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EP-4735757-A1 - RESONATING STRUCTURE FOR WIND TURBINE BLADES

EP4735757A1EP 4735757 A1EP4735757 A1EP 4735757A1EP-4735757-A1

Abstract

A wind turbine blade (20) that extends longitudinally in a spanwise direction between a root end (24) and a tip end (26), and in a chordwise direction between a leading edge (28) and a trailing edge (30), is disclosed. The wind turbine blade (20) includes a first opposing half-shell portion (34) and a second opposing half-shell portion (36) which together define an interior (38) the wind turbine blade (20), and at least one shear web (52) that extends between the first opposing half-shell portion (34) and the second opposing half-shell portion (36). The wind turbine blade (20) further includes at least one vibration damping device (60, 90, 122, 124, 126, 128, 132, 204, 224, 230, 250) for reducing noise emission from the wind turbine blade (20). The at least one vibration damping device (60, 90, 122, 124, 126, 128, 132, 204, 224, 230, 250) includes at least one resonating member (62, 138, 202, 232, 260) that extends from a surface of the wind turbine blade (20) to a distal end (70, 96, 156, 186, 206, 234, 262) that is configured to oscillate to dissipate vibrational energy away from the surface of the wind turbine blade (20).

Inventors

  • SØE-KNUDSEN, Alf
  • GUPTA, Mranal

Assignees

  • VESTAS WIND SYSTEMS A/S

Dates

Publication Date
20260506
Application Date
20240626

Claims (20)

  1. 1 . A wind turbine blade (20) extending longitudinally in a spanwise direction between a root end (24) and a tip end (26), and extending in a chordwise direction between a leading edge (28) and a trailing edge (30), the wind turbine blade (20) comprising: a first opposing half-shell portion (34) and a second opposing half-shell portion (36) which together define an interior (38) of the wind turbine blade (20); at least one shear web (52) extending between the first opposing half-shell portion (34) and the second opposing half-shell portion (36); and at least one vibration damping device (60, 90, 122, 124, 126, 128, 132, 204, 224, 230, 250) for reducing noise emission from the wind turbine blade (20), the at least one vibration damping device (60, 90, 122, 124, 126, 128, 132, 204, 224, 230, 250) including at least one resonating member (62, 138, 202, 232, 260) that extends from a surface of the wind turbine blade (20) to a distal end (70, 96, 156, 186, 206, 234, 262) that is configured to oscillate to dissipate vibrational energy away from the surface of the wind turbine blade (20).
  2. 2. The wind turbine blade (20) of claim 1 , wherein the at least one vibration damping device (60, 90, 122, 124, 126, 128, 132, 204, 224, 230, 250) is located within the interior (38) of the wind turbine blade (20) such that the surface that the at least one resonating member (62, 138, 202, 232, 260) extends from is an interior surface of the wind turbine blade (20).
  3. 3. The wind turbine blade (20) of claim 2, wherein the interior surface is on the at least one shear web (52).
  4. 4. The wind turbine blade (20) of claim 2, wherein the interior surface is on the first opposing half-shell portion (34) or the second opposing half-shell (36).
  5. 5. The wind turbine blade (20) of any of the preceding claims, wherein the at least one resonating member (62) includes a core (78) and an outer skin (80).
  6. 6. The wind turbine blade (20) of claim 5, wherein the core (78) includes a resilient core material and a mass (84) positioned adjacent to the distal end (70) of the at least one resonating member (62).
  7. 7. The wind turbine blade (20) of any of claims 2-6, wherein the at least one vibration damping device (60, 90, 122, 124, 126, 128, 132, 204, 224, 230, 250) comprises at least a first vibration damping device (60, 90, 122, 124, 126, 128, 132, 204, 224, 230, 250) and a second vibration damping device (60, 90, 122, 124, 126, 128, 132, 204, 224, 230, 250) spaced apart and separately attached to the interior surface of the wind turbine blade (20).
  8. 8. The wind turbine blade of claim 7, wherein the first vibration damping device (60) and the second vibration damping device (60) extend in parallel.
  9. 9. The wind turbine blade (20) of any of claims 7 or 8, wherein the first vibration damping device (60, 90, 122, 124, 126, 128, 132, 204, 224, 230, 250) and the second vibration damping device (60, 90, 122, 124, 126, 128, 132, 204, 224, 230, 250) are configured to dissipate different bands of vibrational energy frequencies.
  10. 10. The wind turbine blade (20) of any of claims 2-9, wherein the at least one resonating member (62) is an elongate fin that extends a length along the surface of the wind turbine blade (20) in the spanwise direction.
  11. 11 . The wind turbine blade (20) of any of the preceding claims, wherein the at least one resonating member (62) includes a height measured between a first end attached to the interior surface of the wind turbine blade (20) and the distal end (70) and a thickness measured between a first side surface (72) and a second side surface (74), wherein the height is greater than the thickness.
  12. 12. The wind turbine blade (20) of claim 11 , wherein the first side surface (72) and the second side surface (74) of the at least one resonating member (62) are substantially planar.
  13. 13. The wind turbine blade (20) of any of the preceding claims, wherein the at least one resonating member (62) is wavy in transverse cross-section.
  14. 14. The wind turbine blade (20) of any of claims 11-13, wherein the height of the at least one resonating member (62) varies along a length of the at least one resonating member (62).
  15. 15. The wind turbine blade (20) of claim 1 , wherein the at least one vibration damping device (60, 90, 122, 124, 126, 128, 132, 204, 224, 230, 250) is located on an exterior of the wind turbine blade (20) such that the surface that the at least one resonating member (62, 138, 202, 232, 260) extends from is an exterior surface of the wind turbine blade (20).
  16. 16. The wind turbine blade (20) of claim 15, wherein the exterior surface is on the first opposing half-shell portion (34) or the second opposing half-shell portion (36).
  17. 17. The wind turbine blade (20) of any of the preceding claims, wherein the at least one damping device (60, 90, 122, 124, 126, 128, 132, 204, 224, 230, 250) is located at the root end (24) of the wind turbine blade (20).
  18. 18. The wind turbine blade (20) of any of the preceding claims, wherein the at least one resonating member (62, 138, 202, 232, 260) comprises a plurality of resonating members (62, 138, 202, 232, 260) connected together at a base (94, 212, 254) of the at least one damping device (60, 90).
  19. 19. The wind turbine blade (20) of claim 18, wherein the at least one vibration damping device (90, 122, 124, 126, 128, 132, 204, 224, 230, 250) extends circumferentially about the root end (24) of the wind turbine blade (20) to form an annular ring of resonating members (62, 138, 202, 232, 260).
  20. 20. The wind turbine blade (20) of any of claims 18 or 19, wherein the plurality of resonating members (62, 138, 232) are bridged together at each distal end (70, 156,

