Abstract: The present invention relates to a damper unit for damping oscillations of a tower structure when secured thereto, the damper unit comprising a damper unit structure adapted for attachment to the tower structure, a pendulum structure, a suspension arrangement for suspending the pendulum structure from the damper unit structure such that the pendulum structure is allowed to displace from a neutral position for the pendulum structure, the suspension arrangement comprising one or more wires for suspending the pendulum structure, a sensor adapted for measuring oscillations of the tower structure, and tuning means configured for adjusting the natural frequency of the suspended pendulum structure in response to measured oscillations of the tower structure. The present invention further relates to an associated method.

Abstract: A system and method are provided for controlling a wind turbine. Accordingly, a controller of the wind turbine determines a thermal gradient of the tower due to solar heating. The controller also determines a displacement of a reference point of the wind turbine from a nominal position resulting from a thermal expansion of a portion of the tower. The displacement includes a displacement magnitude and a displacement direction. The displacement direction is in a radial direction opposite of a maximal peak of the thermal gradient. Additionally, the controller determines a correction factor corresponding to the displacement and a setpoint for a component of the wind turbine based, at least in part, on the correction factor. Finally, an operating state of the wind turbine is established based, at least in part, on the setpoint.

Abstract: A propeller control unit (PCU) has: a pitch angle actuator; a valve operable to selectively fluidly connect the pitch angle actuator with a source of oil for controlling pitch angles of blades of a propeller and with a drain line for draining oil out of the pitch angle actuator for feathering the blades; and a bypass line having an inlet hydraulically between the valve and an inlet of the drain line, the bypass line having an outlet hydraulically between the inlet of the drain line and an outlet of the drain line.

Abstract: Systems and methods for harnessing hydro-kinetic energy. The system includes a single central axle, a plurality of vanes, and a generator. The plurality of vanes may be configured to rotate about the central axle. Each vane may include a frame and a panel rotatably attached the frame. The panel may comprise a plurality of channels having a C-shaped cross-section. Movement of surrounding water may cause the panel to rotate relative to the frame between an open and closed position. The generator may be configured to convert the rotational motion of the plurality of vanes into electrical energy.

Abstract: An intentional fluid manipulation apparatus (IFMA) assembly with a first thrust apparatus that imparts a first induced velocity to a local free stream flow during a nominal operation requirement. The first thrust apparatus creates a streamtube. A second thrust apparatus is located in a downstream portion of the streamtube. The second thrust apparatus imparts a second induced velocity to the local free stream flow. The second induced velocity at the location of the second thrust apparatus has a component in a direction opposite to the direction of the first induced velocity at the location of the second thrust apparatus.

Abstract: An apparatus and method an engine component for a turbine engine comprising an outer wall bounding an interior and defining a pressure side and an opposing suction side, with both sides extending between a leading edge and a trailing edge to define a chord-wise direction, and extending between a root and a tip to define a span-wise direction, at least one cooling passage located within the interior, a set of cooling holes having an inlet fluidly coupled to the cooling passage, an outlet located on one of the pressure side or suction side, with a connecting passage fluidly coupling the inlet to the outlet.

Abstract: A crank angle detection device for an engine capable of achieving downsizing and enhancing appearance of the engine is provided. A crank angle detection device for an engine that includes a pulsar ring including a plurality of detection portions and rotating coaxially with a crank shaft of the engine, and a sensor detecting a passage state of the detection portions. Here, the pulsar ring is fixed to a crank web of the crank shaft. A weight for adjusting inertia balance of the crank shaft is fixed to the crank web arranged close to an end of the crank shaft in an axial direction. The weight has a shape obtained by increasing thickness of a part of the pulsar ring.

Abstract: The invention relates to a method of determining the vertical profile of the wind speed upstream from a wind turbine (1), wherein wind speed measurements are performed by a LiDAR sensor (2), then the exponent ? of the power law is determined by an unscented Kalman filter and measurements, and the exponent ? is applied to the power law in order to determine the vertical wind speed profile.

