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.

A rotor blade for a rotor, in particular of a wind power installation, having a rotor-blade length constituted between a root region and a rotor-blade tip, a rotor-blade depth constituted between a leading edge and a blunt trailing edge, a rotor-blade thickness constituted between a pressure side and a suction side, a suction-side trailing-edge region extending on the suction side and/or a pressure-side trailing-edge region extending on the pressure side, the suction-side trailing-edge region and/or the pressure-side trailing-edge region extending from the blunt trailing edge in the direction of the leading edge with an extent of less than 30%, in particular less than 20%, of the chord, and the suction-side trailing-edge region and/or the pressure-side trailing-edge region having at least one eddy generator.

Disclosed are vertical axis turbines comprising: a turbine shaft; a plurality of helicoidal blades mounted on the turbine shaft, each blade comprising a front face and a rear face; and a plurality of venturis, each venturi comprising a channel extending through each of the plurality of blades from the front face thereof to the rear face thereof.

Wind turbine blade having a length L, an airfoil with a chord C, and a first Gurney flap attached to the pressure or the suction surface of the airfoil near the trailing edge of the wind turbine blade. The first Gurney flap extends along at least 50% of the length of the outer ⅓.sup.rd of the wind turbine blade. By mounting the Gurney flap to the outer portion of the blade, the lift of the outer portion of the blade can be increased or decreased depending on the conditions in which the wind turbine is operating.

An optical analysis device for determining particulate matter includes three light sources having different wavelengths, an apparatus for combining the three transmitted light beams on a common optical path, a measurement volume, an optical axis in the forward scattering direction that defines the scattering angle 0°, a light absorption apparatus at 0° that absorbs unscattered light, and six detectors arranged at different specified angles which are as close as possible to 0° directly next to the light absorption apparatus, at a second scattering angle between 7° and 40°, at a third scattering angle between 41° and 70°, at a fourth scattering angle between 71° and 115°, at a fifth scattering angle between 116° and 145°, at a sixth scattering angle between 146° and 180°. A control and evaluation unit controls the light sources such that the scattered light is detected in a wavelength selective manner by the detectors.

Disclosed is a wind turbine blade assembly and a method for its manufacture. The wind turbine blade assembly comprises a leading edge, a trailing edge, a blade shell with a trailing portion, and a flatback profile component. The trailing portion has an outwardly curving arc shape and the flatback profile is positioned so as to cover the trailing portion of the blade shell.

Disclosed is a wind turbine blade comprising a shell body, a down conductor arranged in the shell body for conducting lightning current to ground, an electrical connector arranged in electrical connection with the down conductor, a lightning receptor element arranged at a surface of the shell body or outside the shell body, the lightning receptor element being in electrical connection with the electrical connector. A method for manufacturing a wind turbine blade with a lightning protection system is also provided.

A wind turbine blade includes a profiled contour with a leading edge and a trailing edge, and a chord extending between the leading edge and the trailing edge, along with a blade shell with a pressure side and a suction side, a first main spar cap integrated in the pressure side of the blade shell, a second main spar cap integrated in the suction side of the blade shell, and one or more shear webs connected between the first main spar cap and the second main spar cap. The blade shell includes at least a first load carrying structure arranged at the leading edge or the trailing edge and having a first extension, including a first primary extension on a first side of the chord, where the first primary extension is at least 60% of the first extension.

A lift control device actively controls the lift force on a lifting surface. The device has a protuberance near a trailing edge of its lifting surface, which causes flow to separate from the lifting surface, generating regions of low pressure and high pressure which combine to increase the lift force on the lifting surface. The device further includes a means to keep the flow attached around the protuberance or to modify the position of the protuberance in response to a command from a central controller, so as to provide an active control of the lift between a maximum value and a minimum value.