blade tip (32) and a blade root (34); and a noise reducer (110) mounted on a pressure side (22) or on a suction side (24) of the rotor blade (16) and formed adjacent to the trailing edge (28) of the rotor blade (16), wherein the noise reducer (110) has several teeth (120) and several auxiliary noise reduction devices (130) each with several bristles (140), wherein each of the multiple prongs (120) has a pressure-side surface (122), a suction-side surface (124), and an intermediate surrounding area (128) with a circumferential edge surface (126), and wherein each of the several bristles (140) extends from the circumferential surface (126) from one of the several teeth (120).

Description

[0001] This disclosure relates generally to wind turbine blades, and more particularly to noise reducers formed on the blades.

[0002] Wind power is considered one of the cleanest, most environmentally friendly energy sources currently available, and wind turbines have received increased attention in this regard. A modern wind turbine typically includes a tower, a generator, a gearbox, a nacelle, and one or more rotor blades. The rotor blades capture kinetic energy from the wind using familiar wing principles and transfer the kinetic energy via rotational energy to rotate a shaft that connects the rotor blades to a gearbox, or, if no gearbox is used, directly to the generator. The generator then converts the mechanical energy into electrical energy, which can be delivered to a power grid.

[0003] For example, DE 10 2008 007 908 A1 relates to a rotor blade trailing edge arrangement. US 5 088 665 A relates to a structure for reducing air resistance. US 5 533 865 A relates to a wind turbine. EP 2 028 366 A2 relates to a wind turbine with anti-noise devices. DE 10 2007 046 253 A1 relates to a wind turbine rotor blade with acoustic fairing.

[0004] In many cases, various components are attached to the rotor blades of wind turbines to perform different functions during operation of the wind turbines. These components are often attached near the trailing edges of the rotor blades. For example, noise reducers can be attached near the trailing edges of the rotor blades to reduce noise and increase efficiency in conjunction with the rotor blades. However, typical conventional noise reducers have a variety of disadvantages and cannot adequately reduce the noise associated with typical rotor blades. For example, many currently known noise reducers contain multiple prongs. The prongs are designed to reduce noise when the wind flow over the noise reducer is flowing in a particular direction. However, if the wind flow changes, the effectiveness of the prongs in reducing noise may be reduced.

[0005] Thus, an improved noise reducer for a rotor blade would be desirable. For example, a noise reducer with improved noise reduction properties would be advantageous. In particular, a noise reducer with noise reduction devices that have improved responsiveness to the wind flow over the noise reducer would be desirable.

[0006] Aspects and advantages of the invention will be set forth in part in the description which follows, or may be obvious from the description, or may be learned by practice of the invention.

[0007] According to one aspect, a rotor blade assembly for a wind turbine is provided according to claim 1. A rotor blade assembly includes a rotor blade having surfaces defining a pressure side, a suction side, a leading edge, and a trailing edge extending between a tip and a root. The rotor blade assembly further includes a noise reducer formed on a surface of the rotor blade. The noise reducer includes a plurality of noise reduction devices and a plurality of auxiliary noise reduction devices. Each of the plurality of auxiliary noise reduction devices is formed on one of the plurality of noise reduction devices.

[0008] According to a further aspect, a wind turbine according to the independent claim is specified.

[0009] These and other features, aspects, and advantages of the present invention will become more fully understood by reference to the following description and the 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.

[0010] A complete and fundamental disclosure of the present invention, including the best mode thereof, directed to those skilled in the art is described below in the specification with reference to the accompanying drawings, in which: Fig. 1 is a perspective view of one embodiment of a wind turbine of the present disclosure; Fig. 2 is a perspective view of one embodiment of a rotor blade assembly of the present disclosure; Fig. 3 is a perspective view of one embodiment of a noise reducer of the present disclosure; Fig. 4 is a perspective view of another embodiment of a noise reducer of the present disclosure; Fig. 5 is a perspective view of another embodiment of a noise reducer of the present disclosure; Fig. 6 a cross-sectional view along lines 6-6 of Fig. 5 is of one embodiment of a noise reducer of the present disclosure; Fig. 7 is a perspective view of another embodiment of a noise reducer of the present disclosure; and Fig. 8 is a cross-sectional view taken along lines 8-8 of Fig. 7 is of one embodiment of a noise reducer of the present disclosure.