Abstract: Provided is a wind turbine blade spar cap for a wind turbine blade for a wind turbine, the wind turbine blade including a down conductor, the wind turbine blade spar cap including at least one carbon element and at least one conductive layer, wherein the at least one carbon element and the at least one conductive layer are electrically connected, and at least one conductive profile to electrically connect the at least one conductive layer to the down conductor of the wind turbine blade, wherein the conductive profile is electrically connected to the at least one conductive layer and wherein the conductive profile is arranged at the wind turbine blade spar cap. Also provided is a wind turbine blade including a spar cap and a wind turbine including wind turbine blades.

Abstract: A method may include obtaining a normal set point of a solar panel and a wind velocity measurement corresponding to wind that affects the solar panel. The method may include determining an allowable range of tilt angles according to a first lookup table that describes a relationship between the wind velocity measurement and the allowable range of tilt angles. The method may include identifying whether the normal set point of the solar panel is outside of the allowable range of tilt angles, and responsive to identifying that the normal set point of the solar panel is outside of the allowable range of tilt angles, determining a temporary stow set point. The method may include rotating the solar panel to the temporary stow set point.

Abstract: A bearing arrangement for a wind turbine including a bearing housing and a drive shaft, whereby the drive shaft is arranged within the bearing housing in an axial direction along a longitudinal axis of the bearing housing, the bearing arrangement further comprising a downwind bearing and an upwind bearing as radial fluid bearings, whereby the downwind bearing and the upwind bearing are arranged between the bearing housing and the drive shaft is provided. The downwind bearing and/or the upwind bearing includes a lubricant flooded chamber, in which multiple radial bearing pads are arranged about the drive shaft, whereby the lubricant flooded chamber is sealed against the drive shaft, an internal space of the bearing housing and an outside of the bearing housing is also provided.

Abstract: A rotor blade for a wind turbine, to a wind turbine comprising a tower, a nacelle and a rotor, and also to a wind farm. The rotor blade comprises an inner blade section that extends from a rotor blade root in the longitudinal direction of the rotor blade, and a trailing edge segment, arranged on the inner blade section, for increasing the profile depth of the rotor blade along a section in the longitudinal direction of the rotor blade. The rotor blade has a pressure-side surface and a suction-side surface, which are each formed in certain regions by parts of the inner blade section and of the trailing edge segment. One or more air outlets and air inlets extending substantially in the longitudinal direction of the rotor blade are formed on both the pressure-side surface and the suction-side surface of the rotor blade, in the region of the trailing edge segment, said air outlets and air inlets being interconnected in a fluid-guiding manner.

Abstract: A sensor device for measuring flow-separation on an aerodynamic element, including a number of compliant elements with aerodynamic and/or structural properties designed to allow flow-induced vibrational motion in an air current and a sensor-element designed to measure vibrations of the number of compliant elements is provided. Further provided is an aerodynamic element, e.g. a wind turbine blade or an airfoil, with such sensor device, a method for controlling the angle of attack of an aerodynamic element, a controlling device and a wind turbine.

Abstract: Embodiments are directed to systems and methods for providing a control link for an aircraft in which the control link comprises an impact-resistant structure with a redundant load path. The control link has an inner structure that is sized to carry the anticipated load of the flight control system and to meet all safety factors. The control link also has an outer structure that is sacrificial and configured to absorb impact damage during operation, thereby protecting the inner structure. The outer structure is also designed to carry the anticipated load of the flight control system on its own, independent of the inner structure, and to meet all safety factors. If the outer structure fails, the inner structure allows for continued safe operation of the flight control system. The space or cavity between the inner and outer structures may be filled with a material, such as a closed-cell foam, to improve the impact resistance of the outer structure.

Abstract: Embodiments herein describe a method and associated controller for a wind turbine. The method comprises determining one or more characteristics of a sensor signal received from a mechanical sensor of the wind turbine; determining, based on the one or more characteristics of the sensor signal, an icing condition of the wind turbine; and controlling operation of one or more wind turbine systems based on the determined icing condition.

