An arrangement to reduce noise of a wind turbine rotor blade is provided, including a wind turbine rotor blade and a noise reduction device. The noise reduction device includes a serrated extension for at least reducing noise generated from the wind turbine rotor blade, the noise reduction device attached to the trailing edge section. The serrated extension has a number of first and second teeth. The designs of the first and second teeth are differently compared to each other such that suction side noise and pressure side noise are both reduced by the teeth of the serrated extension. Advantageously, the first teeth and the second teeth are arranged in an alternating, periodic pattern and differ from each other by an angle of inclination with regard to a trailing edge streamline and or by its planform shape. Furthermore, a method to reduce noise of a wind turbine rotor blade is provided.

A wind turbine blade is described having a de-icing system which is arranged to heat at least a portion of the leading edge of the wind turbine blade, to prevent the formation of ice on the blade, or to remove any existing surface ice. The de-icing system comprises insulated flow channels which are arranged to circulate a heated fluid from a heating element to the tip end of the blade, and to de-ice the blade leading edge starting from the tip end towards the root end of the blade. The de-icing system is arranged to operate in the outboard portion of the blade, where the de-icing effect provides the most benefits to turbine operation. Further features of the de-icing system include an improved mounting arrangement of the de-icing system, an improved tip end configuration of the de-icing system, and providing portions of the de-icing system as double-walled inflatable insulating tubes.

A rotor for a wind turbine, in particular a wind turbine, having a power of more than 1 MW, to a hub for a rotor of a wind turbine and to a wind turbine. A rotor for a wind turbine, in particular a wind turbine having a power of more than 1 MW, comprising a primary rotor blade, wherein the primary rotor blade extends from a first root region to a first blade tip having a first longitudinal extension, a secondary rotor blade, wherein the secondary rotor blade extends from a second root region to a second blade tip having a second longitudinal extension, the first longitudinal extension being larger than the second longitudinal extension.

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.

The lengths and/or chords and/or pitches of wind turbine or propeller blades are individually established, so that a first blade can have a length/chord/pitch that is different at a given time to the length/chord/pitch of a second blade to optimize performance and/or to equalize stresses on the system.

A rotor hub for a wind power installation, with at least two flange portions each for receiving a rotor blade, wherein the rotor hub has a housing with a wall which is interrupted by the flange portions, wherein the housing has a wall region between two adjacent flange portions. A rotor arrangement for a wind power installation, and a wind power installation. A surface portion with cylindrical curvature is formed in the wall region.

A turbine assembly for a generator including a rotor that is operable to rotate about an axis; and a thrust absorbing member, wherein fluid is operable to enter the turbine assembly generally axially with regard to the axis of rotation of the rotor and to exit the turbine generally radially with regard to the axis of rotation of the rotor. The fluid is operable to contact the thrust absorbing member prior to contacting the rotor.

A wind turbine (1) comprising a tower (2), a nacelle (3) and a hub (7) is disclosed. The hub (7) comprises a blade carrying structure (4) with one or more wind turbine blades (5) connected to thereto. Each of the wind turbine blades (5) defines an aerodynamic profile having a thickness which varies along a length of the wind turbine blade (5). Each of the wind turbine blades (5) is connected to the blade carrying structure (4) via a hinge (6) at a hinge position of the wind turbine blade (5), each wind turbine blade (5) thereby being arranged to perform pivot movements relative to the blade carrying structure (4) between a minimum pivot angle and a maximum pivot angle. The hinge position is arranged at a distance from the inner tip end (5a) and at a distance from the outer tip end (5b), and the thickness, or the thickness-to chord ratio, at the hinge position is larger than the thickness, or the thickness-to-chord ratio, at the inner tip end (5a) and larger than the thickness, or the thickness-to-chord ratio, at the outer tip end (5b).

An engine is disclosed. The engine includes a rotary hub enclosing a manifold, blades radially distributed around the rotary hub, a combustion chamber at a distal end of each blade, an axle or shaft joined or fixed to the hub, and a generator operably connected to the axle or shaft. Each blade has a passage for air to flow to the combustion chamber and a fuel distribution conduit therein/thereon. The manifold connects a fuel supply conduit to the fuel distribution conduits. Each combustion chamber is configured to receive fuel and air from the corresponding fuel distribution conduit and passage, burn or detonate the fuel, and direct heated or expanded air and combustion gases in a direction that rotates the blades and the hub. The axle or shaft is configured to rotate with the hub. The generator is configured to convert a torque from the axle or shaft to electricity.

The invention relates to a wind turbine that includes a rotor rotating about a horizontal axis of rotation substantially parallel to the direction of the wind, the rotor having a front face facing into the wind and substantially perpendicular to the axis of the wind, and a rear face situated toward a support of the rotor. At least two distinct families of blades are distributed on the rotor, each family of blades including at least two blades having a free end and a blade root end connected to said rotor. Each family of blades includes a catching blade guiding the wind toward a force blade having a surface arranged substantially perpendicular to the axis of the wind, the blade root ends of each family of blades are successively offset on an exterior surface of the rotor along the axis of rotation thereof.