[0011] Reference will now 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 illustration of the invention and not by way of limitation thereof. Indeed, it will be apparent to those skilled in the art that various modifications and variations may be made in the present invention without departing from the scope or spirit of the invention. For example, features shown and described as part of one embodiment may be utilized in another embodiment to obtain yet another embodiment. Thus, the present invention is intended to cover such modifications and variations provided they come within the scope of the appended claims and their equivalents.

[0012] Fig. Figure 1 illustrates a wind turbine 10 of conventional design. The wind turbine 10 includes a tower 12 with a nacelle 14 mounted thereon. Several rotor blades 16 are attached to a rotor hub 18, which in turn is attached to a main flange that rotates a main rotor shaft. The power generation and control components of the wind turbine are housed in the nacelle 14. The view of Fig. Figure 1 is provided for illustrative purposes only to place the present invention in an exemplary application environment. It should be understood that the invention is not limited to any specific type of wind turbine.

[0013] With reference to Fig. 2, a rotor blade 16 according to the present disclosure has a pressure side 22 and a suction side 24 (see Fig. 3 to Fig. 5) defining surfaces extending between a leading edge 26 and a trailing edge 28, and extending from a blade tip 32 to a blade root 34.

[0014] In some embodiments, the rotor blade 16 may include a plurality of individual blade segments aligned in an end-to-end order from the blade tip 32 to the blade root 34. Each of the individual blade segments may be uniquely designed such that the plurality of blade segments define a complete rotor blade 16 with a designed aerodynamic profile, length, and other desired characteristics. For example, each of the blade segments may have an aerodynamic profile that corresponds to the aerodynamic profile of adjacent blade segments. Thus, the aerodynamic profiles of the blade segments may define a contiguous profile of the rotor blade 16. Alternatively, the rotor blade 16 may be formed as a single, one-piece blade with the designed aerodynamic profile, length, and other desired characteristics.

[0015] The rotor blade 16 may be curved in exemplary embodiments. The curvature of the rotor blade 16 may include a bend of the rotor blade 16 substantially in the flap direction and / or substantially in the edge direction. The flap direction may be considered essentially the direction (or the opposite direction) in which aerodynamic lift acts on the rotor blade 16. The edge direction is substantially perpendicular to the flap direction. The flap curvature of the rotor blade 16 is also known as pre-bend, while the edge curvature is known as sweep. Thus, the curved rotor blade 16 may be pre-bent and / or pre-curved. The curvature may enable the rotor blade 16 to better withstand loads in the direction of impact and edge direction during operation of the wind turbine 10 and may further provide a distance of the rotor blade 16 from the tower 12 during operation of the wind turbine 10.

[0016] According to the presentation in the Fig. 2 to Fig. 8, the present disclosure is further directed to a rotor blade assembly 100. The rotor blade assembly 100 includes a noise reducer 110 and a rotor blade 16. Generally, the noise reducer 110 may be formed on a surface of the rotor blade 10 and may reduce the aerodynamic noise emitted by the rotor blade during operation of the wind turbine 10 and / or increase the efficiency of the rotor blade 16. The noise reducer 110 is formed on a surface of the rotor blade 16 adjacent the trailing edge 18 of the rotor blade 16.

[0017] In exemplary embodiments as shown in the Fig. 2 to Fig. 8, the noise reducer 110 may be configured to be mounted on the pressure side 22 of the rotor blade 16. In alternative embodiments, the noise reducer 110 may be configured to be mounted on the suction side 24. In yet further alternative embodiments, the noise reducer 110 may be configured on the rotor blade 16 between the pressure side 22 and the suction side 24.