Abstract: Composite components and methods for forming composite components are provided. For example, a composite component of a gas turbine engine comprises a composite material, a plurality of piezoelectric fibers, and an anti-icing mechanism. The anti-icing mechanism is in operative communication with the piezoelectric fibers such that the anti-icing mechanism is activated by one or more electrical signals from the piezoelectric fibers. In exemplary embodiments, the composite component is a composite airfoil and the anti-icing mechanism is one or more heating elements. Methods for forming composite components may comprise forming piezoelectric plies comprising piezoelectric fibers embedded in a matrix material; forming reinforcing plies comprising reinforcing fibers embedded in the matrix material; laying up the piezoelectric and reinforcing plies to form a ply layup; and processing the ply layup to form the composite component.

Abstract: A rotor craft changes a torsional angle of a blade by driving an actuator. The rotor craft includes a plurality of torsion applying mechanisms that each twist a proximal end portion of a corresponding blade relative to a distal end portion of the corresponding blade about a center axis A of the blade. Each blade includes a spar having a proximal end portion connected to a hub and a skin in which the spar is inserted, such that a distal end portion of the skin and a distal end portion of the spar are connected to each other, and such that other portions of the skin than the distal end portion are rotatable relative to the spar about a center axis of the spar. The hub includes a hub body mounted to a main rotor shaft, and a hub arm that connects the spar to the hub body.

Abstract: A method of operating a marine vessel hybrid propulsion system having a propulsion shaft and a propeller, an internal combustion piston engine in force transmission connection with the propulsion shaft, and an electric motor-generator in force transmission connection with the propulsion shaft and/or with the piston engine. The internal combustion piston engine can be started by applying electric power from an on-board power source to the electric motor-generator and rotating the internal combustion piston engine by the electric motor-generator and rotational speed of the internal combustion piston engine is accelerated to a predetermined limit rotational speed without attempting to start the internal combustion piston engine, and only after the rotational speed of the internal combustion piston engine reaches the predetermined limit rotational speed, the internal combustion piston engine is started.

Abstract: Described is a system for monitoring deflection of turbine blades of a wind turbine comprising a tower. The system comprises a position detecting apparatus mounted to the wind turbine, the position detection apparatus comprising position detection components each detecting a presence or absence of a corresponding one of the segments of the turbine blades; and a deflection controller configured to receive the presence or absence detection and to use the presence or absence detection to determine a distance of each of the segments of the turbine blades relative to the tower, whereby the distance of each of the segments of the turbine blades relative to the tower is representative of the deflection of the turbine blades.

Abstract: Provided is a wind turbine blade for a wind turbine, the wind turbine blade including a root, a tip, a trailing edge, a leading edge and at least two beams including carbon fiber-reinforced plastic and being spaced apart from one another, wherein the at least two beams are arranged in the wind turbine blade in the longitudinal direction of the wind turbine blade at the trailing edge or within a distance of 25% of the width from the trailing edge, whereby the at least two beams are electrically connected to one another by at least one electrically conductive member and at least one of the at least two beams and/or at least one of the at least one electrically conductive member is configured to be connected to a down conductor of the wind turbine.

Abstract: The present invention relates to a method of identifying an electrical contact fault in a wind turbine blade electrical heating system, comprising inserting a predetermined enforced off cycle between or within a switching duty cycle, wherein the switching duty cycle controls the switching of one or more electrical contacts in the electrical heating system, measuring a current consumption during the predetermined enforced off cycle, determining if the measured current consumption exceeds a predetermined threshold, and wherein if the measured current consumption exceeds the predetermined threshold shutting down at least part of the electrical heating system. The present invention also relates to a wind turbine with one or more wind turbine blades that can identify an electrical contact fault.

