Abstract: The present disclosure is directed to systems and methods for validating wind farm performance improvements so as to optimize wind farm performance. In one embodiment, the method includes operating, via a controller, the wind farm in a first operating mode. Another step includes collecting a first set of operating data, via a processor, during the first operating mode. A further step includes operating, via the controller, the wind farm in a second operating mode. The method also includes collecting a second set of operating data, via the processor, during the second operating mode. Next, the method includes normalizing the first and second sets of operating data based on wind speed distributions. As such, another step includes comparing, via the processor, the normalized first and second sets of operating data so as to validate one or more wind farm performance measurements.

Abstract: Vortex generators for wind turbine rotor blades having noise-reducing features are mounted within a laminar flow region on either the pressure side or the suction side of the rotor blade and have a base portion with at least one airflow modifying element extending therefrom. The base portion has a leading edge and a trailing edge extending in a first direction. Further, the base portion includes one or more edge features formed within either or both of the leading or trailing edges. Moreover, the edge features are non-parallel with respect to the first direction so as to reduce laminar boundary layer instability noise.

Abstract: The present disclosure is directed to vortex generators for wind turbine rotor blades having noise-reducing features. For example, the vortex generators are mounted within a laminar flow region on either the pressure side or the suction side of the rotor blade and have a base portion with at least one airflow modifying element extending therefrom. The base portion has a leading edge and a trailing edge extending in a first direction. Further, the base portion includes one or more edge features formed within either or both of the leading or trailing edges. Moreover, the edge features are non-parallel with respect to the first direction so as to reduce laminar boundary layer instability noise.

Abstract: Methods for producing ultrasonic sound emissions from wind turbines, active systems for emitting ultrasonic sounds from wind turbines, and wind turbines are provided. In one embodiment, a method includes operating the wind turbine with an ultrasonic sound emitting device mounted on or within a component of the wind turbine, and receiving in a controller at least one indicator. The method further includes determining if an operating condition exists based on the at least one indicator, and supplying a fluid flow through an outlet of the ultrasonic sound emitting device such that an ultrasonic sound emission is produced by the ultrasonic sound emitting device if the operating condition exists.

Abstract: Rotor blade assemblies and methods for constructing rotor blade assemblies are provided. A rotor blade assembly may include a rotor blade having exterior surfaces defining a pressure side, a suction side, a leading edge and a trailing edge each extending between a tip and a root, the rotor blade defining a span and a chord. The rotor blade assembly further includes an extension plate mounted to one of the pressure side or the suction side, the extension plate extending in the chord-wise direction between a first end and a second end, the second end extending beyond the trailing edge. The rotor blade assembly further includes a filler substrate provided on an inner surface of the extension plate and the trailing edge, the filler substrate tapering from the trailing edge towards the second end.

Abstract: The present disclosure is directed to systems and methods for validating wind farm performance improvements so as to optimize wind farm performance. In one embodiment, the method includes operating, via a controller, the wind farm in a first operating mode. Another step includes collecting a first set of operating data, via a processor, during the first operating mode. A further step includes operating, via the controller, the wind farm in a second operating mode. The method also includes collecting a second set of operating data, via the processor, during the second operating mode. Next, the method includes normalizing the first and second sets of operating data based on wind speed distributions. As such, another step includes comparing, via the processor, the normalized first and second sets of operating data so as to validate one or more wind farm performance measurements.

Abstract: An aerodynamic hub assembly for a wind turbine is disclosed. The hub assembly may include a hub extension, a rotor blade having a blade root and a blade tip, and a hub airfoil section mounted at least partially over the hub extension. The hub airfoil section may be fixed relative to the rotor blade or may be configured to rotate about a common pitch axis with the rotor blade. The hub extension may be connected to and extend radially from a center of the hub assembly. Further, the hub assembly may include a pitch bearing having an inner race and an outer race, wherein the pitch bearing may be coupled between the hub extension and the blade root. Additionally, the hub assembly may also include an aerodynamically-shaped spinner, wherein the spinner may house at least a portion of a root structure extending radially from the center of the hub assembly.

Abstract: A wind turbine may include a tower, a nacelle mounted on the tower and a rotor coupled to the nacelle. The rotor may include a hub and at least one rotor blade extending from the hub. In addition, the wind turbine may include a nozzle mounted on or within the tower, the nacelle or the hub. The nozzle may include an inlet and an outlet. Moreover, the nozzle may be configured to accelerate a flow of fluid through the outlet such that an ultrasonic sound emission is produced by the nozzle.

Abstract: A rotor blade for a wind turbine is disclosed. The rotor blade may generally include a body extending between a blade root and a blade tip. The body may include a pressure side and a suction side extending between a leading edge and a trailing edge. In addition, the rotor blade may include a nozzle mounted on or within the body. The nozzle may include an inlet, an outlet and a converging section between the inlet and the outlet. The converging section may be configured to accelerate a flow of air through the nozzle such that an ultrasonic sound emission is produced.

