Winglet for a rotor blade of a wind turbine

Abstract

Winglet (120) for a rotor blade (100) which features: a winglet body (122) extending between a first end (124) and a second end (128), wherein the winglet body (122) defines a sweep (144) and has a curvature defined by a curve fit including a first radius of curvature (154) and a second radius of curvature (156), wherein the sweep (144) defined between the first end (124) and the second end (128) is in the range of about 580 mm to about 970 mm, wherein the first radius of curvature (154) is in the range of about 1500 mm to about 2500 mm and the second radius of curvature (156) is in the range of about 1200 mm to about 2000 mm.

Description

[0001] The present subject matter generally concerns rotor blades for wind turbines and in particular winglets for rotor blades of wind turbines.

[0002] Wind energy is considered one of the cleanest, most environmentally friendly energy sources currently available, and wind turbines have gained increasing 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 well-known airfoil principles and transfer this kinetic energy as rotational energy to turn a shaft that couples 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 fed into a power grid.

[0003] To ensure that wind energy remains a viable energy source for the future, efforts are being made to increase energy yield by modifying the size, configuration, and capacity of wind turbines. One such modification involves incorporating a wingtip device, such as a winglet, at the tip of each rotor blade. However, the use of conventional winglets often presents several disadvantages. For example, many conventional winglets are configured as suction-side winglets, which reduces the clearance between the rotor blades and the wind turbine tower. Furthermore, many conventional winglets are designed solely to reduce noise generated by the wind turbine. In general, these winglets do not have a significant impact on the overall performance and efficiency of the wind turbine.

[0004] Accordingly, a pressure-side winglet, which generally improves the overall performance and efficiency of a wind turbine, would be welcomed in engineering. German patent application DE 103 00 284 A1 discloses a winglet for a rotor blade in general terms, without specifying any concrete dimensions or geometric parameters.

[0005] Some aspects and advantages of the invention are given in the following description or may be obvious from the description, or may be experienced by putting the invention into practice.

[0006] The invention is defined by the claims and relates to a winglet for a rotor blade. The winglet generally comprises a winglet body extending between a first end and a second end. The winglet body has a sweep and a curvature defined by a curve shape comprising a first radius of curvature and a second radius of curvature. According to the invention, the sweep between the first and second ends is in the range of approximately 580 mm to approximately 970 mm. Furthermore, the first radius of curvature is in the range of approximately 1500 mm to approximately 2500 mm, while the second radius of curvature is in the range of approximately 1200 mm to approximately 2000 mm.

[0007] In another aspect, the present document discloses a winglet for a rotor blade. The winglet generally comprises a winglet body extending between a first end and a second end. The winglet body contains several radial points between the first and second ends and defines a chord and a twist angle at each of the several radial points, essentially according to the chord and twist angle values ​​illustrated in Table 1. Each of the chord values ​​illustrated in Table 1 can be varied by + / -25%, and each of the twist angle values ​​illustrated in Table 1 can be varied by + / -2.5°.

[0008] In another aspect, the present subject matter discloses a winglet for a rotor blade. The winglet generally comprises a winglet body, which defines cross-sectional profiles at several radial locations along the winglet body, substantially according to the values ​​illustrated in Table 1. The cross-sectional profiles are connected to define a nominal shape of the winglet body. Furthermore, the nominal shape lies within a bound of ±10% of each length value provided in Table 1, within ±20° of each pitch angle value provided in Table 1, and within ±1° of each toe-in and toe-out angle value provided in Table 1.

[0009] These and other features, aspects, and advantages of the present invention will be better understood with reference to the following description and the accompanying claims. The accompanying drawings, which are included in and form part of this disclosure, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

[0010] A comprehensive and enabling disclosure of the present invention, including its best embodiment, which is directed to a person skilled in the art, is set out in the description which refers to the accompanying figures in which: Fig. 1 a perspective view of an embodiment of a wind turbine with conventional design; Fig. 2 a perspective view of an embodiment of a rotor blade suitable for use in the in Fig.1 illustrated wind turbine suitable, according to aspects of the present subject matter, in particular by illustrating how the rotor blade contains a winglet; Fig. 3 a trailing edge view of the in Fig. 2 illustrated winglets; Fig. 4 a span view of the in Fig. 3 illustrated winglets, photographed on line 4-4; Fig. 5 a local cross-sectional view of a specific cross-sectional profile of the in Fig. 3 illustrated winglets; and Fig. 6 a cross-sectional top view of the in Fig. 4 illustrated winglets, cut along line 6-6.