Abstract: A method for protecting a wind turbine from extreme and fatigue loads associated with high wind speed events includes receiving, via a wind turbine condition estimator programmed in a turbine controller of the wind turbine, operating data indicative of current wind turbine operation. Further, the method includes determining, via the wind turbine condition estimator, a plurality of estimated wind turbine conditions at the wind turbine by solving a control algorithm having one or more equations using the operating data. The estimated wind turbine conditions include, at least, an estimated wind speed at the wind turbine and a loading proxy of the wind turbine. As such, the method includes implementing, via the turbine controller, a corrective action only when each of the estimated wind turbine conditions indicates that one or more loading conditions of the wind turbine exceeds a predetermined limit.

Abstract: Embodiments of the present disclosure include a retrofit auxiliary nacelle yaw position control system that enables advanced nacelle yaw position control of a wind turbine by comparing a desired nacelle yaw position signal with the actual nacelle yaw position and generating a virtual relative wind direction signal that is provided to the existing turbine control unit. This method and system enable implementation of wake steering, collective yaw optimization and dynamic yaw optimization of a collection of wind turbines referred to as a wind plant. Modification of the existing turbine control unit is not required, greatly simplifying the implementation process of advanced yaw control strategies on existing wind plants.

Abstract: Provided is a method for adjusting a pitch angle of a rotor blade connected to a rotor of a wind turbine, the method includes: pitching the rotor blade towards a target blade pitch angle, the manner of pitching depending on a load on a pitch bearing and/or an azimuthal position of the rotor.

Abstract: Embodiments of the present disclosure include a data processing and control augmentation system capable of identifying overloading of one or more wind turbine assemblies and providing information to a wind farm controller to reduce a power output of each overloaded turbine. The augmentation system thus reduces the power output of each overloaded turbine and, in turn, reduces loads applied to the wind turbine assembly, such as for a period of time until conditions favorably change. A described analysis of the present disclosure is able to utilize several incoming data streams from sensors so arranged to measure wind effects on blades to calculate and compare cyclic loads to threshold limits to o keep the loads within design limits. The control strategy reduces premature failure of components within the wind turbine assembly, and can be applied across an entire wind farm, even with only a subset of wind turbine assemblies being retrofitted.

Abstract: A fan device used with respect to a computing device. The fan device includes at least two fans that provide airflow for the computing device and a controller that adjusts the fans' speeds in an attempt to avoid harmonic vibrations of the at least two fans. The fan device may include at least one sensor, and the controller may adjust the fans' speeds based at least on information from the sensor(s) in the attempt to avoid the harmonic vibrations. The attempt to avoid the harmonic vibrations may also attempt to mitigate one or more of turbulence, pressure, over-heating, power consumption, or noise in, by, or around the computing device. Reversal of airflow may also be used. A fan bar that enables isolation of ground return noise may also be used. The controller may use sums of primes calculations, phase analysis, common divisor calculations, and the like. Also, associated methods.

Abstract: A wind turbine controller includes a thrust limiter for controlling the thrust of the blades of wind turbine using an estimate of the air density at the wind turbine. In one embodiment, the controller receives the blade flap load indicating the current load on one of the blades which varies linearly to the air density experienced by the wind turbine. In one embodiment, the controller determines the mean of a plurality of the blade flap load values measured during a predefined time period. Using a transfer function, the controller converts the mean of the blade flap loads to an estimate of the air density at the turbine. Generally, higher air density results in greater loads on the blades while lower air density results in lower loads on the blades.

Abstract: A method for wind turbine tower damping is disclosed, as well as an associated controller and wind turbine. The method comprises generating, using at least a first sensor signal, a first pitch reference signal for one or more rotor blades of a wind turbine during partial load operation. The method further comprises determining, using at least a second sensor signal, dynamic state information for a tower of the wind turbine. The method further comprises generating a second pitch reference signal by adapting the first pitch reference signal using the dynamic state information. The method further comprises selecting a maximum pitch reference signal from the second pitch reference signal and a saturation pitch reference signal. The method further comprises communicating the maximum pitch reference signal to control a pitch of the one or more rotor blades.

