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EP-4737706-A1 - SERRATED PANEL FOR A WIND TURBINE ROTOR BLADE

EP4737706A1EP 4737706 A1EP4737706 A1EP 4737706A1EP-4737706-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 longitudinal axis, a pressure side surface and a suction side surface, and • a plurality of vanes arranged side by side with a gap between adjacent vanes, each vane beginning at one of said edges and extending in a rearward direction, wherein each vane has a vane length, a vane width and a vane height, characterized in that • the pressure side surfaces and/or the suction side surfaces of the teeth comprise wave elements beginning at or near one of the edges and extending in a forward direction, wherein each wave element has a crest which is aligned with one of the vanes and a wave element width which is larger than the vane width.

Inventors

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

Assignees

  • Nordex Energy SE & Co. KG

Dates

Publication Date
20260506
Application Date
20241030

Claims (14)

  1. A serrated panel (10) for a trailing edge of a wind turbine rotor blade, the serrated panel (10) comprising • a plurality of teeth (14), each tooth (14) having a tip (24), a base (25), two edges (28) running from the tip (24) to the base (26), a longitudinal axis (38), 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 adjacent vanes (42), each vane (42) beginning at one of said edges (28) and extending in a rearward direction, wherein each vane (42) has a vane length, a vane width (68) and a vane height (66), characterized in that • the pressure side surfaces (32) and/or the suction side surfaces (34) of the teeth (14) comprise wave elements (44) beginning at or near one of the edges (28) and extending in a forward direction, wherein each wave element (44) has a crest (52) which is aligned with one of the vanes (42) and a wave element width (64) which is larger than the vane width (68).
  2. The serrated panel (10) of claim 1, wherein the wave elements (44) in cross section have two sloped side surfaces (54) each having a first end arranged at the crest (52) of the respective wave element (44) and a second end arranged at a lowermost point between adjacent wave elements (44).
  3. The serrated panel (10) of claim 2, wherein the two sloped side surfaces (54) are curved and have a convex section (56) at or near the first end and/or a concave section (58) at or near the second end.
  4. The serrated panel (10) of claim 2, wherein a tangent to the sloped side surface (54) at the second end is arranged parallel to the suction side surface (34).
  5. The serrated panel (10) of any of the claims 1 to 4, wherein the wave elements (44) have a wave element height (62) which is smaller than the wave element width (64), in particular by a factor of 1.5 or more.
  6. The serrated panel (10) of claim 5, wherein the wave element height (62) decreases in the forward direction, in particular such that a distance between the crest (52) and the suction side surface (34) is constant.
  7. The serrated panel (10) of any of the claims 1 to 6, wherein the crests (52) of the wave elements (44) at a front end of the respective wave element transition smoothly into the pressure side surface (32) of the respective tooth (14).
  8. The serrated panel (10) of any of the claims 1 to 7, wherein the vanes (42) have a cross-section which is constant over their entire length or a largest part thereof.
  9. The serrated panel (10) of any of the claims 1 to 8, wherein the vanes (42) in cross-section have straight side surfaces arranged along the direction of the vane height (66).
  10. The serrated panel (66) of any of the claims 1 to 9, wherein the vane width (68) corresponds to a width of the gap between each pair of adjacent vanes (42).
  11. The serrated panel (10) of any of the claims 1 to 10, wherein the serrated panel (10) comprises a plurality of transition elements (70), wherein each transition element (70) is arranged between one of the vanes (42) and a wave element (44) aligned therewith, wherein an outer surface of the transition element (70) forms a smooth transition between the vane (42) and the wave element (44).
  12. The serrated panel (10) of claim 11, wherein each transition element (70) has a curved crest (72) with a front section smoothly transitioning in the crest (52) of the wave element (44) and a rear section smoothly transitioning in a crest (74) of the vane (42).
  13. The serrated panel (10) of any of the claims 1 to 12, 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).
  14. The serrated panel (10) of claim 13, wherein some of the wave elements (44) have a front end arranged on the external surface (22) of the attachment section (12).

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 to reduce 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 3 696 402 B1 shows a serrated panel having a plurality of spine members forming a number of serrations. First and second sections of the spine members have different stiffnesses. Third sections of the spine members form a mounting plate. 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. EP 2 921 697 B1 shows a wind turbine rotor blade with an airfoil having a modified trailing edge. The trailing edge has either serrations or a profile forming a zig-zap-pattern when seen from behind the airfoil. 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 B 1, 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 for a trailing edge of a wind turbine rotor blade comprises: a plurality of teeth, each tooth having a tip, a base, two edges running from the tip to the base, a longitudinal axis, a pressure side surface and a suction side surface, anda plurality of vanes arranged side by side with a gap between adj acent vanes, each vane beginning at one of said edges and extending in a rearward direction, wherein each vane has a vane length, a vane width and a vane height, whereinthe pressure side surfaces and/or the suction side surfaces of the teeth comprise wave elements beginning at or near one of the edges and extending in a forward direction, wherein each wave element has a crest which is aligned with one of the vanes and a wave element width which is larger than the vane width. 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 t