[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 for the purpose of illustrating the invention, not limiting it. Indeed, it will be obvious to those skilled in the art that various modifications and alterations can be made to the present invention without departing from its scope or essence. For example, features illustrated or described as part of one embodiment can be used in another embodiment to give yet another embodiment. Thus, the intention is that the present invention includes such modifications and alterations as fall within the scope of the appended claims and their equivalents.

[0012] In general, the present subject matter discloses a winglet for a rotor blade of a wind turbine. In particular, the present subject matter discloses a pressure-side winglet with a unique geometric shape. For example, the winglet can be defined in various embodiments by one or more design parameters, including, but not limited to, span radius, chord, axis of attack, sweep, pre-curvature, twist angle, pitch angle, toe-in angle, and radius of curvature. By defining the shape using such design parameters and by using specific ranges of values ​​within such design parameters, it has been found that the disclosed winglet can generally improve the overall performance and efficiency of a wind turbine.

[0013] By referring to the drawings, it is illustrated Fig.Figure 1 shows a conventional wind turbine 10. The wind turbine 10 includes a tower 12 with a nacelle 14 mounted on it. Several rotor blades 16 are mounted on a rotor hub 18, which in turn is connected to a main flange that rotates a main rotor shaft. The energy generation and control components of the wind turbine are housed in the nacelle 14. The view according to Fig. Figure 1 is shown only for illustrative purposes, to place the present invention in an exemplary field of application. It should be understood that the invention is not limited to any particular type of wind turbine configuration.

[0014] Referring to Fig. Figure 2 is a perspective view of an embodiment of a rotor blade 100, which is suitable for use in a wind turbine 10 ( Fig.1) suitable, as illustrated by aspects of the present subject matter. As illustrated, the rotor blade 100 generally includes a blade base 102, which is used to mount the rotor blade 100 to the rotor hub 18 of the wind turbine 10 ( Fig.1) is arranged, and a wingtip 104 is located on the opposite side to the wing root 102. A body 106 of the rotor wing 100 can generally extend from the wing root 102 to the wingtip 104 and can serve as the outer shell of the rotor wing 100. As is generally understood, the body 106 can define an aerodynamic profile, for example by defining a symmetrical or cambered airfoil-shaped cross-section, to enable the rotor wing 100 to capture kinetic energy from the wind using known aerodynamic principles. In itself, the body 106 can generally include a pressure side 108 and a suction side 110 extending between a leading edge 112 and a trailing edge 114.Furthermore, the rotor blade 100 can have a wingspan 116, which defines the overall length of the blade between the blade root 102 and the blade tip 104, and a chord 118, which defines the overall length of the body 106 between the leading edge 112 and the trailing edge 114. As is generally understood, the length of the chord 118 can vary with respect to the wingspan 116, while the rotor blade 100 extends between the blade root 102 and the blade tip 104.

[0015] Furthermore, as will be described in greater detail below, the rotor blade 100 can also include a pressure-side winglet 120 that terminates at the blade tip 104. It should be noted that in various embodiments, the winglet 120 can be manufactured as a separate component from the body 106 and thus configured to be mounted on the body 106 using any suitable means and / or methods known in the art (e.g., using suitable fasteners and / or adhesives). In principle, the winglet 120 can be retrofitted to existing rotor blades 100 by, for example, removing a portion of the existing rotor blade adjacent to the blade tip 104 and replacing such a removed portion with the disclosed winglet 120. Alternatively, the winglet 120 and the body 106 can be integrally formed as a single component.For example, in one embodiment the winglet 120 and the body 106 can be cast together in a common mold.

[0016] For the sake of reference only, it should be noted that the directions X, Y, and Z designated herein are generally defined as the typical directional axes used for conventional straight rotor blades (i.e., rotor blades that do not have a winglet and are not swept, pre-bent, twisted, or the like). Accordingly, the Z direction is along a straight axis (as defined in the Fig. 2, Fig. 3 and Fig. 4 illustrated axis shown) is defined, extending parallel to the span 116 of the rotor wing 100. The X-direction is along a straight axis (as defined by the axis shown in the Fig. 2, Fig. 4 and Fig.The X-axis (as illustrated in Figure 5) is defined and extends perpendicular to the Z-axis, such that, assuming the rotor blade 100 has a straight configuration, the X-axis extends between the leading and trailing edges 112, 114 of the body 106. The Y-direction is along a straight axis (as shown in Figure 5). Fig. 2, Fig. 3 and Fig. 4 illustrated axis shown) defined, which extends perpendicular to the Z and X axes such that, assuming that the rotor blade 100 has a straight configuration, the Y-axis extends between the pressure and suction sides 108, 110 of the body 106. Furthermore, as in Fig. Figure 2 illustrates that the origin of the X, Y and Z axes with respect to the rotor wing 100 is defined such that the positive X direction extends to the trailing edge 114 of the body 106 and the positive Y direction extends to the suction side 110 of the body 106.