Abstract: Described herein are various systems and techniques for deterring wildlife from an area proximate a windmill. A flying wildlife emitter may be utilized for such techniques. The flying wildlife emitter may output soundwaves to deter wildlife, such as birds or bats, from entering an area around the windmill. The flying wildlife emitter may include a speaker for producing sounds as well as a controller and sensors for determining conditions around the windmill and for controlling the sound produced by the speaker.

Abstract: A method for managing icing conditions on a rotary aircraft via one or more ice protection controllers. The method includes steps for receiving an icing condition signal from an icing rate sensor at an ice protection controller, determining, in response to the icing condition signal, a de-icing signal based at least in part a liquid water content (LWC). The method further includes steps for transmitting, via a digital communication bus disposed in at least part of a slip ring assembly, the de-icing signal to a upper distributor to cause the upper distributor to transmit power to one or more heating elements for a respective rotor blade.

Abstract: Adjustment and/or drive units that can be used in wind turbines to set the azimuth angle of the wind turbine nacelle or the pitch angle of the rotor blades, wherein such an adjustment and/or drive unit has at least two actuating drives for rotating two assemblies, which are mounted for rotation relative to each other, and has a control device for controlling the actuating drives, which control device controls the actuating drives in such a way that the actuating drives are braced in relation to each other during the rotation of the two assemblies and/or at a standstill of the assemblies. The invention further relates to a wind turbine having such an adjustment and/or drive unit and to a method for controlling such an adjustment and/or drive unit.

Abstract: A blade angle feedback ring assembly for an aircraft engine propeller having adjustable angle blades is provided. The feedback ring assembly comprises a feedback ring coupled to rotate with the propeller, the engine configured such that a first electrically-conductive path is defined between the propeller and the engine via the feedback ring, and an electric current conduction element provided between the propeller and the engine to define a second electrically-conductive path between the propeller and the engine in parallel to the first path, the second electrically-conductive path configured with a lower electrical resistance to conduction between the propeller and the engine than the first electrically-conductive path.

Abstract: A wind turbine rotor blade is provided with a rotor blade root region, a rotor blade tip region, a pressure side, a suction side, a leading edge, a trailing edge and at least one flange along a longitudinal direction of the rotor blade. Furthermore, a deflecting unit is provided between one end of the at least one flange and the rotor blade tip region. At least one air scoop is provided on the flange, wherein the air scoop protrudes in a region between a first and second flange.

Abstract: A wind turbine with a rotor blade, wherein the rotor blade includes a pneumatically activatable aerodynamic device and the wind turbine includes a pressure supply system for controlling the activatable aerodynamic device is provided. The pressure supply system includes a pressurized air supply system, a pressurized air transmission system with pressure lines for transmitting the supplied pressurized air from the pressurized air supply system to the aerodynamic device, and at least one pneumatic actuator for activating the aerodynamic device.

Abstract: Provided are a wind farm noise prediction method, apparatus and system. The method comprises: collecting, in real time, a wind speed at a site of at least one wind turbine generator system, which impacts noise at a noise detection point, in a wind farm; according to a noise acoustic power level database and a system database, respectively calculating a noise acoustic power level, at the collected wind speed, of each wind turbine generator system from among the at least one wind turbine generator system; according to a wind farm noise propagation database, respectively calculating a noise propagation loss value, at the collected wind speed, of each wind turbine generator system; and using the noise acoustic power level and the noise propagation loss value of each wind turbine generator system to calculate a total noise acoustic pressure level at the noise detection point.

Abstract: A method for protecting a wind turbine from an extreme change in wind direction includes receiving a wind direction and/or a wind speed at the wind turbine. When a change in the wind direction or the wind speed exceeds a predetermined threshold, the method includes determining a margin to stall and/or zero lift of the at least one rotor blade of the wind turbine as a function of an angle of attack or change in the angle of attack at a blade span location of at least one rotor blade of the wind turbine. The method also includes implementing a corrective action for the wind turbine (without shutting down the wind turbine) when the margin to stall and/or zero lift exceeds a predetermined value so as to avoid stall and/or negative lift on the at least one rotor blade during operation of the wind turbine.

