Tungsten-based corrosion-resistant leading edge protective cover for a rotor blade

Abstract

A rotor blade assembly for a wind turbine comprises at least one rotor blade having a surface defining a pressure side, a suction side, a leading edge and a trailing edge extending between a blade tip and a blade root. The surface is composed of a polymer composite material. The rotor blade assembly further comprises a protective cover arranged adjacent to one or more of the surfaces of the rotor blade so as to cover at least a portion of the one or more surfaces of the rotor blade. The protective cover comprises a main body defining an overall length. Furthermore, at least a first section of the protective cover is composed of a tungsten-based metal. Thus, the protective cover is configured to reduce corrosion of the rotor blade caused by particle or liquid impact and to resist erosion of the rotor blade caused thereby.

Description

TECHNICAL FIELD

[0001] The present disclosure relates generally to rotor blades, and more particularly to tungsten-based leading edge protection covers for rotor blades to protect the rotor blades from corrosion and / or erosion. BACKGROUND

[0002] Wind energy is considered one of the cleanest and most environmentally friendly sources of energy available today, 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 the wind's kinetic energy using known airfoil principles. The rotor blades transmit the kinetic energy in the form of rotational energy to 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 that can be deployed to a utility grid.

[0003] During operation of a wind turbine, the rotor blades can be subjected to a wide variety of environmental conditions. In many cases, such as when the wind turbine is located in a coastal or desert region or offshore, the rotor blades can be subjected to environmental conditions including abrasive materials such as sand, raindrops, or sea water. The interaction of these abrasive materials with the rotor blades can cause corrosion of portions of the rotor blades. In particular, the leading edge of the rotor blades can be very susceptible to corrosion. Corrosion of various portions of the rotor blades limits the maximum rotational speed of the rotor blades, and thus the power output of the wind turbine. More particularly, leading edge corrosion can cause a loss of surface roughness and / or chord loss, thus causing performance losses and durability problems over time.

[0004] Accordingly, an improved protection cover for rotor blades that prevents corrosion and / or erosion would be welcome in the art. In view of the above, the present disclosure is directed to a tungsten-based metal leading edge cover for a wind turbine rotor blade that protects the blade from corrosion. SUMMARY

[0005] Aspects and advantages of the application will be set forth in part in the following description, or can become apparent to those skilled in the art by practice of the application.

[0006] In an aspect, the present disclosure is directed to a rotor blade assembly. The rotor blade assembly includes at least one rotor blade having a surface defining a pressure side, a suction side, a leading edge, and a trailing edge extending between a blade tip and a blade root. The surface is composed of a polymer composite material. The rotor blade assembly further includes a protective cover disposed adjacent to one or more of the surfaces of the rotor blade so as to cover at least a portion of the one or more surfaces of the rotor blade. The protective cover includes a main body defining an overall length. Further, at least a first section of the protective cover is composed of a tungsten-based metal. As such, the protective cover is configured to reduce corrosion of the rotor blade and resist erosion of the rotor blade caused by particle or liquid impacts.

[0007] In embodiments, the tungsten-based metal can be, for example, elemental tungsten, tungsten titanium, tungsten silicon, tungsten nickel, or tungsten aluminum. Further, in embodiments, the protective cover can cover at least a portion of the leading edge of the rotor blade. In another embodiment, the tungsten-based metal can be formed into at least one of a foil, one or more strips, one or more plates, or one or more sheets.

[0008] In particular embodiments, the protective cover can be secured to one or more of the surfaces via an adhesive.

[0009] In further embodiments, the protective cover can have a clip-on spring configuration that clips onto one or more of the surfaces of the rotor blade. In such embodiments, a thickness of a cross-section of the clip-on spring configuration varies along at least a portion of the overall length of the protective cover. In further embodiments, the clip-on spring configuration can also include at least one of an inner thickened edge or an outer thickened edge.

[0010] In alternative embodiments, the protective cover can have a clip-in configuration that is at least partially secured within an internal cavity of the rotor blade. In such embodiments, the clip-in configuration can include a protruding leading edge portion and an opposing flange. More particularly, in embodiments, the opposing flange can be secured to an inner surface of one or more of the surfaces of the rotor blade within the internal cavity of the rotor blade.

[0011] In several embodiments, at least a second section of the protective cover can be composed of a polymer material.

[0012] In yet another embodiment, the protective cover can be integrated with a lightning protection system of the rotor blade.

[0013] In another aspect, the present disclosure is directed to a method for manufacturing a rotor blade assembly. The method includes providing at least one rotor blade having a surface defining a pressure side, a suction side, a leading edge, and a trailing edge extending between a blade tip and a blade root. Further, the surface is composed of a polymer composite material. The method also includes forming a protective cover having a shape corresponding to a curvature of one or more of the surfaces of the rotor blade. A first section of the protective cover is formed of a tungsten-based metal, and a second section of the protective cover is formed of a different material. Further, the method includes arranging the protective cover adjacent to one or more of the surfaces of the rotor blade so as to cover at least a portion of the one or more surfaces of the rotor blade. Further, the method includes securing the protective cover to the one or more of the surfaces of the rotor blade such that the first section of the protective cover formed of the tungsten-based metal is arranged adjacent to the blade tip. As such, the protective cover is configured to reduce corrosion of the rotor blade caused by particle or liquid impact and to resist erosion of the rotor blade caused thereby.