[0017] By now focusing on the Fig. 3- Fig. 6. Reference is made to various views of the embodiment of the [item] described in [reference]. Fig. The two illustrated Winglets 120 illustrate aspects of the present subject matter. In particular, they illustrate Fig. 3 a trailing edge view of the in Fig. 2 illustrated winglets 120. Fig. Figure 4 illustrates a span view of the in Fig. 3 illustrated winglets 120, cut at line 4-4. Fig. Figure 5 illustrates a local cross-sectional view of a specific cross-sectional profile of the in Fig. 3 illustrated winglets 120. Also illustrated Fig. 6 a cross-sectional top view of the in Fig. 4 illustrated Winglet 120, cut along line 6-6.

[0018] As particularly in Fig.As illustrated in Figure 3, the disclosed winglet 120 generally has a winglet body 122 extending from a first end 124 located at a junction 126 defined between the winglet 120 and the body 106 to a second end 128 located at the blade tip 104. In general, the winglet body 122 can be configured similarly to the body 106 of the rotor blade 100. For example, the winglet body 122 can generally define an aerodynamic profile, such as a symmetrical or cambered airfoil-shaped cross-section. Thus, the winglet body 122 can also include a pressure side 130 and a suction side 132 extending between a leading edge 134 and a trailing edge 136. It should be noted that in various embodiments, the aerodynamic profile of the winglet body 122 at the junction 126 (i.e.,at the first end 124 of the winglet body 122) can essentially correspond to the aerodynamic profile of the body 106 at the junction 126, so that an essentially smooth and continuous aerodynamic profile can be formed between the winglet 120 and the body 106.

[0019] Furthermore, according to aspects of the present subject matter, the winglet body 122 can also have a unique geometric shape designed to improve the overall efficiency and performance of the rotor blade 100. In particular, due to its unique shape, the disclosed winglet 120 can promote the displacement of vortices at the blade tip 104, thereby reducing peak losses and increasing the power coefficient of the wind turbine 10 ( Fig.1) is increased. The winglet shape is further designed to increase the annual energy yield (AEP) of the wind turbine 10 without increasing loads (e.g., thrust) or the rotor diameter, thereby reducing the cost of the energy generated by the wind turbine 10. In addition, because the winglet 120 is configured as a pressure-side winglet, the clearance between the rotor blade 100 and the tower 12 ( Fig. 1) not reduced.

[0020] In general, the unique shape of the winglet body 122 can be defined by one or more design parameters, including, but not limited to, the span radius 138, the chord 140, the axis of attack 142, the sweep 144, the pre-curve 146, the twist angle 148, the pitch angle 150, the toe-in angle 152, and the radius of curvature 154, 156, all of which are design parameters generally known and understood by those with ordinary knowledge in the field of aerodynamics. For the purposes of this disclosure, one or more of these design parameters may be defined with respect to the interface 126 between the winglet body 122 and the body 106 (i.e., with respect to the first end 124 of the winglet body 122). However, as mentioned above, the revealed winglet 120 can be formed separately from or integrally with the body 106.It should therefore be recognized that the use of the term "joint" need not be limited to embodiments in which the winglet body 122 is produced as a separate component and separately mounted on the body 106. Rather, the term "joint" generally corresponds to the point at which the disclosed winglet shape originates along the span 116 of the rotor wing 100, with the winglet body 122 extending from the joint 126 to the wing tip 104. Thus, in embodiments in which the winglet body 122 and the body 106 are integrally formed, the term "joint" can be used simply to correspond to a reference point from which the shape of the disclosed winglet body 122 is defined.

[0021] As in Fig.As illustrated in Figure 3, the disclosed winglet 120 can generally define a span length or span radius 138, which corresponds to the length of the winglet body 122 along the Z-axis. In particular, the span radius 138 can be defined as the length of the winglet body 120 along a reference line extending parallel to the Z-axis from the connection point 126 to another radial point along the winglet body 122. For example, the total span radius 138 of the winglet body 122, measured from the junction 126 (i.e., the first end 124 of the winglet body 122) to the wingtip 104 (i.e., the second end 128 of the winglet body 122), can be in the range of approximately 2000 millimeters (mm) to approximately 3750 mm, such as from approximately 2500 mm to approximately 3500 mm or from approximately 2750 mm to approximately 3250 mm, or in any other sub-range in between.Alternatively, the span radius 138 can be defined from the first span point along the winglet body 122, which includes a pre-bend 146. For example, as illustrated in Table 1 below, in a particular embodiment of the present product, the pre-bend 146 of the winglet 120 can originate approximately 1000 mm from the joint 126, the joint 126 generally corresponding to a radial point #1. In such an embodiment, the span radius 138 of the winglet 120, measured along the section of the winglet 120 which contains the pre-bend (e.g. from the first span section which contains the pre-bend 146 to the wingtip 104), can be in the range of about 1500 mm to about 2500 mm, such as from about 1750 mm to about 2250 mm or from about 1900 mm to about 2100 mm and in all other partial ranges in between.

