The present disclosure relates to a blade noise reduction apparatus arranged at a trailing edge of a blade and reducing noise during rotation of the blade. The blade noise reduction apparatus includes an attachment unit combined with the trailing edge of the blade, and a sawtooth unit formed to protrude in a longitudinal direction of the attachment unit from the attachment unit, wherein the sawtooth unit includes a lower sawtooth unit including first sawteeth repeatedly arranged thereon, and an upper sawtooth unit including a second sawtooth having a length less than a length of the first sawtooth and arranged on an upper surface of each first sawtooth.

A horizontal axis wind turbine comprising a rotor having a plurality of blades, the rotor having a radius of at least 80 meters, the blades comprising: a root end and a tip end; a leading edge and a trailing edge; a shoulder between the root end and the tip end where a chord length defined between the leading edge and the trailing edge is at a maximum; wherein: Sol.sub.r is at least 0.0140 at 0.7R; Sol.sub.r is at least 0.0116 at 0.8R; Sol.sub.r is at least 0.0090 at 0.9R; Sol.sub.r being the combined radius specific solidity of the blades.

A horizontal axis wind turbine comprising a rotor having a plurality of blades, the rotor having a radius R of at least 80 meters, the blades comprising: a root end and a tip end, the blades extending in a spanwise direction from the root end to the tip end; a leading edge and a trailing edge, the blades extending in a chordwise direction along a chord from the leading edge to the trailing edge; a shoulder between the root end and the tip end where a chord length defined between the leading edge and the trailing edge is at a maximum; the blades being twisted between the root end and the tip end and the twist is defined by a twist distribution curve along the spanwise direction of the blades, each blade further comprising: an inboard region between the root end of the blade and the shoulder of the blade; an outboard region between a rotor radius 0.9R and the tip end of the blade; and a mid-board region located between the inboard region and the outboard region; a noise reduction feature in the mid-board region of the blade, the noise reduction feature projecting from the trailing edge and extending from a first radial position R1 toward the tip end; wherein the twist distribution curve comprises a first inflection point in the vicinity of the first radial position R1.

A method is provided for reducing the noise emission of a wind turbine rotor blade. The rotor blade has a leading edge, a trailing edge, a suction side, a pressure side and an attachment part at least partially on the pressure side. A pressure-side transition is present between the pressure side and the attachment part. The pressure-side transition is leveled by applying a leveling compound.

The present invention relates to a wind turbine rotor blade assembly comprising a rotor blade and a noise reducer (70) configured on the rotor blade. The noise reducer (70) comprises a plurality of aligned spine members (72), each spine member having a length and comprising a first section (74) extending along a first part of the length of the spine member, and a second section (76) extending along a second part of the length of the spine member, wherein the first section (74) has a higher stiffness than the second section (76).

Disclosed are methods and apparatuses for mitigating the formation of concentrated wake vortex structures generated from lifting or thrust-generating bodies and maneuvering control surfaces wherein the use of contour surface geometries promotes vortex-mixing of high and low flow fluids. The methods and apparatuses can be combined with various drag reduction techniques, such as the use of riblets of various types and/or compliant surfaces (passive and active). Such combinations form unique structures for various fluid dynamic control applications to suppress transiently growing forms of boundary layer disturbances in a manner that significantly improves performance and has improved control dynamics.

Disclosed are methods and apparatuses for mitigating the formation of concentrated wake vortex structures generated from lifting or thrust-generating bodies and maneuvering control surfaces wherein the use of contour surface geometries promotes vortex-mixing of high and low flow fluids. The methods and apparatuses can be combined with various drag reduction techniques, such as the use of riblets of various types and/or compliant surfaces (passive and active). Such combinations form unique structures for various fluid dynamic control applications to suppress transiently growing forms of boundary layer disturbances in a manner that significantly improves performance and has improved control dynamics.

A blade for a wind turbine can include an elongated and curved sheet having a curved root, a curved tip, a leading edge, and a trailing edge. The root and the tip can be rotated relative to each other such that the blade is twisted along its length. The root can include an edge having curved projections, the curved projections being distributed along a curvature of the root. A wind turbine can include a mounting element and a plurality of turbine blades. Each turbine blade can be attached to the mounting element closer to the trailing edge than to the leading edge such that an intersection of the leading edge and the root projects upstream from the wind turbine. A wind turbine generator assembly for converting wind into electrical energy can include a wind turbine and a generator. In addition, a support structure can support the wind turbine and generator.

A rotor for a wind, to a wind turbine and to a method for increasing the yield of a rotor of a wind turbine. In particular, a rotor for a wind turbine, comprising at least one rotor blade, having a rotor blade trailing edge and rotor blade leading edge extending between the rotor blade root and the rotor blade tip over a rotor blade length, a profile depth established between the rotor blade leading edge and the rotor blade trailing edge, and an adjustable pitch angle, wherein the rotor blade has at least one profile element which is arranged on the rotor blade trailing edge or in the region adjacent to the rotor blade trailing edge for increasing the profile depth by an enlargement value, characterized by a control unit for determining a pitch angle to be set, which is configured to determine the pitch angle to be set depending on the enlargement value.

Wind turbine rotor blade with reduced trailing edge noise A wind turbine rotor blade is described, the rotor blade extending in a spanwise direction between a root end and a tip end, and extending in a chordwise direction between a leading edge and a trailing edge. The rotor blade comprises a series of serrations projecting from the trailing edge, each serration extending from a base to a tip to define a length of the serration. The rotor blade also comprises a respective distinct set of fins associated with, and arranged adjacent to, each of the serrations, each fin projecting from a surface of the blade and extending between a leading end and a trailing end to define a length of the fin. Each set of fins comprises multiple fins whose trailing ends are in spanwise alignment with, and are located at or upstream of, the base of the serration associated with the set. For each set of fins, each fin of the set has a greater length than the serration associated with the set, and the trailing end of at least one fin lies between spanwise edges of the serration associated with the set.