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EP-4737707-A1 - SERRATED PANEL FOR A WIND TURBINE ROTOR BLADE

EP4737707A1EP 4737707 A1EP4737707 A1EP 4737707A1EP-4737707-A1

Abstract

A serrated panel for a trailing edge of a wind turbine rotor blade, the serrated panel comprising • a plurality of teeth, each tooth having a tip, a base, two edges running from the tip to the base, a pressure side surface and a suction side surface, and • a plurality of vanes arranged side by side with a gap between each pair of adj acent vanes, each vane beginning at one of said edges and extending rearwards in a longitudinal direction, wherein each vane has a vane length, a vane width and a vane height, characterized in that • the pressure side surfaces of the teeth comprise a base surface and a plurality of humps, wherein each hump has a crest and a sloped, circumferential surface that transitions smoothly into the base surface.

Inventors

  • LIPKA, THOMAS
  • Rautmann, Christof
  • Dibbern, Adrian

Assignees

  • Nordex Energy SE & Co. KG

Dates

Publication Date
20260506
Application Date
20241030

Claims (15)

  1. A serrated panel (10) for a trailing edge (8) of a wind turbine rotor blade (1), the serrated panel (10) comprising • a plurality of teeth (14), each tooth (14) having a tip (24), a base (26), two edges (28) running from the tip (24) to the base (26), a pressure side surface (32) and a suction side surface (34), and • a plurality of vanes (42) arranged side by side with a gap between each pair of adjacent vanes (42), each vane (42) beginning at one of said edges (28) and extending rearwards in a longitudinal direction, wherein each vane (42) has a vane length (48), a vane width (74) and a vane height (72), characterized in that • the pressure side surfaces (32) and/or suction side surfaces (34) of the teeth (14) comprise a base surface (52) and a plurality of humps (44), wherein each hump (44) has a crest (64) and a sloped, circumferential surface (66) that transitions smoothly into the base surface (52).
  2. The serrated panel (10) of claim 1, wherein the crests (64) are rounded.
  3. The serrated panel (10) of claim 1 or 2, wherein in a section in a first plane parallel to the base surface (52), the humps (44) are circular or elliptical.
  4. The serrated panel (10) of any of the claims 1 to 3, wherein the humps (44) are arranged along straight lines (56) which are aligned with or parallel to the longitudinal direction of the vanes (42).
  5. The serrated panel (10) of claim 4, wherein the humps (44) along the straight lines (56) are arranged directly adjacent to one another.
  6. The serrated panel (10) of claim 4 or 5, wherein a distance (62) between neighboring straight lines (56) corresponds to a hump width (60).
  7. The serrated panel (10) of any of the claims 4 to 6, wherein every other one of the vanes (42) is aligned with one of the straight lines (56).
  8. The serrated panel (10) of any of the claims 4 to 7, wherein the humps (44) arranged along one of the straight lines (56) are offset in the longitudinal direction from the humps (44) arranged in a neighboring one of the straight lines (56).
  9. The serrated panel (10) of claims 8, wherein the offset in the longitudinal direction is in a range of 40 % to 60 % of a hump length (58).
  10. The serrated panel (10) of any of the claims 1 to 9, wherein the humps (44) have a hump width (60) in a range of 1 to 2 times of the vane (42) width.
  11. The serrated panel (10) of any of the claims 1 to 10, wherein the humps (44) have a hump length (58) which is in a range of 1 to 5 times of the vane width (74).
  12. The serrated panel (10) of any of the claims 1 to 11, wherein the humps (44) have a hump height (70) which is in a range of 50 % to 90 % of the vane height (72).
  13. The serrated panel (10) of any of the claims 1 to 12, wherein the pressure side surfaces (32) along the edges (28) comprise a border section in which no humps (44) are arranged.
  14. The serrated panel (10) of claim 13, wherein a plurality of transition elements (50) are arranged in the border section, wherein each transition element (50) is arranged forward of one of the vanes (42) and has an outer surface forming a smooth transition between the vane (42) and the base surface (52) of the pressure side surface (32), in particular wherein a transition element width (78) is larger than the vane width (74).
  15. The serrated panel (10) of any of the claims 1 to 14, wherein the serrated panel (10) comprises an attachment section (12) having a leading edge (16), an attachment surface (20) for connecting the serrated panel (10) to a trailing edge of a wind turbine rotor blade, a rear end (18), and an external surface (22) opposite the attachment surface (20), wherein the bases (26) of the teeth (14) are arranged at the rear end (18).