[0014] In embodiments, forming the protective cover can include at least one of sheet press forming, laser sheet forming, additive manufacturing, electroforming, cold spraying, rolling, surface hardening, coating deposition, sintering, or similar methods, and combinations thereof.

[0015] In another embodiment, the tungsten-based metal can include elemental tungsten, tungsten titanium, tungsten silicon, tungsten nickel, or tungsten aluminum, for example, and the different material can include a polymer material, a shape memory alloy, a nickel alloy such as nickel-chromium or nickel-chromium-molybdenum as examples, an aluminum alloy, a titanium alloy, a steel alloy, or any other suitable material.

[0016] In further embodiments, securing the protective cover to the one or more of the surfaces of the rotor blade can include securing the protective cover to the one or more of the surfaces of the rotor blade via at least one of an adhesive or a mechanical joint. For example, in embodiments, the mechanical joint can include an over-clamp spring configuration, an under-clamp configuration, or one or more fasteners.

[0017] Accordingly, where the mechanical joint is an over-clamp configuration, the method can include forming a thickness of a cross-section of the over-clamp spring configuration to vary along at least a portion of an overall length of the protective cover via additive manufacturing, electroforming, cold spraying, or combinations thereof.

[0018] In further embodiments, the method can also include forming at least one additional feature onto the protective cover via at least one of additive manufacturing, electroforming, cold spraying, rolling, surface hardening, or similar methods, and combinations thereof. In such embodiments, the additional feature(s) can include an internally thickened edge, an externally thickened edge, one or more flanges, an aerodynamic surface feature, or any other suitable feature.

[0019] In another embodiment, the inner clip configuration can include a protruding leading edge portion and an opposing flange. In such embodiments, the method can include forming the leading edge portion from a first material and forming the opposing flange from a second material, where the first material and the second material are different, and securing the opposing flange to an inner surface of one or more of the surfaces of the rotor blade within the inner cavity of the rotor blade.

[0020] In yet another additional embodiment, the method can include integrating the protective cover with the lightning protection system of the rotor blade, for example via rivets or bolts. It should be appreciated that the rotor blade can also include any of the additional features described herein.

[0021] In yet another aspect, the disclosure is directed to a protective cover for placement adjacent to one or more surfaces of a rotor blade so as to cover at least a portion of the one or more surfaces of the rotor blade. The protective cover includes a body defining an overall length, where at least a first section of the protective cover is composed of a single tungsten. Further, the protective cover is configured to reduce corrosion of the rotor blade caused by particle or liquid impact and to resist erosion of the rotor blade caused thereby.

[0022] These and other features, aspects, and advantages of the present application 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 application and, together with the description, serve to explain the principles of the application. BRIEF DESCRIPTION OF DRAWINGS

[0023] A complete and enabling disclosure of the application, including its best mode, directed to those of ordinary skill in the art follows in the specification accompanied by the appended claims in reference to the attached drawings, wherein:

[0024] Figure 1 illustrates a perspective view of one embodiment of a wind turbine in accordance with the present disclosure;

[0025] Figure 2 illustrates a perspective view of one embodiment of a rotor blade assembly in accordance with the present disclosure;

[0026] Figure 3 illustrates a cross-sectional view of one embodiment of a rotor blade assembly in accordance with the present disclosure;

[0027] Figure 4 illustrates a cross-sectional view of one embodiment of a protective cover for a rotor blade assembly in accordance with the present disclosure;

[0028] Figure 5 illustrates a cross-sectional view of another embodiment of a protective cover for a rotor blade assembly in accordance with the present disclosure;

[0029] Figure 6a cross-sectional view of another embodiment of a protective cover for a rotor blade assembly according to the present disclosure is illustrated;

[0030] Figure 7 a cross-sectional view of another embodiment of a rotor blade assembly according to the present disclosure is illustrated;

[0031] Figure 8 a cross-sectional view of another embodiment of a protective cover for a rotor blade assembly according to the present disclosure is illustrated;

[0032] Figure 9 a cross-sectional view of a rotor blade surface of a rotor blade of a rotor blade assembly according to the present disclosure is illustrated;

[0033] Figure 10 a flowchart of one embodiment of a method for manufacturing a rotor blade assembly for a wind turbine is illustrated.

[0034] Figure 11 a perspective view of one embodiment of a protective cover for a rotor blade assembly according to the present disclosure is illustrated;

[0035] Figure 12 a perspective view of another embodiment of a protective cover for a rotor blade assembly according to the present disclosure is illustrated;

[0036] Figure 13 a perspective view of another embodiment of a protective cover for a rotor blade assembly according to the present disclosure is illustrated; and

[0037] Figure 14 a perspective view of another embodiment of a protective cover for a rotor blade assembly according to the present disclosure is illustrated. DETAILED DESCRIPTION

[0038] Reference will now be made in detail to embodiments of the application, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the application and not as a limitation of the application. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present application without departing from the scope or spirit of the application. 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 application covers such modifications and variations as come within the scope of the appended claims and their equivalents.