[0018] For example, the noise reducer 110 may be formed on the trailing edge 28 between the pressure side 22 and the suction side 24. In this embodiment, the rotor blade 16 may be constructed from one or more shell sections. For example, one shell section may include the pressure side 22 and extend between the leading edge 26 and the trailing edge 28, while another shell section may include the suction side 24 and extend between the leading edge and the trailing edge 28. The noise reducer 110 may be mounted between these shell sections such that one portion of the noise reducer 110 is disposed inside the rotor blade 16, while another portion extends away from the rotor blade 16. Alternatively, the noise reducer 110 may extend through a shell section of the rotor blade 16 at a desired location, such as at the trailing edge 28.In further alternative embodiments, the noise reducer 110 may be mounted directly on the outside of the rotor blade 16 between the pressure side 22 and the suction side 24, for example, using a suitable adhesive or other mechanical fasteners. For example, in exemplary embodiments, the noise reducer 110 may be mounted directly on the trailing edge 28.

[0019] According to the presentation in the Fig. 2 to Fig. 8, the noise reducer 110 of the present disclosure includes a plurality of noise reduction devices 112. Essentially, the noise reduction devices 112 can interact with the wind flow at the noise reducer 110 when the rotor blade assembly 100 is in operation and can reduce the noise associated with the rotor blade 16.

[0020] In some versions, as shown in Fig. 2, the noise reducer 110 includes a base plate 114. In these embodiments, the base plate 114 may be substantially a portion of the noise reducer 110 that is attached to the rotor blade 16 to form the noise reducer 110 on a surface of the rotor blade 16, and the noise reduction device 112 may extend from the base plate 114. Alternatively, the noise reduction devices 112 may be attached directly to the rotor blade 16 or may be an integral part of the rotor blade 16. For example, in some embodiments in which the noise reducer 110 is mounted adjacent the trailing edge 28, the noise reduction devices 112 may extend directly from the trailing edge 28.

[0021] In some embodiments, the noise reducer 110 may be constructed from multiple noise reducer sections. Each section may include one or more noise reduction devices 112, and each section may further include a base plate portion. Alternatively, the noise reducer 110 may be a single, one-piece component.

[0022] In exemplary embodiments as shown in the Fig. 2 to Fig. 8, each portion of the noise reduction devices 112 includes a prong 120. Although in exemplary embodiments the prongs 120 are substantially V-shaped, in alternative embodiments the prongs 120 may be U-shaped, or may have any other shape or configuration suitable for reducing the noise emitted by the rotor blade 16 during operation of the wind turbine 10.

[0023] Each of the prongs 120 includes a pressure-side surface 122 and a suction-side surface 124. Additionally, each of the prongs 120 includes a peripheral edge surface 126 disposed between and connecting opposing surfaces (pressure-side surface 122, suction-side surface 124). Further, each noise reduction device 112 defines a surrounding area 128. The noise reduction devices 112 include prongs 120, where the surrounding area 128 may be defined by a peripheral edge surface 126 and / or the pressure-side surface 122 and the suction-side surface 124, as shown.

[0024] However, it should be understood that the present disclosure is not limited to prongs 120. The noise reduction devices 112 comprise bristles. The noise reduction devices may comprise any suitable apparatus configured to interact with the wind flow and reduce noise associated with the rotor blade 16.