Description

The invention relates to a serrated panel for the trailing edge of a wind turbine rotor blade. These panels have been suggested for noise reduction in wind turbines. The panels are designed with a series of teeth placed along the trailing edge of the wind turbine rotor blade, which can help reducing aerodynamic noise generated by the rotor blade. In particular, the serrations on the trailing edge of a wind turbine rotor blade change the local flow behavior at the trailing edge and the interaction of turbulent vortices with the trailing edge, thereby reducing the overall noise level produced by the wind turbine. Studies have shown that the use of serrated panels can reduce the noise level of wind turbines significantly. This can help to make wind turbines more acceptable to local communities by reducing the impact of noise pollution. WO 2022/135751 A1 shows a trailing edge panel for a wind turbine rotor blade. It comprises a base element and serrations extending from a rear end of the base element. On one side of the serrations, rib-shaped protruding elements are arranged along a longitudinal direction of the serrations. The protruding elements extend in a direction towards a leading edge of the wind turbine rotor blade beyond the rear end of the base element. The protruding elements may be shaped as a finlet or as a three-dimensional, cone-shaped structure. WO 2022/205817 A1 shows a serrated panel having a base part and a plurality of serrations. The serrations are provided with secondary teeth. In an embodiment, one side of the serrated panel is provided with ribs ending on the secondary teeth. EP 3 164 599 B1 shows a serrated panel having serrations and U-shaped vanes arranged along a longitudinal direction of the serrations. EP 3 348 826 B1 shows a serrated panel having serrations and vanes arranged on both sides of the serrations along a longitudinal direction of the serrations. On one side of the panel, the vanes extend over an outer surface of an attachment section. EP 2 851 555 B1 shows a wind turbine rotor blade with a trailing edge provided with a number of serrations. One side of the serrations is provided with vanes. EP 2 867 523 B1 shows a serrated panel for a wind turbine rotor blade having serrations provided with stiffening ribs. WO 2020/224737 A1 shows a wind turbine rotor blade provided with serrations projecting from a trailing edge and distinct fins projecting from a surface of the blade arranged upstream of the serrations. From the document EP 3 268 605 B1, a wind turbine rotor blade with a serrated panel having the features of the preamble of claim 1 has become known. Parts of the serrated panel are provided with ridges or fins. Departing therefrom, it is an object of the invention to provide a serrated panel offering improved noise reduction. This problem is solved by the serrated panel with the features of claim 1. Preferred aspects are given in the dependent claims. The serrated panel is designed for a trailing edge of a wind turbine rotor blade and comprises: a plurality of teeth, each tooth having a tip, a base, two edges running from the tip to the base, a pressure side surface and a suction side surface, anda plurality of vanes arranged side by side with a gap between each pair of adj acent vanes, each vane beginning at one of said edges and extending rearwards in a longitudinal direction, wherein each vane has a vane length, a vane width and a vane height, whereinthe pressure side surfaces and/or suction side surfaces of the teeth comprise a base surface and a plurality of humps, wherein each hump has a crest and a sloped, circumferential surface that transitions smoothly into the base surface. The serrated panel is designed for being integrated into or attached to a wind turbine rotor blade at a trailing edge of the wind turbine rotor blade. When the serrated panel is mounted to the wind turbine rotor blade, the teeth extend beyond the wind turbine rotor blade's trailing edge. In particular, the teeth may be arranged such that the bases of the teeth are substantially aligned with the trailing edge of the wind turbine rotor blade. Each tooth has a tip and two edges running from the tip to one end of the base. The edges may be straight, giving the tooth a triangular shape. However, the edges may also include some curvature. The teeth are arranged side-by-side. The base may be formed by an imaginary, straight line which connects two forward ends of recesses formed between adjacent teeth. A longitudinal axis of a tooth extends from the base to the tip, and generally describes a longitudinal direction of the tooth. The longitudinal axis may in particular extend through a midpoint of the base. The point where the longitudinal axis bisects the base may also be shifted towards one side, for example when the tooth has an asymmetrical shape. The geometry of all the teeth may be the same, so that all teeth have the same width, length and shape. However, this is not required. Each tooth ha