The present disclosure relates to a method of optimizing a rotor blade of a wind turbine, wherein said rotor blade extends from a rotor-blade coupling to a rotor-blade tip in a rotor-blade longitudinal direction with a rotor-blade length, having an aerodynamical profile extending between a leading edge and a trailing edge, wherein said method comprises the following steps: designing of said rotor blade for design environmental conditions including at least one design air density, with said designing comprising providing a sound-protection means, the sound protection means comprising at least one bristle, within a blade external region of said rotor blade the latter being defined as the 50% of said rotor-blade length abutting said rotor-blade tip; providing an air density at the installation site of said wind turbine; comparing said air density with said design air density; and increasing the induction factor by increasing a density factor of said sound-protection means when said air density is lower than said design air density.

Provided is an arrangement for discharging current due to a lightning stroke at a tip add-on of a rotor blade of a wind turbine, the arrangement including a conductor adapted to conduct the current due to the lightning stroke; an insulation arranged around the conductor, the insulation with the conductor being arrangeable within the tip add-on.

A wind turbine blade assembly, includes a wind turbine blade and a lightning protection system including an internal down conductor inside the wind turbine blade and multiple air termination devices having a receptor, which is electrically conductively coupled to the down conductor, wherein the length of the wind turbine blade assembly is divided into a first part having the internal down conductor and spanning from the blade root to at least one first air termination device and a second part spanning from the first air termination device to the assembly tip, wherein the lightning protection system further includes a second air termination device in the second part, and an external, electrically conductive strip extending between a pair of a first and a second air termination devices in the second part and being electrically conductively coupled to their receptors.

Provided is an arrangement for discharging current due to a lightning stroke at a tip add-on of a rotor blade of a wind turbine, the arrangement including a conductor adapted to conduct the current due to the lightning stroke; an insulation arranged around the conductor, the insulation with the conductor being arrangeable within the tip add-on.

A fluid flow powered system for generating electrical power including a rotating turbine blade assembly comprising an outer rim, a tension airfoil central hub assembly, tension elements extending between the outer rim and the tension airfoil central hub assembly, and a plurality of turbine blades secured to the tension elements. A rim engagement wheel is rotationally driven by the outer rim. Rotation of the wheel drives an electric power generator. The turbine blade assembly can be rotationally driven by at least one of wind and water. The wheel, independently or in conjunction with additional wheels can provide at least one of axial support and radial support to the turbine blade assembly during operation.

A wind turbine blade having a length of at least 100 meters comprising: a root end (and a tip end, the blade extending in a spanwise direction from the root end to the tip end, the root end having a substantially circular profile with a root end diameter, and a profile of the blade transitioning into a lift generating profile moving in the spanwise direction from the root end towards the tip end; a leading edge and a trailing edge, the blade extending in a chordwise direction along a chord from the leading edge to the trailing edge; an inboard region extending in the spanwise direction from the root end to a distal end, the inboard region having a length defined between the root end and the distal end; wherein in the inboard region, the chord of the blade is within 5% of the root end diameter and the inboard region has a length of at least 10% span of the blade.

A blade for a rotor of a wind turbine, the blade comprising: an inboard portion; an outboard portion connected to the inboard portion, wherein the outboard portion is deflectable by a variable sweep angle in an edgewise direction of the blade; and a passive mechanism configured to adjust the sweep angle in response to an amount of flapwise moment acting on the blade, such that the magnitude of the sweep angle increases in response to an increased flapwise moment, and decreases in response to a decreased flapwise moment.

A wind turbine rotor blade extension fitting element, which extension fitting element is designed as a rotor blade rib with a recess and which can be pushed onto the rotor blade tip of a rotor blade to be extended, in such a way that the rotor blade tip protrudes through the recess and contacts the circumferential surface of the recess in an positive-locking manner. The extension fitting element has, on its outer circumference, an outer circumferential surface onto which a shell-like rotor blade extension can be pushed in an positive-locking manner. A core of the extension fitting element has slits and/or boreholes which, for stabilization, are filled with a material that has a higher strength and/or stiffness than the material of the core. In this way, the extension fitting element is strengthened for the transfer of high loads.

There is provided a wind turbine blade having a root end, a tip end, a blade shell, a lightning protection system and an integrated web-down conductor. The integrated web-down conductor comprises: a down conductor forming part of the lightning protection system: electrical insulation surrounding the down conductor; and a web that surrounds the electrical insulation so as to enclose the down conductor and electrical insulation and is coupled to the blade shell.

A wind turbine blade including a shell structure defining a leading edge and a trailing edge, and an upwind shell and a downwind shell joined along at least one of the leading edge or the trailing edge. The shell structure includes an assembly of preformed parts processed into a collection of prefabricated laminates. The invention also includes a method of manufacturing a wind turbine blade, the method includes processing a number of preformed parts into a collection of prefabricated laminates and assembling the collection of prefabricated laminates to build a shell structure defining a leading edge and a trailing edge.