[0025] According to the presentation in the Fig. 2 to Fig. 8, the noise reducer 110 of the present disclosure includes a plurality of auxiliary noise reduction devices 130. Essentially, the auxiliary noise reduction devices 130 may further interact with the wind flow past the noise reducer 110 when the rotor blade assembly 100 is in operation and may further reduce noise associated with the rotor blade 16. For example, during operation of the wind turbine 10, the direction of the wind flow past the noise reducer 110 may change or vary. The noise reduction devices 112, in some embodiments, may be configured for optimal noise reduction when the wind passes in a particular direction past the noise reducer 110. Thus, if the direction of the wind flow changes or varies, the noise reduction devices 112 may not produce optimal noise reduction.The auxiliary noise reduction devices 130 may thus provide additional noise reduction capabilities to the noise reducer 110, complementing the noise reduction capabilities of the noise reduction devices 112. The auxiliary noise reduction devices 130 may thus be particularly useful when the wind direction at the noise reducer 110 changes or varies, as discussed above.

[0026] Each of the plurality of auxiliary noise reduction devices 130 may be formed on at least one of the noise reduction devices 112. For example, as discussed below, in some embodiments, an auxiliary noise reduction device 130 may be formed on the pressure-side surface 122 or the suction-side surface 124 of a noise reduction device 112. An auxiliary noise reduction device 130 is formed on a peripheral edge surface 126 of the noise reduction device 112. An auxiliary noise reduction device 130 may be formed on the surrounding region 128 of the noise reduction device 112. Further, in some embodiments, an auxiliary noise reduction device 130 may be formed at an intersection between adjacent noise reduction devices 112.For example, an auxiliary noise reduction device 130 may be formed at an intersection and on a peripheral edge surface 126 or at a surrounding area 128 of adjacent noise reduction devices 112.

[0027] Fig. 2, Fig. 3, Fig. 5 and Fig. 6 illustrate the noise reducer 110 with one embodiment of the auxiliary noise reduction device 130 of the present disclosure. The auxiliary noise reduction devices 130 each include a plurality of bristles 140. Thus, at least a portion of the auxiliary noise reduction devices 130 may include a plurality of bristles 140. Each of the plurality of bristles 140 may extend from a surface of the noise reduction devices 112 on which the bristles 140 are formed. The noise reduction devices 112 are prongs 120, with the bristles 140 extending from the peripheral edge surface 126, as shown. Bristles 140 may extend from the pressure-side surface 122 or the suction-side surface 124.

[0028] In some embodiments, as shown, the bristles 140, or at least a portion thereof, may extend substantially perpendicularly with respect to a surface of the rotor blade 16. For example, the bristles 140, or at least a portion thereof, may extend substantially perpendicularly with respect to the surface of the rotor blade 16 on which the noise reducer 110 is formed, or with respect to a surface adjacent to the noise reducer 110. In exemplary embodiments, as shown, at least a portion of the bristles 140 may extend substantially perpendicularly with respect to the trailing edge 28 of the rotor blade 16.

[0029] In further embodiments, the bristles 140, or at least a portion thereof, may extend substantially perpendicularly with respect to the noise reduction devices 112, such as with respect to the surface of the noise reduction device 112 on which the bristles 140 are formed. In some embodiments, at least a portion of the bristles 140 may extend substantially perpendicularly with respect to the peripheral edge of the surrounding area 128.

[0030] Furthermore, in further embodiments, the bristles 140, or at least a portion thereof, may extend in a range between approximately 5° and approximately 90° from a normal to a surface of the rotor blade 16. In further embodiments, the bristles 140, or at least a portion thereof, may extend in a range between approximately 5° and approximately 90° from a normal with respect to the noise reduction devices 112, such as with respect to the noise reduction device 112 on which the bristles 140 are formed.

[0031] It should be understood, however, that the bristles 140 according to the present disclosure are not limited to the orientations discussed above, and that instead, bristles 140 extending from the noise reduction devices 112 at any suitable angle are within the scope and spirit of the present disclosure.

[0032] The bristles 140 according to the present disclosure may be made of essentially any material suitable for providing the desired noise reduction properties. For example, in some embodiments, the bristles 140 may be made of thermoplastics or thermoplastic / glass composite fibers. Alternatively, the bristles 140 may be made of, for example, nylon, a polyester, a Kevlar, or any suitable composite material. However, it should be understood that the present disclosure is not limited to the materials disclosed above, and instead, any suitable materials are within the scope and spirit of the present disclosure.