Abstract: Rotor blade assemblies and methods for constructing rotor blade assemblies are provided. A rotor blade assembly may include a rotor blade having exterior surfaces defining a pressure side, a suction side, a leading edge and a trailing edge each extending between a tip and a root, the rotor blade defining a span and a chord. The rotor blade assembly further includes an extension plate mounted to one of the pressure side or the suction side, the extension plate extending in the chord-wise direction between a first end and a second end, the second end extending beyond the trailing edge. The rotor blade assembly further includes a filler substrate provided on an inner surface of the extension plate and the trailing edge, the filler substrate tapering from the trailing edge towards the second end.

Abstract: An aerodynamic hub assembly for a wind turbine is disclosed. The hub assembly may include a hub extension, a rotor blade having a blade root and a blade tip, and a hub airfoil section mounted at least partially over the hub extension. The hub airfoil section may be fixed relative to the rotor blade or may be configured to rotate about a common pitch axis with the rotor blade. The hub extension may be connected to and extend radially from a center of the hub assembly. Further, the hub assembly may include a pitch bearing having an inner race and an outer race, wherein the pitch bearing may be coupled between the hub extension and the blade root. Additionally, the hub assembly may also include an aerodynamically-shaped spinner, wherein the spinner may house at least a portion of a root structure extending radially from the center of the hub assembly.

Abstract: Methods for producing ultrasonic sound emissions from wind turbines, active systems for emitting ultrasonic sounds from wind turbines, and wind turbines are provided. In one embodiment, a method includes operating the wind turbine with an ultrasonic sound emitting device mounted on or within a component of the wind turbine, and receiving in a controller at least one indicator. The method further includes determining if an operating condition exists based on the at least one indicator, and supplying a fluid flow through an outlet of the ultrasonic sound emitting device such that an ultrasonic sound emission is produced by the ultrasonic sound emitting device if the operating condition exists.

Abstract: A wind turbine may include a tower, a nacelle mounted on the tower and a rotor coupled to the nacelle. The rotor may include a hub and at least one rotor blade extending from the hub. In addition, the wind turbine may include a nozzle mounted on or within the tower, the nacelle or the hub. The nozzle may include an inlet and an outlet. Moreover, the nozzle may be configured to accelerate a flow of fluid through the outlet such that an ultrasonic sound emission is produced by the nozzle.

Abstract: A rotor blade assembly for a wind turbine is disclosed. The rotor blade assembly includes a rotor blade having surfaces defining a pressure side, a suction side, a leading edge, and a trailing edge extending between a tip and a root. The rotor blade further includes a noise reducer configured on a surface of the rotor blade, the noise reducer comprising a plurality of serrations, each of the plurality of serrations defining a centerline. The centerline of each of the plurality of serrations defines a individual tailored angle dependent on at least one of span-wise location, local chord, width, length, bend angle, and thickness.

Abstract: A rotor blade for a wind turbine is disclosed. The rotor blade may generally include a body extending between a blade root and a blade tip. The body may include a pressure side and a suction side extending between a leading edge and a trailing edge. In addition, the rotor blade may include a nozzle mounted on or within the body. The nozzle may include an inlet, an outlet and a converging section between the inlet and the outlet. The converging section may be configured to accelerate a flow of air through the nozzle such that an ultrasonic sound emission is produced.

Abstract: A shroud for a wind turbine and a method for modifying performance of a wind turbine are disclosed. The wind turbine includes a rotor mounted to a nacelle, the rotor including a plurality of rotor blades and defining an outer diameter. The shroud is positioned downstream of the rotor in an air flow direction, and has an inner diameter of less than the outer diameter of the rotor.

Abstract: In one aspect, a method for controlling the amplitude modulation of the noise generated by wind turbines is generally disclosed. The method may include determining a sound characteristic of a turbine sound wave generated by a wind turbine and generating an additive sound wave based on the sound characteristic such that a resultant sound wave is produced having a peak-to-peak amplitude that is smaller than a peak-to-peak amplitude of the turbine sound wave.

Abstract: A rotor blade assembly for a wind turbine is disclosed. The rotor blade assembly includes a rotor blade having surfaces defining a pressure side, a suction side, a leading edge, and a trailing edge extending between a tip and a root. The rotor blade assembly further includes a noise reducer configured on a surface of the rotor blade. The noise reducer includes a plurality of noise reduction features and a plurality of auxiliary noise reduction features. Each of the plurality of auxiliary noise reduction features is configured on one of the plurality of noise reduction features.

Abstract: In one aspect, a method for controlling the amplitude modulation of noise generated by a wind turbine is disclosed. The method may generally include determining an angle of attack of a rotor blade of a wind turbine and maintaining the angle of attack at a substantially constant value during rotation of the rotor blade in order to reduce the amplitude modulation of the noise generated by the wind turbine.

Abstract: In one aspect, a method for controlling the amplitude modulation of the noise generated by wind turbines is disclosed. The method may include determining a rotor position of a first wind turbine, determining a rotor position of a second wind turbine, determining if the first and second wind turbines are operating in-phase and, in the event that the first and second wind turbines are operating in-phase, adjusting an operating condition of at least one of the first wind turbine and the second wind turbine so that the first and second wind turbines operate out-of-phase.