[0039] Reference will now be made to the drawings, wherein Figure 1The illustration shows a wind turbine 10 with a conventional construction. As shown, the wind turbine 10 includes a tower 12 with a nacelle 14 mounted thereon. A plurality of rotor blades 16 are mounted to a rotor hub 18, which in turn is connected to a main flange of a rotating main rotor shaft (not shown). The wind turbine power generation and control components are typically housed within the nacelle 14. Figure 1 The views are provided for illustrative purposes only to place the invention within an exemplary field of use. It should be understood that the invention is not limited to any particular type of wind turbine construction.

[0040] Now for reference Figure 2 The illustration shows the following according to the present disclosure. Figure 1 A perspective view of one of the rotor blades 16. As shown, the rotor blade may include a surface defined between a leading edge 26 and a trailing edge 28 and extending from the blade tip 32 to the pressure side 22 of the blade root 34 (see, for example, [reference needed]). Figure 3 The rotor blade 16 may include a plurality of individual blade segments aligned end-to-end from the blade tip 32 to the blade root 34. Each of the individual blade segments may be uniquely configured such that the plurality of blade segments define a complete rotor blade 16 having a designed aerodynamic profile, length, and other desired characteristics. For example, each of the blade segments may have an aerodynamic profile corresponding to the aerodynamic profile of an adjacent blade segment. Thus, the aerodynamic profiles of the blade segments may form a continuous aerodynamic profile of the rotor blade 16. Alternatively, the rotor blade 16 may be formed as a single integral blade having a designed aerodynamic profile, length, and other desired characteristics.

[0041] Furthermore, in an exemplary embodiment, the rotor blade 16 may be curved. Bending of the rotor blade 16 may require bending the rotor blade 16 in a generally flapwise direction and / or in a generally edgewise direction. The flapwise direction can be generally interpreted as the direction in which aerodynamic lift acts on the rotor blade 16 (or the opposite direction). The edgewise direction is generally perpendicular to the flapwise direction. The flapwise curvature of the rotor blade 16 is also referred to as pre-bending, and the edgewise curvature is also referred to as sweeping. Therefore, the curved rotor blade 16 may be pre-bent and / or swept. Bending allows the rotor blade 16 to better withstand flapwise and edgewise loads during operation of the wind turbine 10, and also provides clearance between the rotor blade 16 and the tower 12 during operation of the wind turbine 10.

[0042] The rotor blades 16 can be formed substantially of a polymer composite material, such as a thermoset or thermoplastic material that can be optionally reinforced. Thermoset materials generally encompass a plastic material or polymer that is inherently irreversible. For example, once cured, a thermoset material cannot be readily remolded or returned to a liquid state. As such, after initially being molded, a thermoset plastic material is generally resistant to heat, erosion, and / or creep. Exemplary thermoset materials as described herein can include, but are not limited to, some polyesters, some polyurethanes, esters, epoxies, or any other suitable thermoset material.

[0043] In contrast, thermoplastic materials generally encompass a plastic material or polymer that is inherently reversible. For example, a thermoplastic material typically becomes pliable or moldable when heated to a certain temperature and returns to a more rigid state upon cooling. Further, thermoplastic materials can include amorphous thermoplastic materials and / or semi-crystalline thermoplastic materials. For example, some amorphous thermoplastic materials can include, but are not limited to, styrenes, vinyls, cellulosics, polyesters, acrylics, polysulfones, and / or imides. More specifically, exemplary amorphous thermoplastic materials can include polystyrene, acrylonitrile-butadiene-styrene (ABS), polymethyl methacrylate (PMMA), glycolized polyethylene terephthalate (PET-G), polycarbonate, polyvinyl acetate, amorphous polyamide, polyvinyl chloride (PVC), polyvinylidene chloride, polyurethane, or any other suitable amorphous thermoplastic material. Additionally, exemplary semi-crystalline thermoplastic materials can include, but are not limited to, polyolefins, polyamides, fluoropolymers, ethyl-methyl acrylate, polyesters, polycarbonates, and / or acetals. More specifically, exemplary semi-crystalline thermoplastic materials can include polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polypropylene, polyphenylene sulfide, polyethylene, polyamide (nylon), polyether ketone, or any other suitable semi-crystalline thermoplastic material.

[0044] As in Figures 2 to 13The illustrated, the present disclosure can also be directed to a rotor blade assembly 100 and a method of manufacturing the same. The rotor blade assembly 100 can be suitable for use in a number of applications such as wind turbines, helicopters, engines, propellers, hovercraft, etc. For example, as shown, the rotor blade assembly 100, as discussed above, includes a rotor blade 16 of a wind turbine 10. Further, the rotor blade assembly 100 includes a protective cover 110 configured to reduce corrosion of the rotor blade caused by particulate or liquid impact, such as abrasive environmental conditions including, for example, sand, raindrops, and / or sea water, and to resist erosion of the rotor blade caused thereby. Thus, the protective cover uniquely combines high resistance to erosive degradation when the rotor blade is exposed to an environment containing erosive substances, fog, mist, water, etc. Further, as shown, the protective cover 110 is disposed adjacent to one or more of the surfaces of the rotor blade 16 so as to cover at least a portion of one or more surfaces of the rotor blade 16. For example, as shown in Figure 2 the protective cover 110 can cover at least a portion of the leading edge 26 of the rotor blade 16. In such embodiments, the protective cover 110 can extend at least partially onto the pressure side 22 and / or the suction side 24, as desired to provide suitable corrosion protection. Additionally, or alternatively, the protective cover 110 can be configured on any suitable one or more surfaces of the rotor blade 16, such as the pressure side 22, the suction side 24, the trailing edge 28, the tip 32, and / or the root 34.