[0033] Fig. 4 illustrates a noise reducer 110 incorporating another embodiment of the auxiliary noise reduction device 130 of the present disclosure. In these embodiments, the auxiliary noise reduction devices 130 each include a plurality of tufts 150. Thus, at least a portion of the auxiliary noise reduction devices 130 may include a plurality of tufts 150. Essentially, a tuft 150 is a group of strands 152 comprising bristles made of any suitable materials that substantially converge at one end and substantially diverge as they extend from that end. For example, as shown in Fig. 4, each tuft 150 includes a plurality of strands 152 extending between first converging ends 154 and second diverging ends 156. Each of the plurality of tufts 150 may extend from a surface of the noise reduction device 112 on which the tufts 150 are formed. The noise reduction devices 112 are prongs 120, with the tufts 150 extending from the peripheral edge surface 126, as shown. Tufts 150 may extend from the pressure-side surface 122 or the suction-side surface 124.

[0034] Fig. 7 and Fig. 8 illustrate a noise reducer 110 with another embodiment of the auxiliary noise reduction device 130 of the present disclosure. In these embodiments, the auxiliary noise reduction devices 130 each include a porous layer 160. Thus, at least a portion of the auxiliary noise reduction devices 130 may include a porous layer 160. Each of the porous layers 160 may be disposed adjacent to a noise reduction device 112. For example, in embodiments in which the noise reduction devices 112 are prongs 120, a porous layer 160 may be disposed adjacent, for example, the pressure-side surface 122, the suction-side surface 124, or, as shown, the peripheral edge surface 126.

[0035] In some embodiments, the porous layer 160 may comprise a felt material. Alternatively, the porous layer 160 may be any porous material suitable for reducing noise associated with the rotor blade 16.

[0036] In exemplary embodiments, the auxiliary noise reduction devices 130, or a portion thereof, may extend beyond the surrounding area 128 of the noise reduction devices 112 on which the auxiliary noise reduction devices 130 are formed. The noise reduction devices 112 are prongs 120, and the auxiliary noise reduction devices 130 may extend beyond the peripheral edge surface 126 and / or the surrounding area 128 of the prongs 120. Fig. 2 to Fig. 6 illustrate the bristles 140 and tufts 150 extending from the peripheral edge surface 126 of various prongs 120 and thus beyond the peripheral edge surface 126 and the surrounding area 128 of the prongs 120. Likewise, Fig. 7 and Fig. 8 shows the porous layers 160 arranged adjacent to the suction side surface 124 and extending beyond the peripheral edge surface 126 and the surrounding area 128 of the prongs 120.

[0037] The noise reduction devices 112 and auxiliary noise reduction devices 130 may be formed and attached using any suitable processes and / or devices. For example, in some embodiments, the noise reduction devices 112 may be injection-molded with various auxiliary noise reduction devices 130 such that the bristles 140 and / or the tufts 150 are included therein. Alternatively, various auxiliary noise reduction devices 130 may be formed and placed in a mold, and the noise reduction devices 112 may be injection-molded around the auxiliary noise reduction devices 130. Alternatively, the auxiliary noise reduction devices, such as the bristles 140, the tufts 150, and / or the porous layers 180, may be attached to the noise reduction devices 112 using any suitable adhesive, bonding technique, or mechanical fastener.

[0038] Alternatively, the auxiliary noise reduction devices 130 may be attached to the noise reduction devices 112 via various channels 170 and attachment devices 172. As shown in the Fig. 5 and Fig. 6, for example, the noise reduction devices 112 or a portion thereof may each define a channel 170 or channels 170 therein. Furthermore, fastening devices 172 may be provided, and the fastening devices 172 may be configured for connection to the channels 170. For example, the fastening devices 172 may be substantially shaped and sized to fit within the channels 170. The auxiliary noise reduction devices 130 may be formed on the fastening devices 172. Thus, to form the auxiliary noise reduction devices 130 on the noise reduction devices 112, the fastening devices 172 may be connected to the channels 170. The auxiliary noise reduction devices 130 may protrude from the channels 170.