[0022] Furthermore, as in the Fig.4 and Fig.Figure 5 illustrates that the winglet 120 defines a chord 140 which essentially corresponds to the length of the winglet body 122 along a reference line extending between the leading and trailing edges 134, 136 of the winglet 120. It should be recognized that in various embodiments, the chord 140 can generally decrease in size along the span radius 138 of the winglet 120 as the winglet body 122 extends from the junction 126 to the wingtip 104. For example, in a particular embodiment of the present article, the chord 140 at the connection point 126 (i.e., at the first end 124 of the winglet body 122) may be located in the range of approximately 750 millimeters (mm) to approximately 1260 mm, such as from approximately 850 mm to approximately 1150 mm or from approximately 950 mm to approximately 1050 mm, or in any other partial range in between, while the chord 140 at the wingtip 104 (i.e.,at the second end 128 of the winglet body 122) in the range of about 35 mm to about 200 mm, such as from about 40 mm to about 100 mm or from about 45 mm to 55 mm or in all other sub-ranges in between.

[0023] Furthermore, the winglet 120 can also include an axis of attack 142, which is defined as a function of the chord 140 at each radial point along the span radius 138 of the winglet 120. As is generally understood, the relative position of each cross-sectional profile to the axis of attack 142 can be used to control the shape of the leading and trailing edges 134, 136 of the winglet 120 and can also be used as the reference point for defining the twist angle 148 of the winglet 120. As in Fig.As illustrated in Figure 5, the axis of attack 142 can, in various embodiments, generally correspond to a point along the chord 140 of a cross-sectional profile of the winglet 120 at a specific radial location along the winglet body 122 and be located at a distance 158 from the leading edge 134 of the winglet 120, which corresponds to a percentage of the chord 140. For example, in one embodiment, the axis of attack 142 can be arranged at a distance 158 from the leading edge 134 in the range of approximately 22% of the chord 140 at any radial point along the winglet body 122 to approximately 38% of the chord 140 at any radial point along the winglet body 122, such as from approximately 25% of the chord 140 to approximately 35% of the chord 140 or from approximately 28% of the chord 140 to approximately 32% of the chord 140 or in all other partial ranges in between.

[0024] Furthermore, the shape of the winglet body 122 can also be defined on the basis of the displacement or sweep 144 of the winglet 120 along the X-axis. In particular, as in Fig.Figure 4 illustrates that the sweep 144 is measured along a reference line extending parallel to the X-axis, and it can correspond to the distance along such a reference line between a given chord point of the winglet body 122 at the junction 126 (i.e., at the first end 124 of the winglet body 122) and a corresponding chord point at another radial location along the winglet body 122. For example, the size of the sweep 144 of the winglet 120 at a particular radial location along the winglet body 122 can be defined as the distance to a quarter chord point 160 at the junction 126 (i.e., a distance to the leading edge 134 corresponding to 25% of the chord 140 at the junction 126) to a quarter chord point at that particular radial location (i.e., a distance to the leading edge 134 corresponding to 25% of the chord 140 at the particular radial location).Thus, in various embodiments, the total magnitude of the sweep 144 of the winglet 120 (defined from a quarter-chord point 160 at the junction to a quarter-chord point 162 at the wingtip 104) can lie in the range of approximately 580 mm to approximately 970 mm, such as from approximately 650 mm to approximately 850 mm or from approximately 700 mm to approximately 800 mm, or in any other intermediate range. It should be noted that a positive value for the sweep 144 can generally shift the leading edge 134 of the winglet 120 in the positive X-direction, as shown in [reference missing]. Fig. Figure 4 illustrates this. It should also be recognized that in alternative embodiments, the sweep 140 can be defined in relation to any other suitable chord points, such as 35% chord points, 50% chord points, 75% chord points, and the like.