Description

RESONATING STRUCTURE FOR WIND TURBINE BLADES Technical Field This application relates generally to wind turbines, and more particularly to a system and method for damping vibrations of wind turbine blades to reduce the acoustic noise generated by wind turbine blades during operation of a wind turbine. Background Wind turbines are used to produce electrical energy using a renewable resource and without combusting a fossil fuel. Generally, a wind turbine converts kinetic energy from the wind into electrical power. A horizontal-axis wind turbine includes a tower, a nacelle located at the apex of the tower, and a rotor having a plurality of blades and supported in the nacelle by means of a shaft. The shaft couples the rotor either directly or indirectly with a generator, which is housed inside the nacelle. Consequently, as wind forces the blades to rotate the rotor, electrical energy is produced by the generator. To this end, wind turbines may be located either on a land mass (onshore) or within a body of water (offshore). As the demand for renewable energy sources has increased in recent years, the number of wind turbines installed worldwide has also grown significantly. Moreover, wind turbines have been developed in larger sizes to generate more electricity to meet the ever-growing demand for electrical energy. However, as wind turbines become more prevalent, one of the challenges associated with wind turbines is the generation of acoustic noise during their operation, which can cause disturbances for nearby residents. The blades are one component of the wind turbine that can generate acoustic noise during operation. Wind turbine blades, while designed to be aerodynamical ly efficient, can experience various forms of vibration during operation. These vibrations can be caused by factors such as turbulence, unsteady wind conditions, and mechanical interactions within the wind turbine structure. For example, during the operation of the wind turbine, vibrations can be generated by mechanical equipment within the nacelle, such as the gearbox, generator, and other equipment necessary for power generation. These vibrations can propagate from the nacelle and through the structure of the blades, contributing to the overall vibrational energy traveling along the length of the blades. As the vibrational energy travels along the length of the blade, it radiates into the surrounding air as sound waves, resulting in noise emissions. Conventional approaches to mitigate the acoustic noise generated by wind turbine blades include reducing the overall aerodynamic noise of the turbine blade. These approaches may include modifying the blade design, optimizing the rotational speed, or applying noise-reducing coatings. Other approaches include targeting the source of the vibrational energy traveling through the blade, such as by utilizing vibration mounts with the mechanical equipment within the nacelle, for example. While these approaches have demonstrated certain effectiveness, there is still a need to specifically address the issue of vibrational energy traveling along wind turbine blades and subsequently radiating as acoustic noise. Summary According to a first aspect of the invention, a wind turbine blade that extends longitudinally in a spanwise direction between a root end and a tip end, and extends in a chordwise direction between a leading edge and a trailing edge is disclosed. The wind turbine blade includes a first opposing half-shell portion and a second opposing half-shell portion which together define an interior of the wind turbine blade, and at least one shear web that extends between the first opposing half-shell portion and the second opposing half-shell. The wind turbine blade further includes at least one vibration damping device to reduce the noise emission from the wind turbine blade. In that regard, the at least one vibration damping device includes at least one resonating member that extends from a surface of the wind turbine blade to a distal end that is configured to oscillate to dissipate vibrational energy away from the surface of the wind turbine blade. A wind turbine including the wind turbine blade is also disclosed. The at least one resonating member extends from the surface of the wind turbine blade to a distal end of the resonating member. According to one embodiment of the invention, the at least one vibration damping device may be located within the interior of the wind turbine blade such that the surface that the at least one vibration damping device extends from may be an interior surface of the wind turbine blade. For example, the interior surface may be on the at least one shear web. Alternatively, the interior surface may be on the first opposing half-shell portion or the second opposing half-shell. According to another embodiment of the invention, the at least one resonating member may include a core and an outer skin. For instance, the core may include a resilient core material and a