[0045] In further embodiments, the protective cover 110 can be configured on only a portion of the rotor blade 16 substantially in the spanwise direction along the length of the rotor blade. For example, the protective cover 110 can be configured substantially on the outer half of the length of the rotor blade 16, or in exemplary embodiments, the protective cover 110 can be configured substantially on the outer third of the length of the rotor blade 16 (in other words, substantially half or a third of the length of the rotor blade 16 including the tip 32). Thus, the protective cover 110 can extend substantially along the entire outer half of the rotor blade 16 or substantially along the entire outer third of the rotor blade 16 substantially in the spanwise direction.

[0046] It should be appreciated, however, that the present disclosure is not limited to the protective cover 110 being configured on or extending through only a portion of the spanwise or chordwise length of the rotor blade 16. Rather, any configuration of the protective cover 110 on any portion of the length of the rotor blade 16 is within the scope of the present disclosure.

[0047] Further, the protective cover 110 can be formed from a single piece of material or be composed of multiple segments. For example, as shown in Figure 2As shown in the middle view, the protective cover 100 is formed from a plurality of segments. More specifically, as shown, the plurality of segments can include (at least) a first segment 114 and a second segment 116. Thus, the individual segments can be formed from different materials or the same material. In particular embodiments, the first segment 114 can be composed of a tungsten-based metal, such as elemental tungsten (which can include pure elemental tungsten), for example. As used herein, "pure elemental tungsten" refers to elemental tungsten of high purity, up to 100% purity, but does not necessarily require 100% purity. Thus, it should be understood that "pure elemental tungsten" generally includes commercially pure elemental tungsten, which can have a purity less than 100%. For example, in embodiments, the pure elemental tungsten can be of a grade having a purity of at least about 75%, or more preferably about 80%, or more preferably about 90%, or even more preferably about 99.95%. Further, pure elemental tungsten generally has a high modulus. For example, in embodiments, the Young's modulus of pure elemental tungsten can be at least about 400 gigapascals (GPa) when compared to other elements. Further, in embodiments, the shear modulus of pure elemental tungsten can be at least about 150 GPa. Thus, the high modulus provides hardness and damping to the protective cover 110 (particularly against shock waves generated due to droplet impact). More specifically, during water droplet impact, repeated shock waves are generated within the blade material, which over time leads to fatigue-related material failure. Pure elemental tungsten, by virtue of its high modulus and hardness, can absorb the acoustic shock waves, thus ensuring that material deformation remains elastic. This is able to delay the onset of damage and helps to keep the blade aerodynamic surface for a longer duration.

[0048] Pure elemental tungsten is also very resistant to erosion, such as those found in marine environments. For example, pure elemental tungsten is generally inert to the general chemical environment including oxygen at room temperature, and its reactivity increases with increasing temperature. Thus, in marine environments (which are generally acidic), pure elemental tungsten can be more resistant to erosion than other alkaline media. Further, the high resistance to erosion is maintained in the use of pure elemental tungsten without any other elements, as the resistance to erosion is reduced in the presence of a binder phase, including attack of intergranular boundaries to different phases.

[0049] This combination of corrosion and erosion resistance is unique. In another aspect, cermet materials, such as tungsten carbide (in sintered or coated form), are prone to droplet corrosion and / or erosion damage due to the presence of carbide binder interfaces that become sites for corrosion and / or erosion damage.

[0050] Further, the tungsten-based metal can be formed into any suitable shape having any suitable thickness. For example, in an embodiment, the tungsten-based metal described herein can be formed into one or more foil sheets of material. In another embodiment, the tungsten-based metal can be formed into one or more strips. In yet another embodiment, the tungsten-based metal can be formed into one or more plates or one or more sheets.

[0051] In another embodiment, the second segment(s) 116, where applicable, can be composed of a different material such as a polymeric material, a nickel alloy such as, by way of example, nickel-chromium or nickel-chromium-molybdenum, an aluminum alloy, a titanium alloy, a steel alloy, or any other suitable material.

[0052] In particular embodiments, the protective cover 110 can be secured to the rotor blade surface(s) using any suitable means, such as via an adhesive, a mechanical joint, or one or more fasteners, and / or combinations thereof. Further, as shown in Figures 3 to 6 the protective cover 110 can have an over-clamp spring configuration that clamps onto the rotor blade surface(s) such as around the leading edge 26, or in the absence of a leading edge, the pressure side surface 22 and the suction side surface 24. Among other things, as generally shown in Figures 4 to 6 the protective cover 110 includes a main body 112 that defines an overall length L. Further, in some embodiments, the thickness T of the protective cover 110 can taper or vary generally throughout a portion of the protective cover 110, such as along at least a portion of the overall length L of the protective cover 110. For example, as shown in Figures 4 to 6 the thickness T of the main body 112 of the protective cover 110 is greater at a middle of the protective cover 110, as shown at T2, than at the edges, as shown at Tl.