[0039] As it is in the Fig. 5 and Fig.6, the noise reduction devices 112 are prongs 120, and channels 170 may be defined in the peripheral edge surfaces 126 of the channels 170. Alternatively, however, the channels 170 may be defined in the pressure-side surface 122 or the suction-side surface 124, or may be defined anywhere in the surrounding area 128 of a noise reduction device 112.

[0040] The channels 170 and the attachment devices 172 can enable separate fabrication and joint formation of the noise reduction device 112 and the auxiliary noise reduction device 130 as desired or needed. For example, in some embodiments, the noise reducer 110 can be used without the auxiliary noise reduction devices 130 during certain wind conditions and with the auxiliary noise reduction devices 130 during other wind conditions. The channels 170 and the attachment devices 172 enable simple and efficient formation of the auxiliary noise reduction devices 130 on the noise reduction devices 112.

[0041] This description uses examples to disclose the invention, including the best mode, and to enable any person skilled in the art to practice the invention, including making and using all elements and systems and performing all incorporated methods. The patentable scope of the invention is defined by the claims and may include other examples that would be apparent to one skilled in the art. Such other examples are intended to be included within the scope of the invention if they contain structural elements that do not differ from the language of the claims, or if they contain equivalent structural elements with insubstantial changes from the language of the claims.

[0042] A rotor blade assembly for a wind turbine is disclosed. The rotor blade assembly includes a rotor blade having surfaces defining a pressure side, a suction side, a leading edge, and a trailing edge extending between a tip and a root. The rotor blade assembly further includes a noise reducer formed on a surface of the rotor blade. The noise reducer includes a plurality of noise reduction devices and a plurality of auxiliary noise reduction devices. Each of the plurality of auxiliary noise reduction devices is formed on one of the plurality of noise reduction devices.