[0025] Furthermore, as in Fig.Figure 3 illustrates that the shape of the winglet body 122 can also be defined based on the height or magnitude of the pre-bending 146 of the winglet 120. The pre-bending 146 can generally be measured along a reference line extending parallel to the Y-axis and can correspond to the distance along such a reference line between a specific chord point of the winglet body 122 at the junction 126 (i.e., at the first end 124 of the winglet body 122) and a corresponding chord point at another radial location along the winglet body 122. For example, the magnitude of the pre-bending 146 at a specific radial location along the winglet 120 can be defined from the trailing edge 136 of the winglet body 122 at the junction 126 to the trailing edge 136 of the winglet body 122 at that specific radial location.Thus, in various embodiments, the total size of the pre-bending 146 of the winglet 120 (defined from the trailing edge 136 at the joint 126 to the trailing edge 136 at the wingtip 104) can lie in the range of approximately 1500 mm to approximately 3450 mm, such as from approximately 1750 mm to approximately 3250 mm or from approximately 2500 mm to approximately 3000 mm, or in any other partial range in between. It should be noted that a positive value for the pre-bending 136 can generally be located towards the pressure side 130 of the winglet 120 (i.e., in the negative Y-direction).

[0026] Furthermore, the winglet 120 can also be twisted about the axis of attack 142, thereby defining a twist angle 148 for setting the angle of attack of the winglet relative to the wind direction. As in Fig.As illustrated in Figure 5, the twist angle 148 at each cross-sectional profile of the winglet 120 can generally be defined with respect to the leading edge 134 of the winglet 120 and correspond to the angle between a reference line extending parallel to the chord 140 and a horizontal reference line extending through the axis of attack 142 at a twist angle 148 of 0°. In various embodiments, the twist angle 148 of the angle 120 can vary along the span radius 138. For example, in a particular embodiment of the present article, the twist angle 148 at the junction 126 (i.e., at the first end 124 of the winglet body 122) can be in the range of approximately -1.1° to approximately -1.9°, such as approximately -1.3° to approximately -1.7° or approximately -1.4° to approximately -1.6°, or in any other partial range in between. Likewise, the twist angle 148 at the wingtip can be 104 (i.e.at the second end 128 of the winglet body 122) in the range of approximately -6.7° to approximately -11.3°, such as from approximately -7.5° to approximately -10.5° or from approximately -8.5° to approximately -10.5°, and in all other sub-ranges in between. It should be recognized that a negative value for the twist angle 148 generally corresponds to a twist of the winglet 120 away from the sail position. In other words, a negative value for the twist angle 148 can twist the leading edge 134 in such a way that the local angle of attack of the winglet 120 is increased.

[0027] Furthermore, the winglet 120 can also define an inclination angle 150, which corresponds to the rotation of the winglet body 122 about each local chord 140 along the span radius 138. In particular, as in Fig.Figure 3 illustrates that the inclination angle 150 at a specific radial location along the winglet body 122 is defined as the angle between a reference line extending parallel to the Z-axis and a reference line extending tangentially to the winglet 120 at that specific radial location. For example, in various embodiments, the inclination angle 150 at the wingtip 104 (i.e., at the second end 128 of the winglet body 122) may be in the range of approximately 64° to approximately 108°, such as approximately 70° to approximately 100° or approximately 80° to approximately 90°. It should be recognized that a positive value for the inclination angle 150 produces a pressure-side winglet, as illustrated in the embodiment shown.

[0028] Furthermore, and as in Fig.As illustrated in Figure 6, the winglet 120 further defines a toe-in angle 152, which corresponds to the rotation of the winglet 120 about the Y-axis at any radial point along the winglet body 122. Thus, the toe-in angle 152 for a particular radial point along the winglet body 122 can generally be defined as the angle between a reference line extending parallel to the X-axis and a reference line extending parallel to the chord 140 at that radial point. Accordingly, in various embodiments, the toe-in angle 122 at the wingtip 104 (i.e., at the second end 128 of the winglet body 122) can be in the range of approximately 0.62° to approximately 1.04°, such as approximately 0.70° to approximately 0.90° or approximately 0.78° to approximately 0.88°, or in any other partial range in between. It should be recognized that a positive toe-in angle 152 generally moves the leading edge 134 of the winglet 120 radially outwards (i.e.from the wing root 102 of the rotor wing 100 away along the Z-axis).

[0029] Furthermore, the winglet 120 can also have a radius of curvature 154, 156, which generally defines the entire curvature of the winglet body 122 in the ZY plane. For example, the winglet 120, as in Fig.Figure 3 illustrates defining a first radius of curvature 154 in the Z-direction and a second radius of curvature 156 in the Y-direction. It should be noted that in various embodiments, the first radius of curvature 154 can be equal to the second radius of curvature 156. Alternatively, the first radius of curvature 154 can differ from the second radius of curvature 156. For example, in one embodiment, the curvature of the winglet body 122 can be defined by a curve fitting having a first radius of curvature 154 in the range of about 1500 mm to about 2500 mm, such as from about 1750 mm to about 2250 mm or from about 1950 mm to about 2050 mm or in any other partial range in between, and a second radius of curvature 156 in the range of about 1200 mm to about 2000 mm, such as from about 1400 mm to about 1800 mm or from about 1550 mm to about 1650 mm or in any other partial range in between.It should be recognized that the curvature can generally be defined by any suitable curve fitting, such as an ellipse, a parabola fitting, an exponential fitting, or any other suitable type of curve fitting.