[0053] In further embodiments, the over-clamp spring configuration can also include at least one of an inner thickened edge or an outer thickened edge. For example, as shown in Figure 5 the over-clamp spring configuration of the protective cover 110 can include an outer thickened edge 118. Alternatively, as shown in Figure 6 the over-clamp spring configuration of the protective cover 110 includes an inner thickened edge 120. Such edges can be provided onto the main body 112 of the protective cover 110, for example, via any suitable method, such as by additive manufacturing the edges 118, 120 onto the main body 112, bonding the edges 118, 120 onto the main body 112, fastening the edges 118, 120 onto the main body 112, or the like. Thus, in such embodiments, the thickened edges 118, 120 are configured to avoid end cracking in the protective cover 110.

[0054] In alternative embodiments, as shown in Figures 7 to 9As shown, the protective cover 110 may have an internal clamping configuration that is at least partially fixed within the inner cavity 122 of the rotor blade 16. In such embodiments, the internal clamping configuration may include a protruding leading edge portion 124 and opposing flanges 126, 128. More specifically, in embodiments, as shown in Figure 7 and Figure 9 As shown, opposing flanges 126, 128 may, for example, be secured within the inner cavity 122 of the rotor blade 16 to one or more inner surfaces 130 of the rotor blade 16. In such embodiments, the inner clamping configuration of the protective cover 110 may also be spring-like, such that opposing flanges 126, 128 may be biased toward each other for inserting the protective cover 110 into the opening 132 defined by the pressure-side surface 22 and the suction-side surface 24. Figure 9 Therefore, once it is in Figure 7 As shown in the figure, it is inserted, with the leading edge portion 124 defining the leading edge 26 of the rotor blade 16.

[0055] In addition, the leading edge portion 124 and the opposing flanges 126, 128 may be formed of one or more suitable materials. In one embodiment, the leading edge portion 124 and the opposing flanges 126, 128 may be formed of the same material. Alternatively, in another embodiment, the leading edge portion 124 may be formed of a first material, and the opposing flanges 126, 128 may be formed of a second material, wherein the first material and the second material are different. In such embodiments, an electroforming process may be used to form the protective cap 110 of different materials.

[0056] Return to reference Figure 2 The protective cover 110 can be integrated with the lightning protection system 134 of the rotor blades 16. More specifically, as shown, the lightning protection system 134 may include at least one receiver 136, which may be electrically connected to the protective cover 110, for example, via one or more lightning protection devices 138, and may be electrically connected to the ground to reduce lightning damage to the rotor blades 16. For example, the lightning receiver(s) 136 may include a material suitable for guiding current from a lightning strike to the ground. In an exemplary embodiment, the lightning receiver(s) 136 may be formed of metal or metal alloy. For example, the lightning receiver(s) 136 may be formed of aluminum. However, alternatively, the lightning receiver(s) 136 may be formed of any suitable conductive material. Thus, the lightning receiver(s) 136 may correspond to bolts or rivets. Furthermore, in embodiments, the lightning protection devices 138 may be cables, such as copper cables.

[0057] Accordingly, the protective cover 110 can be fastened or otherwise secured to the rotor blade 16 by the lightning receptor(s) 136 (e.g., via one or more rivets). Thus, as shown in Figure 11 the protective cover 110 can include one or more through-holes 145 for receiving the lightning receptor(s) 136. The aspect of fastening the protective cover 110 (which can then be bolted to the rotor blade 16) by making through-holes (such as fish-eyes) in the protective cover 110 provides lightning protection to the protective cover 110 and also secures the protective cover 110 in the event of a disbonding incident from the rotor blade 16 during service. It should be appreciated that any suitable number of rivet locations can also be provided to fasten the protective cover 110 to the rotor blade 16.

[0058] Still referring to Figure 2 As shown, the lightning protection device(s) 138 can be disposed at least partially in the interior of the rotor blade 16, for example, within the interior cavity 122 of the rotor blade 16. For example, the lightning protection device(s) 138 can extend through at least a portion of the length of the rotor blade 16 in the interior. Further, in some embodiments, the lightning protection device(s) 138 can be connected at various locations along the length of the rotor blade 16 to one or more of the lightning receptors 136 disposed on one or more of the surfaces of the rotor blade 16. It should be appreciated that the protective cover 110 can replace or supplement some of the lightning receptors. The lightning protection device 138 can also be in conductive communication with a grounding system (not shown) in the wind turbine 10, such as in the tower 12 of the wind turbine 10.