Abstract: A method for operating a wind turbine includes determining at least one wind condition of the wind turbine for a plurality of time intervals. The method also includes determining a status of the wind turbine at the beginning of each of the plurality of time intervals. Further, the method includes determining at least one vibration parameter of the wind turbine for one or more preceding time intervals of the plurality of time intervals. Moreover, the method includes predicting whether a trip event is imminent based on the at least one wind condition, the status of the wind turbine at the beginning of each of the plurality of time intervals, and the vibration parameter. Thus, the method further includes implementing a control action for the wind turbine so as to prevent the trip event.

Abstract: A method for controlling a wind power plant connected to an electrical grid, the wind power plant comprising at least one wind turbine generator and a power plant controller, the power plant controller comprising a signal controller for controlling an electrical parameter with a gain, the method comprising, measuring at least one electrical parameter in the electrical grid , determining an internal signal value at least partially based on the at least one electrical parameter, comparing the internal signal value with a saturation value, and if the internal signal value exceed the saturation value, increasing the gain of the signal controller to a first gain value, in order to decrease a rise time for a slope for the electrical parameter in the electrical grid.

Abstract: The invention relates to a method for acquisition and modelling of an incident wind field by a LiDAR sensor. Acquisition and modelling include a step of estimating the wind amplitudes and directions for a set of discretized points, and a step of incident wind field reconstruction in three dimensions and in real time. The invention also relates to a method of controlling and/or monitoring a wind turbine equipped with such a LiDAR sensor from the incident wind field reconstructed in three dimensions and in real time.

Abstract: A method, system, and apparatus are provided for optimizing control of the rotational speed of a fan in a vehicle so as to reduce the aerodynamic drag of a vehicle in a given operating parameter, and accordingly, to improve fuel efficiency of operation of the vehicle. Certain exemplary embodiments include determining an optimized speed of rotation of a cooling fan of the vehicle for reducing overall fuel demand in given operating conditions, and controlling rotation speed of the fan at the optimized speed in order to minimize fueling demand of a prime mover of the vehicle.

Abstract: A system and method are provided for controlling a wind turbine of a wind farm. Accordingly, a controller determines a performance differential for the wind turbine at multiple sampling intervals of a yaw event. The controller determines a trendline for the wind turbine correlating the performance differential to a deviation of a wind direction at each of the multiple sampling intervals from an first yaw angle. A difference between an angle associated with the vertex of the trendline and the first yaw angle are utilized by the controller to determine a yaw angle offset. The yaw angle offset is used to adjust a second yaw angle of the wind turbine.

Abstract: An example hybrid aircraft propulsion system includes one or more parallel propulsion units, each of the parallel propulsion units comprising: a first propulsor; a gas turbine engine configured to drive the first propulsor; and an electrical machine selectively configurable to: generate, for output via one or more electrical busses, electrical energy using mechanical energy derived from the first propulsor or the gas turbine engine; and drive the first propulsor using electrical energy received via the one or more electrical busses; and one or more series propulsion units, each of the series propulsion units comprising: a second propulsor; and an electrical machine selectively configurable to: generate, for output via the one or more electrical busses, electrical energy using mechanical energy derived from the second propulsor or the gas turbine engine; and drive the second propulsor using electrical energy received from one or more electrical busses.

Abstract: A wind turbine includes at least one wind speed sensor, a number of pitch-adjustable rotor blades, and a control system for changing the pitch of the rotor blades and/or a generator torque. The the control system determines at time intervals an error parameter as the difference between an estimated wind speed and a measured wind speed as measured by the wind speed sensor. Then, based on a number of pre-defined wind speed intervals, a group of error parameters is obtained over time for each wind speed interval. For each wind speed interval and for each group of error parameters a wind speed offset is determined based on the average of the error parameters within the group which wind speed offsets are used in adjusting the measured wind speed.