[0030] Furthermore, in a particular embodiment of the present subject matter, a nominal geometric shape of the winglet body 122 can be defined by the values ​​provided in Table 1. As mentioned above, the span radius 138 of the winglet 120 can generally be defined with respect to the connection point 126 between the winglet body 122 and the body 106 (i.e., the first end 124 of the winglet body 122) and extend from such a connection point 126 to the wingtip 104 (i.e., the first end 124 of the winglet body 122). Thus, as illustrated in Table 1, the span radius 138 can be 0.00 mm at radial point #1 (i.e. defined at the junction 126 or the first end 124), while the span radius 138 increases up to radial point #15 (i.e. defined at the wingtip 104 or the second end 128).In addition to the span radius 138, values ​​for the chord 140, the axis of attack 142, the sweep 144, the pre-bending 146, the twist angle 148, the tilt angle 150 and the toe-in angle 152 of the winglet 120 are provided at each radial point in order to generally provide a complete nominal shape of the winglet body 122. TABLE 1 Radial point Span radius (mm) chord (mm) Axis of attack (% of chord) Arrow angle (mm) Pre-bending (mm) Rotation angle (degrees) Angle of inclination (degrees) Angle of advantage (degrees) 1 0,00 1007,60 0,31 0,00 0,00 -1,48 0,00 0,00 2 782,00 977,00 0,31 0,00 0,00 -1,63 0,00 0,00 3 891,00 973,48 0,31 0,00 0,00 -1,63 0,00 0,00 4 1000,00 969,96 0,31 0,00 0,00 -1,63 0,00 0,00 5 1235,73 954,20 0,31 4,19 22,94 -1,63 0,12 0,00 6 1536,45 917,18 0,30 28,71 70,74 -1,62 4,75 0,03 7 1848,06 857,10 0,30 75,63 156,29 -1,66 12,93 0,09 8 2166,64 778,10 0,30 142,65 301,76 -1,94 24,18 0,17 9 2472,62 684,33 0,30 226,03 523,24 -2,68 37,88 0,26 10 2734,41 579,91 0,30 319,39 823,85 -3,58 53,56 0,37 11 2914,99 468,99 0,30 413,82 1188,87 -5,02 70,98 0,47 12 2982,63 355,71 0,30 500,09 1584,82 -6,52 86,36 0,57 13 3007,78 244,21 0,30 580,93 1981,94 -7,81 86,36 0,67 14 3032,94 138,63 0,30 657,69 2376,83 -8,70 86,36 0,75 15 3056,15 50,00 0,30 722,40 2741,33 -9,00 86,36 0,83

[0031] It should be recognized by experts in the field that each radial location (radial locations #1-15), as provided in Table 1, generally corresponds to a specific location along the winglet body 122 where a cross-sectional profile (e.g., similar to that shown in Fig.The cross-sectional profile of the winglet 120 (illustrated in Figure 5) is defined using the specified values. Accordingly, it should be recognized that the disclosed winglet 120 can be physically manufactured and / or graphically modeled using the values ​​provided in Table 1 to define the shape and / or orientation of the cross-sectional profiles at each radial location. Such cross-sectional profiles can then be raised, joined, and / or otherwise connected to one another using any suitable means known in the art (e.g., by connecting all cross-sectional profiles with smooth, continuous arcs using suitable computer modeling or drawing software) to define the overall winglet shape.

[0032] Furthermore, the values ​​provided in Table 1 for defining the shape of the winglet body 122 are presented with two decimal places. However, it is assumed that the values ​​defining the winglet shape can be varied without impairing the advantages achieved by the disclosed winglet 120. Consequently, the values ​​given in Table 1 apply to a nominal winglet shape. It is therefore recognized that positive or negative (+ / -) deviations of any of the values ​​provided in Table 1, including but not limited to + / - deviations for manufacturing tolerances and other design considerations, may be created without departing from the scope of this disclosure. For example, in one embodiment, a tolerance of approximately + / -10% of the length values ​​(i.e.,The wingspan radius 138, chord 140, axis of attack 142, sweep 144, and camber 146 at each radial location, a tolerance of approximately + / -20° for the pitch angle values ​​at each radial location, and a tolerance of approximately + / -1° for the other angle values ​​(i.e., twist angle 148 and toe-in angle 152) at each radial location define an airfoil for the winglet shape disclosed in Table 1. In another embodiment, the airfoil for the winglet shape disclosed in Table 1 can be defined by a tolerance of approximately + / -5% of the length values ​​at each radial location, a tolerance of approximately + / -10° for the pitch angle values ​​at each radial location, and a tolerance of approximately + / -0.5° for the other angle values ​​at each radial location.