[0059] Referring now to Figure 10 FIG. 1 1 illustrates a flowchart of one embodiment of a method 200 for manufacturing a rotor blade assembly for a wind turbine, such as the rotor blade assembly 100. Generally, the method 200 is described herein as being performed for manufacturing the rotor blade assembly 100 described above. However, it should be appreciated that the disclosed method 200 can be used to manufacture any other rotor blade assembly and / or protective cover. In addition, although the steps are depicted in a particular order for purposes of illustration and discussion, Figure 10 depicted in a particular order, the methods described herein are not limited to any particular order or arrangement. One of skill in the art, using the disclosures provided herein, will appreciate that various steps of the methods can be omitted, rearranged, combined, and / or modified in various ways.

[0060] As shown at (202), the method 200 includes providing a rotor blade having a surface defining a pressure side, a suction side, a leading edge, and a trailing edge extending between a blade tip and a blade root. As shown at (204), the method 200 includes forming a protective cover 110 having a shape corresponding to a curvature of one or more of the surfaces of the rotor blade 16. More particularly, in embodiments, the protective cover 110 can be formed via sheet press forming, laser sheet forming, additive manufacturing, electroforming, cold spraying, rolling, case hardening, coating deposition, sintering, or similar methods, and combinations thereof.

[0061] Further, as mentioned, the protective cover 110 can be formed from multiple segments. More particularly, in such embodiments, a first segment 114 of the protective cover 110 can be formed from a tungsten-based metal, while a second segment 116 of the protective cover 110 can be formed from a different material. In particular embodiments, the tungsten-based metal can include, for example, pure elemental tungsten, tungsten titanium, tungsten silicon, tungsten nickel, or tungsten aluminum, while the different material can include a polymeric material, a shape memory alloy, a nickel alloy (such as, for example, nickel-chromium or nickel-chromium-molybdenum), an aluminum alloy, a titanium alloy, a steel, or any other suitable material.

[0062] Still referring to Figure 10 As shown at (206), the method 200 includes arranging the protective cover 110 adjacent to one or more of the surfaces of the rotor blade 16 so as to cover or form at least a portion of one or more surfaces of the rotor blade 16. As shown at (208), the method 200 includes securing the protective cover 110 to one or more of the surfaces of the rotor blade 16 such that the first segment 114 of the protective cover 110 (which is formed from the tungsten-based metal) is arranged adjacent to the blade tip 32. Thus, the protective cover 110 is configured to reduce corrosion of the rotor blade 16 caused by particle or liquid impact and to resist erosion of the rotor blade 16 caused thereby.

[0063] For example, in embodiments, the protective cover 110 can be secured to one or more of the rotor blade surfaces via at least one of an adhesive, a mechanical joint, or any other suitable securing method. For example, in embodiments, as mentioned, the mechanical joint can include an over-clamp spring configuration (e.g., external to one or more of the rotor blade surfaces) or an under-clamp configuration (e.g., internal to one or more of the rotor blade surfaces).

[0064] Thus, where the mechanical joint is an over-clamp configuration, the method 200 can include varying a thickness of a cross-section of the over-clamp spring configuration along at least a portion of an overall length of the protective cover 110, for example, via additive manufacturing, electroforming, cold spraying, or combinations thereof. Alternatively, the thickness of the cross-section of the over-clamp spring configuration can be constant along the overall length of the protective cover 110.

[0065] In further embodiments, as generally shown in, for example, Figures 5 to 6 and Figures 11 to 13 the method 200 can further include forming at least one additional feature onto the protective cover 110 via at least one of additive manufacturing, electroforming, cold spraying, rolling, surface hardening, or similar methods, and combinations thereof. In such embodiments, the additional feature(s) can include an internal thickened edge 124, an external thickened edge 122, one or more flanges 126, 128, an aerodynamic surface feature 144, or any other suitable feature. For example, as shown in Figure 11 and Figure 12 the protective cover 110 is formed with a plurality of vortex generators 146 thereon. In another embodiment, as shown in Figure 13 the protective cover 110 can be formed or otherwise attached to an additively manufactured metal mesh reinforced winglet 148. In such embodiments, the protective cover 110 can be secured to the blade tip 32 of the rotor blade 16 so as to alter one or more aerodynamic properties of the tip 32. In yet another embodiment, as shown in Figure 4 the protective cover 110 can further include a tip portion 150 that is formed or otherwise secured to the blade tip 32 of the rotor blade 16 so as to alter one or more aerodynamic properties of the tip 32.

[0066] In yet another further embodiment, as mentioned with reference to Figure 2 the method 200 can include integrating the protective cover 110 with the lightning protection system 134 of the rotor blade 16, for example via rivets or bolts, and using the methods described herein.

[0067] Various aspects and embodiments of the present invention are defined by the following numbered clauses:

[0068] Clause 1. A rotor blade assembly, comprising:

[0069] at least one rotor blade having a surface defining a pressure side, a suction side, a leading edge, and a trailing edge extending between a blade tip and a blade root, the surface composed of a polymer composite; and

[0070] a protective cover disposed proximate to one or more of the surfaces of the rotor blade so as to cover at least a portion of the one or more surfaces of the rotor blade, the protective cover including a main body defining an overall length, at least a first section of the protective cover composed of a tungsten-based metal,

[0071] wherein the protective cover is configured to reduce corrosion of the rotor blade caused by particle or liquid impact and to resist erosion of the rotor blade caused thereby.

