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EP-4737705-A1 - SERRATED PANEL FOR A WIND TURBINE ROTOR BLADE

EP4737705A1EP 4737705 A1EP4737705 A1EP 4737705A1EP-4737705-A1

Abstract

A serrated panel for a trailing edge of a wind turbine rotor blade, the serrated panel comprising: • an attachment section having a leading edge, an attachment surface for connecting the serrated panel to a trailing edge of a wind turbine rotor blade, a rear end, and an external surface opposite the attachment surface, • a plurality of teeth, each tooth having a tip, a base which is arranged at the rear end of the attachment section, a longitudinal axis extending from the base to the tip, a pressure side surface, and a suction side surface, • wherein the external surface of the attachment section for each tooth has a transition surface forming a transition between the leading edge and the pressure side surface of the tooth, characterized in that • in a longitudinal section in a first plane that is perpendicular to the attachment surface and extends along the longitudinal axis of the tooth, the transition surface has a forward, concave section and a rearward, convex section, wherein the forward, concave section is arranged nearer to the leading edge of the attachment section than the rearward, convex section.

Inventors

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

Assignees

  • Nordex Energy SE & Co. KG

Dates

Publication Date
20260506
Application Date
20241030

Claims (13)

  1. A serrated panel (10) for a trailing edge (52) of a wind turbine rotor blade (50), the serrated panel (10) comprising: • an attachment section (12) having a leading edge (16), an attachment surface (20) for connecting the serrated panel (10) to a trailing edge (52) of a wind turbine rotor blade (50), a rear end (18), and an external surface (22) opposite the attachment surface (20), • a plurality of teeth (14), each tooth (14) having a tip (24), a base (26) which is arranged at the rear end (18) of the attachment section (12), a longitudinal axis (38) extending from the base (26) to the tip (24), a pressure side surface (32), and a suction side surface (34), • wherein the external surface (22) of the attachment section (12) for each tooth (14) has a transition surface (40) forming a transition between the leading edge (16) and the pressure side surface (32) of the tooth (14), characterized in that • in a longitudinal section in a first plane (42) that is perpendicular to the attachment surface (20) and extends along the longitudinal axis (38) of the tooth (14), the transition surface (40) has a forward, concave section (44) and a rearward, convex section (46), wherein the forward, concave section (44) is arranged nearer to the leading edge (16) of the attachment section (12) than the rearward, convex section (46).
  2. The serrated panel (10) of claim 1, wherein the pressure side surface (32) comprises two planar surfaces (36) meeting along a ridge (30) of the respective tooth (14), the ridge (30) extending between the tip (24) and an apex (48) near a midpoint of the base (26).
  3. The serrated panel (10) of claim 2, wherein the ridge (30) of the tooth (14) is arranged in the first plane (42).
  4. The serrated panel (10) of claim 2 or 3, wherein the transition surface (40) comprises a ridge (64) arranged in continuation of the ridge (30) of the tooth (14).
  5. The serrated panel (10) of any of the claims 1 to 4, wherein in a longitudinal section in a second plane (58) that is parallel to the first plane (42), the transition surface (40) has a forward, concave section (44) and a rearward, convex section (46).
  6. The serrated panel (10) of any of the claims 1 to 5, wherein the concave section (44) in the first plane (42) transitions smoothly into the convex section (46) in the first plane (42) and/or the concave section (44) in the second plane (58) transitions smoothly into the convex section (46) in the second plane (58).
  7. The serrated panel (10) of any of the claims 1 to 4, wherein the convex section (46) in the first plane (42) transitions smoothly into the ridge (30) of the tooth (14).
  8. The serrated panel (10) of any of the claims 5 to 7, wherein the convex section (46) in the second plane (58) transitions smoothly into the pressure side surface (32) of the tooth (14).
  9. The serrated panel (10) of any of the claims 1 to 8, wherein the serrated panel (10) has a reference line adapted to be positioned at the trailing edge (52) when the serrated panel (10) is mounted to the wind turbine rotor blade (50).
  10. The serrated panel (10) of any of the claims 1 to 9, wherein the longitudinal axis (38) of the tooth (14) is arranged at an angle to the reference line in the range of 60° to 88°.
  11. The serrated panel (10) of any of the claims 1 to 10, wherein in a cross section in a third plane (60) that is perpendicular to the attachment surface (20) and perpendicular to the first plane (42), the transition surface (40) comprises two concave sections (62) forming a ridge (64) of the transition surface (40).
  12. The serrated panel (10) of any of the claims 1 to 11, wherein in a cross section in a fourth plane (66) that is perpendicular to the attachment surface (20) and perpendicular to the first plane (42), the tooth (14) is triangular.
  13. The serrated panel (10) of any of the claims 1 to 12, wherein the tooth (14) comprises two straight side edges (28) running from the tip (24) to one end of the base (26).

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. EP 3 084 209 B1 shows a serrated panel for a wind turbine rotor blade having a base portion for attachment to a surface of a wind turbine rotor blade and a plurality of serrations projecting from the base portion. The base portion has a series of partial cutouts defining projecting elements. The projecting elements are linked to the serrations so that a bending movement of a serration will result in a corresponding movement of a projecting element which shall act as a deployable vortex generator. EP 2 867 523 B1 shows a serrated panel for a wind turbine rotor blade having serrations provided with stiffening ribs. WO 2014/044414 A1 shows a serrated panel for a wind turbine rotor blade having serrations arranged at an angle of 75° to 90° to a trailing edge of the wind turbine rotor blade. EP 3 169 898 B1 shows a serrated panel for a wind turbine rotor blade having asymmetrically shaped serrations. EP 3 205 874 B2 describes a serrated panel for a wind turbine rotor blade having a base portion for attachment to a surface of a wind turbine rotor blade and a plurality of serrations projecting from the base portion. The base portion has a corrugated external surface with valleys and crests. The crests are aligned with longitudinal midlines of the serrations and the valleys are aligned between serrations. The corrugated surface may be triangular, saw tooth shaped or sinusoidal. 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: an attachment section having a leading edge, an attachment surface for connecting the serrated panel to a trailing edge of a wind turbine rotor blade, a rear end, and an external surface opposite the attachment surface,a plurality of teeth, each tooth having a tip, a base which is arranged at the rear end of the attachment section, a longitudinal axis extending from the base to the tip, a pressure side surface, and a suction side surface,wherein the external surface of the attachment section for each tooth has a transition surface forming a transition between the leading edge and the pressure side surface of the tooth, whereinin a longitudinal section in a first plane that is perpendicular to the attachment surface and extends along the longitudinal axis of the tooth, the transition surface has a forward, concave section and a rearward, convex section, wherein the forward, concave section is arranged nearer to the leading edge of the attachment section than the rearward, convex section. The serrated panel is designed for being attached to a wind turbine rotor blade at a trailing edge of the wind turbine rotor blade. To this end, it has an attachment section with an attachment surface which can be connected to the wind turbine rotor blade, in particular by means of an adhesive, for example in liquid form or as an adhesive tape. The attachment section forms a front portion of the serrated panel. The front edge of the attachment section is referred to as leading edge. The other end of the attachment section is its rear end. The teeth extend from the rear end of the attachment section, where each tooth has its base which extends over a certain width of the rear end. The base may be formed by an imaginary, straight line which connects the recesses formed between adj acent teeth, in particular two forward ends of these recesses. Altogether, the plurality of teeth form a rear portion of the serrated panel. Each tooth has a tip and a longitudinal axis extending from the base to the tip. The longitudinal axis generally describes a longitudinal direction of the respective 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 of the teeth may be the same, so that all teeth have the same width,