[0033] It should further be recognized that the nominal winglet shape, as provided above, can be geometrically scaled up or down for use with rotor blades 100 having any suitable dimensions and / or configurations. Accordingly, the values ​​provided in Table 1 at each radial point can be a function of one or more constants. That is to say, depending on the specific design parameter being scaled to create an "upscaled" or "downscaled" version of the disclosed winglet 120 while maintaining the winglet shape disclosed herein, the specified values ​​can be multiplied by the same constant or by different constants, or divided by the same constant or by different constants. This scaling could be used to adapt the winglet 120 to a larger or smaller blade.For example, in one embodiment, one or more of the length values ​​(i.e., span radius 138, chord 140, angle of attack 142, sweep 144 and pre-bending 146) can be multiplied by or divided by a first constant, while one or more of the angle values ​​(i.e., twist angle 148, tilt angle 150 and toe-in angle 152) can be multiplied by or divided by a second constant.

[0034] Furthermore, as an alternative to defining the shape of the winglet body using all the values ​​provided in Table 1, the winglet shape can also be defined by using the table values ​​for a combination of two or more design parameters at each radial location. For example, the disclosed winglet 120 in various embodiments can be easily defined at each radial location using the values ​​for the chord 140 and the twist angle 148, as provided in Table 1. In such embodiments, the values ​​for the chord 140 can generally be varied by + / -25% at each radial location, and the values ​​for the twist angle 148 can generally be varied by + / -2.5° at each radial location to accommodate manufacturing tolerances and other design considerations.In other embodiments, various other combinations of design parameters can be used to define the winglet 120, for example by using the values ​​for sweep 144 and pre-bending 146 at each radial point, or by using the values ​​for sweep 144 and tilt angle 150 at each radial point, wherein the values ​​of such combinations have a suitable + / - deviation to account for manufacturing tolerances and other design considerations.

[0035] Furthermore, it should be recognized that, in addition to the advantages gained through the unique shape of the disclosed winglet 120, further advantages can be obtained if the winglet 120 has a separate component configured to be attached separately to the body 106 of the rotor blade 100. In particular, a modular configuration can enable the winglet 120 to be manufactured and stored easily and efficiently, thereby reducing overall production costs. Moreover, the winglet 120, in the form of a separate component, can be easily transported from the manufacturing facility to the field and mounted on the rotor blade 100 without the need to remove such a rotor blade 100 from the wind turbine 10.

[0036] This written description uses examples to disclose the invention, including its best embodiment, and also to enable any person skilled in the art to put the invention into practice, including creating and using any devices or systems and carrying out any methods contained therein. The patentable scope of the invention is defined by the claims and may include further examples that might occur to persons skilled in the art. Such further examples shall be within the scope of the claims if they contain structural elements that do not differ from the literal meaning of the claims or if they contain equivalent structural elements with differences that are insignificant compared to the literal meaning of the claims.

[0037] A winglet 120 for a rotor wing is disclosed. The winglet 120 can generally include a winglet body 122 extending between a first end 124 and a second end 128. The winglet body 122 can define a sweep 144 and can have a curvature defined by a curve fit that includes a first radius of curvature 154 and a second radius of curvature 156. The sweep 144 between the first end 124 and the second end 128 can be in the range of approximately 580 mm to approximately 970 mm. Furthermore, the first radius of curvature 154 can be in the range of approximately 1500 mm to approximately 2500 mm, and the second radius of curvature 156 can be in the range of approximately 1200 mm to approximately 2000 mm. Reference symbol list 10 wind turbines 12 Tower 14 gondolas 16 rotor blades 18 Rotor hub 100 rotor blades 102 wing foot 104 wingtip 106 bodies 108 Printed side (of the body) 110 Suction side (of the body) 112 Front edge (of the body) 114 Trailing edge (of the body) 116 wingspan 118 tendon 120 Pressure-side winglet 122 Winglet bodies 124 First End 126 liaison point 128 Second Ending 130 Print side (of the winglet) 132 Suction side (of the winglet) 134 Leading edge (of the winglet) 136 Trailing edge (of the winglet) 138 Span radius 140 tendon 142 Axle of inclination 144 Arrow 146 Pre-bending 148° angle of rotation 150° tilt angle 152 toe angle 154 Radius of curvature (R1) 156 Radius of curvature (R2) 158 Distance to the axis of inclination 160 quarter (25%) tendon point 162 Quarter (25%) tendon point