[0072] Clause 2. The rotor blade assembly of Clause 1, wherein the protective cover covers at least a portion of the leading edge of the rotor blade.

[0073] Clause 3. The rotor blade assembly of any preceding claim, wherein the tungsten-based metal comprises at least one of elemental tungsten, tungsten titanium, tungsten silicon, tungsten nickel, or tungsten aluminum.

[0074] Clause 4. The rotor blade assembly of any preceding claim, wherein the tungsten-based metal is formed into at least one of a foil, one or more strips, one or more plates, or one or more sheets.

[0075] Clause 5. The rotor blade assembly of any preceding claim, wherein the protective cover is secured to the one or more of the surfaces via an adhesive.

[0076] Clause 6. The rotor blade assembly of any preceding claim, wherein the protective cover comprises an overclip spring configuration clipped onto the one or more of the surfaces of the rotor blade.

[0077] Clause 7. The rotor blade assembly of Clause 6, wherein a thickness of a cross-section of the overclip spring configuration varies along at least a portion of the overall length of the protective cover.

[0078] Clause 8. The rotor blade assembly of Clause 7, wherein the overclip spring configuration further comprises at least one of an inner thickened edge or an outer thickened edge.

[0079] Clause 9. The rotor blade assembly of any preceding claim, wherein the protective cover comprises an innerclip configuration at least partially secured within an inner cavity of the rotor blade.

[0080] Clause 10. The rotor blade assembly of Clause 9, wherein the innerclip configuration comprises a protruding leading edge portion and an opposing flange secured to an inner surface of the one or more of the surfaces of the rotor blade within the inner cavity of the rotor blade.

[0081] Clause 11. The rotor blade assembly of any preceding claim, wherein at least a second segment of the protective cover is composed of a polymeric material.

[0082] Clause 12. The rotor blade assembly of any preceding claim, wherein the protective cover is integrated with a lightning protection system of the rotor blade.

[0083] Clause 13. A method for manufacturing a rotor blade assembly, the method comprising:

[0084] providing at least one rotor blade having a surface defining a pressure side, a suction side, a leading edge, and a trailing edge extending between a blade tip and a blade root, the surface comprised of a polymer composite;

[0085] forming a protective cover having a shape corresponding to a curvature of one or more of the surfaces of the rotor blade, wherein a first section of the protective cover is formed of a tungsten-based metal and a second section of the protective cover is formed of a different material;

[0086] disposing the protective cover adjacent to one or more of the surfaces of the rotor blade so as to cover at least a portion of the one or more surfaces of the rotor blade; and,

[0087] securing the protective cover to the one or more of the surfaces of the rotor blade such that the first section of the protective cover formed of the tungsten-based metal is disposed adjacent to the blade tip, the protective cover configured to reduce corrosion of the rotor blade caused by particle or liquid impact and to resist erosion of the rotor blade caused thereby.

[0088] Clause 14. The method of clause 13, wherein forming the protective cover further comprises at least one of sheet press forming, laser sheet forming, additive manufacturing, electroforming, cold spraying, rolling, case hardening, coating deposition, sintering, or a combination thereof.

[0089] Clause 15. The method of clauses 13-14, wherein the tungsten-based metal comprises at least one of elemental tungsten, tungsten titanium, tungsten silicon, tungsten nickel, or tungsten aluminum, and the different material comprises at least one of a polymeric material, a shape memory alloy, a nickel alloy, an aluminum alloy, a titanium alloy, or a steel alloy.

[0090] Clause 16. The method of clauses 13-15, wherein securing the protective cover to the one or more of the surfaces of the rotor blade further comprises securing the protective cover to the one or more of the surfaces of the rotor blade via at least one of an adhesive or a mechanical joint, the mechanical joint comprising at least one of an over-clip spring configuration, an under-clip configuration, or one or more fasteners.

[0091] 17. The method of clause 16, further comprising forming a thickness of a cross-section of the over-clip spring configuration to vary along at least a portion of the overall length of the protective cover via at least one of additive manufacturing, electroforming, cold spraying, or a combination thereof.

[0092] Clause 18. The method of clause 16, further comprising forming at least one additional feature onto the protective cover via at least one of additive manufacturing, electroforming, cold spraying, or a combination thereof, the at least one additional feature comprising at least one of an internal thickened edge, an external thickened edge, one or more flanges, or an aerodynamic surface feature.

[0093] Clause 19. The method of clause 16, wherein the inner-clip configuration comprises a protruding leading edge portion and an opposing flange, the method further comprising:

[0094] forming the leading edge portion from a first material and the opposing flange from a second material, the first material and the second material being different;

[0095] securing the opposing flange to an inner surface of the one or more of the surfaces of the rotor blade within an inner cavity of the rotor blade.

[0096] Clause 20. A protective cover for disposition adjacent to one or more surfaces of a rotor blade so as to cover at least a portion of the one or more surfaces of the rotor blade, the protective cover comprising:

[0097] a body defining an overall length,

[0098] wherein at least a first section of the protective cover is composed of a single elemental tungsten, and

[0099] wherein the protective cover is configured to reduce corrosion of the rotor blade caused by particle or liquid impact and to resist erosion of the rotor blade caused thereby.