Claims

[1] Rotor blade assembly (100) for a wind turbine (10), comprising: a rotor blade (16) having surfaces defining a pressure side (22), a suction side (24), a leading edge (26), and a trailing edge (28) extending between a blade tip (32) and a blade root (34); and a noise reducer (110) mounted on a pressure side (22) or on a suction side (24) of the rotor blade (16) and formed adjacent to the trailing edge (28) of the rotor blade (16), the noise reducer (110) having a plurality of prongs (120) and a plurality of auxiliary noise reduction devices (130) each having a plurality of bristles (140), wherein each of the plurality of prongs (120) has a pressure side surface (122), a suction side surface (124), and an intermediate surrounding area (128) having a peripheral edge surface (126), and wherein each of the plurality of bristles (140) extends from the peripheral edge surface (126) of one of the plurality of prongs (120). [2] The rotor blade assembly (100) of claim 1, wherein at least a portion of the plurality of bristles (140) extends substantially perpendicularly with respect to the trailing edge (28) of the rotor blade (16). [3] The rotor blade assembly (100) of claim 1, wherein at least a portion of the plurality of bristles (140) extends substantially perpendicularly with respect to the peripheral edge surface (126) of one of the plurality of prongs (120). [4] The rotor blade assembly (100) of any preceding claim, wherein at least a portion of the plurality of auxiliary noise reduction devices (130) each comprise a plurality of tufts (150), each of the plurality of tufts (150) extending from the peripheral edge surface (126) of one of the plurality of tines (120). [5] The rotor blade assembly (100) of any preceding claim, wherein at least a portion of the plurality of auxiliary noise reduction devices (130) each comprises a porous layer (160), each of the porous layers (160) being disposed adjacent to one of the pressure side surface (122) or the suction side surface (124) of one of the plurality of tines (120). [6] The rotor blade assembly (100) of claim 5, wherein at least a portion of the plurality of porous layers (160) extends beyond the peripheral edge surface (126) of the tine (120) on which the porous layer (160) is disposed. [7] The rotor blade assembly (100) of any preceding claim, wherein at least a portion of the plurality of prongs (120) each defines a channel (170), further comprising a plurality of attachment devices (172) configured to connect to the channels (170), and wherein at least a portion of the plurality of auxiliary noise reduction devices (130) is formed on the attachment devices (172). [8] The rotor blade assembly (100) of claim 7, wherein at least a portion of the channels (170) are defined in the peripheral edge surfaces (126) of the serrations (140). [9] Rotor blade assembly (100) according to one of the preceding claims, wherein the noise reducer (110) has a base plate (114) adapted to attach the noise reducer (110) to a surface of the rotor blade (16). [10] Rotor blade assembly (100) according to claim 9, wherein the base plate (114) is formed as a portion of the noise reducer (110). [11] The rotor blade assembly (100) of claim 10, wherein the noise reducer (110) extends from the base plate (114). [12] Wind turbine (10), comprising: a plurality of rotor blades (16), each of the rotor blades (16) having surfaces defining a pressure side (22), a suction side (24), a leading edge (26), and a trailing edge (28) extending between a blade tip (32) and a blade root (34); and a noise reducer (110) formed on a pressure side (22) or on a suction side (24) of at least one of the plurality of rotor blades (16) adjacent to the trailing edge (28) of the rotor blade (16), wherein the noise reducer (110) has a plurality of prongs (120) and a plurality of auxiliary noise reduction devices (130) each having a plurality of bristles (140), wherein each of the plurality of prongs (120) has a pressure side surface (122), a suction side surface (124), and an intermediate surrounding area (128) having a peripheral edge surface (126), and wherein each of the plurality of bristles (140) extends from the peripheral edge surface (126) of one of the plurality of prongs (120). [13] The wind turbine (10) of claim 12, wherein at least a portion of the plurality of bristles (140) extends substantially perpendicularly with respect to the trailing edge (28) of the rotor blade (16). [14] The wind turbine (10) of claim 12, wherein at least a portion of the plurality of bristles (140) extends substantially perpendicularly with respect to the peripheral edge surface (126) of one of the plurality of prongs (120). [15] The wind turbine (10) of any one of claims 12 to 14, wherein at least a portion of the plurality of auxiliary noise reduction devices (130) each comprise a plurality of tufts (150), each of the plurality of tufts (150) extending from the peripheral edge surface (126) of one of the plurality of prongs (120). [16] A wind turbine (10) according to any one of claims 12 to 15, wherein at least a portion of the plurality of auxiliary noise reduction devices (130) each comprises a porous layer (160), each of the porous layers (160) being disposed adjacent to one of the pressure side surface (122) or the suction side surface (124) of one of the plurality of prongs (120). [17] The wind turbine (10) of claim 16, wherein at least a portion of the plurality of porous layers (160) extends beyond the peripheral edge surface (126) of the tine (120) on which the porous layer (160) is disposed. [18] Wind turbine (10) according to one of claims 12 to 17, wherein at least a portion of the plurality of prongs (120) each defines a channel (170), further comprising a plurality of attachment devices (172) configured to connect to the channels (170), and wherein at least a portion of the plurality of auxiliary noise reduction devices (130) is formed on the attachment devices (172). [19] Wind turbine (10) according to one of claims 12 to 18, wherein at least a portion of the channels (170) are defined in the peripheral edge surfaces (126) of the prongs (140). [20] Wind turbine (10) according to one of claims 12 to 19, wherein the noise reducer (110) has a base plate (114) which is designed to fasten the noise reducer (110) to a surface of the rotor blade (16), and in particular wherein the base plate (114) is designed as a section of the noise reducer (110).

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