Claims

[1] Winglet (120) for a rotor blade (100) which has: a winglet body (122) extending between a first end (124) and a second end (128), wherein the winglet body (122) defines a sweep (144) and has a curvature defined by a curve fit including a first radius of curvature (154) and a second radius of curvature (156), wherein the sweep (144) defined between the first end (124) and the second end (128) is in the range of about 580 mm to about 970 mm, wherein the first radius of curvature (154) is in the range of about 1500 mm to about 2500 mm and the second radius of curvature (156) is in the range of about 1200 mm to about 2000 mm. [2] Winglet (120) according to claim 1, wherein the winglet body (122) further defines a chord (140), wherein the chord (140) is located at the first end (124) in the range of about 750 mm to about 1260 mm. [3] Winglet (120) according to any one of the preceding claims, wherein the winglet body (122) further defines a chord (140), wherein the chord (140) is located at the second end (128) in the range of about 35 mm to about 200 mm. [4] Winglet (120) according to any one of the preceding claims, wherein the winglet body (122) further defines a toe-in angle (152), wherein the toe-in angle (152) at the second end (128) is in the range of about 0.62° to about 1.04°. [5] Winglet (120) according to any one of the preceding claims, wherein the winglet body (122) further defines a span radius (138) and a pre-bend (146), wherein the span radius (138) of a section of the winglet body (122) includes a pre-bend (146) which is in the range of about 1500 mm to about 2500 mm. [6] Winglet (120) according to any one of the preceding claims, wherein the winglet body (122) further defines a twist angle (148), wherein the twist angle (148) at the second end (128) is in the range of about -6.7° to about -11.3°. [7] Winglet (120) according to any one of the preceding claims, wherein the winglet (120) further defines an angle of inclination (150), wherein the angle of inclination (150) at the second end (128) is in the range of about 64° to about 108°. [8] Winglet (120) according to any one of the preceding claims, wherein the winglet body (122) further defines a pre-bend (146), wherein the pre-bend (146), which is defined between the first end (124) and the second end (128), is in the range of about 1500 mm to about 3450 mm. [9] Winglet (120) for a rotor blade (100) which has: a winglet body (122) extending between a first end (124) and a second end (128) and containing several radial locations between the first and second ends (124, 128), wherein the winglet body (122) defines a chord (140) and a twist angle (148) at each of the several radial locations substantially according to the values ​​for the chord (140) and the twist angle (148) shown in Table 1, wherein each of the values ​​shown in Table 1 for the chord (140) can be varied by + / -25% and each of the values ​​shown in Table 1 for the twist angle (148) can be varied by + / -2.5°. [10] Winglet (120) according to claim 9, wherein the winglet body (122) further defines an angle of inclination (150), wherein the angle of inclination (150) at the second end (128) is in the range of about 64° to about 108°. [11] Winglet (120) according to any one of claims 9-10, wherein the winglet body (122) further defines a pre-bend (146), wherein the pre-bend (146) defined between the first end (124) and the second end (128) is in the range of about 1500 mm to about 3450 mm. [12] Winglet (120) according to any one of claims 9-11, wherein the winglet body (122) further defines a span radius (138) and a pre-bend (146), wherein the span radius (138) of a section of the winglet body (122) containing the pre-bend (146) is in the range of about 1500 mm to about 2500 mm. [13] Winglet (120) according to any one of claims 9-12, wherein the winglet (120) further defines a sweep (144), wherein the sweep (144) defined between the first end (124) and the second end (128) is in the range of about 580 mm to about 970 mm. [14] Winglet (120) according to any one of claims 9-13, wherein the winglet (120) further defines a toe-in angle (152), wherein the leading angle (152) at the second end (128) is in the range of about 0.62° to about 1.04°. [15] Winglet (120) for a rotor blade (100) which has: a winglet body (122) wherein the winglet body (122) defines cross-sectional profiles at several radial locations along the winglet body (122) substantially according to the values ​​shown in Table 1, wherein the cross-sectional profiles are connected to define a nominal shape of the winglet body (122), wherein the nominal shape is within a shell within + / -10% of each length value provided in Table 1, within + / -20° with respect to each value provided in Table 1 for the pitch angle (150) and within + / -1° with respect to each value provided in Table 1 for the toe angle (152) and the twist angle (148).

Images