Abstract: Systems and methods are contemplated for favorably improving flight dynamics of aircraft, including enhanced aerodynamic braking and improved flight maneuverability. Air braking systems selectively position a first set of blades at a negative thrust pitch to product a net negative thrust across first and second sets of blades, while balancing torque of the drive shafts to zero. First and second sets of IBC blades can be driven by the same shaft or torque-linked shafts. Flight maneuver systems operate a powerplant at a high power mode, and dissipate the energy from the high power output by positioning a first set of IBC blades at a low efficiency pitch while maintaining constant thrust. As increased or rapid flight maneuverability is required, the first set of blades is positioned toward a high efficiency pitch to instantly increase thrust to the aircraft without requiring a related increase in energy output from the powerplant.

Abstract: A system and method are provided for determining a geographic location of a tower top pivot point (TPP) of a wind turbine tower having a nacelle that includes a machine head and rotor at a top thereof. At least one rover receiver of a global navigation satellite system (GNSS) is configured at a fixed position on the nacelle. A plurality of 360-degree yaw sweeps of the nacelle are conducted and the geo-location signals received by the rover receiver during the yaw sweeps are recorded. With a controller, the geo-location signals are converted into a circular plot and a radius of the plot is determined, the radius being a distance between the rover receiver and the TPP. Based on a GNSS geo-location of the rover receiver and the radius, a geo-location of the TPP is computed.

Abstract: A blade includes an airfoil defined by a pressure side outer wall and a suction side outer wall connecting along leading and trailing edges and form a radially extending chamber for receiving a coolant flow. A rib configuration may include: a leading edge transverse rib connecting the pressure side outer wall and the suction side outer wall and partitioning the radially extending chamber into a leading edge passage within the leading edge of the airfoil and a central passage adjacent to the leading edge passage. One or both camber line ribs connect to a corresponding pressure side outer wall and suction side outer wall at a point aft of the leading edge transverse rib causing the central passage to extend towards one or both of the pressure side outer wall and the suction side outer wall, resulting in a flared center cavity aft of the leading edge.

Abstract: A sleeve connecting a blade to the hub of a rotor of a rotary wing aircraft. The sleeve has a leading edge and a trailing edge, together with a protuberance arranged on the trailing edge. The dimensions of the protuberance are linked to the dimensions of the sleeve. The presence of the protuberance serves to improve the aerodynamic behavior of the sleeve and of the rotor during rotation of the rotor while the aircraft is moving forwards, both when the sleeve is advancing and when it is retreating. The presence of the protuberance also serves to reduce the vibration generated by a wake of the rotor on a tail boom or on a horizontal and/or vertical stabilizer of the aircraft.

Abstract: Embodiments herein describe a system used to estimate the presence of water on a sensor. A parameter maintains a wind sensor temperature. The parameter can be tracked and evaluated to indicate a likelihood of water on the sensor. Alternatively, or in combination with the above, the sensor is adjusted intentionally or deactivated and reactivated to track a parameter response which is then used to indicate a likelihood of water on the sensor.

Abstract: The invention relates to a method for monitoring a wind farm. The method includes determining a first ice mass on a first wind turbine of the wind farm; determining at least one second ice mass on at least one second wind turbine of the wind farm; comparing a first ice mass with a second ice mass and determining a primary wind turbine, which serves as a reference, and at least one secondary wind turbine from the group of the first wind turbine and the at least one second wind turbine; switching off the at least one secondary wind turbine on the basis of a first ice mass from the primary wind turbine; and switching on the at least one secondary wind turbine on the basis of a second ice mass from the primary wind turbine.

Abstract: a method of controlling a wind power installation comprising the steps: detecting a precipitation in the region of the wind power installation by a precipitation sensor, and controlling the wind power installation in a first operating mode based on a first pitch angle characteristic in which the pitch angle is set in dependence on the power, and in a second operating mode based on a second pitch angle characteristic, wherein the first operating mode is selected if there is no precipitation and the second operating mode is selected if there is precipitation.