A rotor blade of a wind turbine including at least one vortex generator is provided. The vortex generator is attached to the surface of the rotor blade and is located at least partially within the boundary layer of the airflow flowing across the rotor blade. The vortex generator is exposed to a stagnation pressure, which is caused by the fraction of the airflow passing over the vortex generator and of which the magnitude depends on the velocity of the fraction of the airflow passing over the vortex generator. The vortex generator is arranged and prepared to change its configuration depending on the magnitude of the stagnation pressure acting on the vortex generator. Furthermore, an aspect relates to a wind turbine for generating electricity with at least one such rotor blade.

A wind turbine includes a blade. The blade includes a blade body; an active member mounted to the blade body and configured to move between a retracted position and an extended position to change an aerodynamic property of the blade; and a bladder which is configured to be connected to a pneumatic or hydraulic system of the wind turbine to move the active member when the bladder is filled by a fluid supplied by the pneumatic or hydraulic system, or when the fluid is removed from the bladder by the pneumatic or hydraulic system. The wind turbine includes a retaining means configured to prevent the active member from moving towards the extended position.

The present disclosure relates to a wind power installation having an aerodynamic rotor with at least one rotor blade, wherein the rotor blade has an active flow control device, which is designed to actively influence a flow over the rotor blade, wherein the flow control device comprises an opening in a rotor blade surface, referred to as a rotor blade surface opening, wherein the flow control device is configured to draw off and/or blow out air through the rotor blade surface opening air by way of a controllable air flow, wherein the wind power installation has a controller which is configured to control an amount of the controllable air flow through the rotor blade surface opening according to at least one of the following rules: if a rotational speed threshold value of a rotational speed of the rotor is exceeded, increasing the maximum controllable air flow successively with increasing rotational speed, if a torque threshold value of a torque of the rotor is exceeded, increasing the maximum controllable air flow successively with increasing torque.

The invention is about a method for controlling a wind turbine with a variable rotor area. The wind turbine comprises a rotor with one or more rotor blades which are arranged hinged at an adjustable pivot angle, where the variable rotor area depends on the pivot angle, and where the pivot angle is adjustable dependent on a variable pivot force provided by a pivot actuator. The method comprises determination of a maximal pivot force based on the input operational parameter which relate to an actual load or a predicted load of the wind turbine, determining a desired pivot force based on a desired operational performance of the wind turbine, and determining a pivot force set-point to be applied to the pivot actuator based on the desired pivot force so that the pivot force set-point is equal to or below the maximal pivot force.

A friction limiting turbine gyroscope is a compact and efficient means to convert the energy of a moving fluid into electrical energy. The gyroscope's flywheel rotates when a fluid passes through its spokes while magnets located along the perimeter act upon proximate movable field coils to produce electricity. The spokes of the flywheel are optimized for the flow and density of the fluid with the ability to trans mutate using shaped memory alloys as well as rotate about their center of pressure allowing the flywheel to capture more of the energy from the fluid passing over their surfaces in all conditions. Mechanical energy losses are reduced because of the inherent stabilizing effects created by the gyroscope. Because of the stabilization, a magnetic bearing field effectively supports the gyroscope eliminating mechanical interference in rotation.

A friction limiting turbine gyroscope is a compact and efficient means to convert the energy of a moving fluid into electrical energy. The gyroscope's flywheel rotates when a fluid passes through its spokes while magnets located along the perimeter act upon proximate movable field coils to produce electricity. The spokes of the flywheel are optimized for the flow and density of the fluid with the ability to trans mutate using shaped memory alloys as well as rotate about their center of pressure allowing the flywheel to capture more of the energy from the fluid passing over their surfaces in all conditions. Mechanical energy losses are reduced because of the inherent stabilizing effects created by the gyroscope. Because of the stabilization, a magnetic bearing field effectively supports the gyroscope eliminating mechanical interference in rotation.

A wind turbine (1) comprising a tower (2), a nacelle (3) mounted on the tower (2) via a yaw system, a hub (4) mounted rotatably on the nacelle (3), the hub (4) comprising a blade carrying structure (5), and one or more wind turbine blades (6) connected to the blade carrying structure (5) via a hinge (7) is disclosed. Each wind turbine blade (6) is thereby arranged to perform pivot movements relative to the blade carrying structure (5) between a minimum pivot angle and a maximum pivot angle. The blade carrying structure (5) is provided with one or more elements (8) configured to improve aerodynamic properties of a surface of the blade carrying structure (5) by increasing a lift and/or decreasing a drag of the blade carrying structure. The increase in lift and/or decrease in drag varies as a function of angle of attack (AOA) between the blade carrying structure (5) and the incoming wind.

A horizontal axis wind turbine (1) with a wind turbine blade (5) is disclosed, the wind turbine blade (5) comprising a hinge (6) arranged to connect the wind turbine blade (5) to a blade carrying structure (4) of the wind turbine (1), at a non-zero distance from an inner tip (5a) and at a non-zero distance from an outer tip (5b) of the wind turbine blade (5). An outer blade part (7) is arranged between the hinge region and the outer tip (5b), and an inner blade part (8) is arranged between the hinge region and the inner tip (5a). The outer blade part (7) extends from the hinge region along a first direction and the inner blade part (8) extends from the hinge region along a second direction, and the first direction and the second direction form an angle, α, there between, where 0°<α<90°.

An extendable wind turbine blade for being extended in length during operation thereof, the wind turbine blade having an exterior surface with a root region and an airfoil region and comprising a first blade segment including a first portion of the exterior surface, a second blade segment including a second portion of the exterior surface, and a connection mechanism connecting the blade segments, and being configured to bring the wind turbine blade to a retracted state, in which the portions of the exterior surface are flush and adjoining, when the wind turbine blade operates above a threshold rotational speed and to bring the wind turbine blade to an extended state, in which the portions of the exterior surface are disconnected and the blade length is at least 101% of the blade length in the retracted state, when the wind turbine blade operates below the threshold rotational speed.

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.