[0100] This written description uses examples to disclose the application, including the best mode, and also to enable any person skilled in the art to practice the application, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the application is defined by the claims, and can 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 rotor blade assembly comprising: at least one rotor blade having a surface defining a pressure side, a suction side, a leading edge, and a trailing edge extending between a blade tip and a blade root, the surface comprised of a polymer composite material; and a protective cover having a shape corresponding to a curvature of one or more of the surfaces of the rotor blade and disposed adjacent to one or more of the surfaces of the rotor blade so as to cover at least a portion of the one or more surfaces of the rotor blade, the protective cover comprising a main body defining an overall length, at least a first section of the protective cover comprised of a tungsten-based metal and disposed adjacent to the blade tip, and at least a second section of the protective cover comprised of a polymeric material, wherein the protective cover is configured to reduce corrosion and resist erosion of the rotor blade caused by particle or liquid impact, wherein the protective cover comprises an inner clip configuration at least partially secured within an internal cavity of the rotor blade.

2. The rotor blade assembly of claim 1, wherein, The protective cover covers at least a portion of the leading edge of the rotor blade.

3. The rotor blade assembly of claim 1, wherein, The tungsten-based metal comprises at least one of elemental tungsten, tungsten titanium, tungsten silicon, tungsten nickel, or tungsten aluminum.

4. The rotor blade assembly of claim 1, wherein, The tungsten-based metal is formed into at least one of a foil, one or more strips, one or more plates, or one or more sheets.

5. The rotor blade assembly of claim 1, wherein, The protective cover is secured to the one or more of the surfaces via an adhesive.

6. The rotor blade assembly of claim 1, wherein, The inner clip configuration comprises a protruding leading edge portion and opposing flanges secured to an inner surface of the one or more of the surfaces of the rotor blade within the internal cavity of the rotor blade.

7. The rotor blade assembly of claim 1, wherein, The protective cover is integrated with a lightning protection system of the rotor blade.

8. A method for manufacturing a rotor blade assembly, the method comprising: providing at least one rotor blade having a surface defining a pressure side, a suction side, a leading edge, and a trailing edge extending between a blade tip and a blade root, the surface comprised of a polymer composite material; forming a protective cover having a shape corresponding to a curvature of one or more of the surfaces of the rotor blade, wherein a first section of the protective cover is formed of a tungsten-based metal, and a second section of the protective cover is formed of a polymeric material; disposing the protective cover adjacent to one or more of the surfaces of the rotor blade so as to cover at least a portion of the one or more surfaces of the rotor blade; and securing the protective cover to the one or more of the surfaces of the rotor blade such that the first section of the protective cover formed of the tungsten-based metal is disposed adjacent to the blade tip, the protective cover configured to reduce corrosion and resist erosion of the rotor blade caused by particle or liquid impact, wherein securing the protective cover to the one or more of the surfaces of the rotor blade further comprises securing the protective cover to the one or more of the surfaces of the rotor blade via an inner clip configuration.

9. The method of claim 8, wherein, Forming the protective cover further comprises at least one of sheet press forming, laser sheet forming, additive manufacturing, electroforming, cold spraying, rolling, case hardening, coating deposition, sintering, or a combination thereof.

10. The method of claim 8, wherein, The tungsten-based metal comprises at least one of elemental tungsten, tungsten titanium, tungsten silicon, tungsten nickel, or tungsten aluminum, the different material comprises at least one of a polymeric material, a shape memory alloy, a nickel alloy, an aluminum alloy, a titanium alloy, or a steel alloy.

11. The method of claim 8, wherein, Securing the protective cover to the one or more of the surfaces of the rotor blade further comprises securing the protective cover to the one or more of the surfaces of the rotor blade via at least one of an adhesive or one or more fasteners.

12. The method of claim 11, further comprising: Forming at least one additional feature on the protective cover via at least one of additive manufacturing, electroforming, cold spraying, or a combination thereof, the at least one additional feature comprising at least one of an internal thickened edge, an external thickened edge, one or more flanges, or an aerodynamic surface feature.

13. The method of claim 11, wherein, The inner clip configuration comprises a protruding leading edge portion and an opposing flange, the method further comprising: forming the leading edge portion from a first material and the opposing flange from a second material, the first material and the second material being different; securing the opposing flange to an inner surface of the one or more of the surfaces of the rotor blade within an inner cavity of the rotor blade.

14. A protective cover having a shape corresponding to a curvature of one or more of surfaces of a rotor blade and for disposition adjacent to one or more surfaces of a rotor blade so as to cover at least a portion of the one or more surfaces of the rotor blade, the protective cover comprising: a body defining an overall length, wherein at least a first section of the protective cover is comprised of elemental tungsten and is disposed adjacent to the blade tip and at least a second section of the protective cover is comprised of a polymeric material, and wherein the protective cover is configured to reduce corrosion and resist erosion of the rotor blade caused by particle or liquid impact, wherein the protective cover comprises an inner clip configuration at least partially secured within an inner cavity of the rotor blade.

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