Abstract: A tip structure may be arranged for example on a rotor blade (12) of a HAWT (10). The tip structure comprises a pressure side structure (50) arranged on a pressure side (43) of the blade, and a suction side structure (60) arranged on a suction side (44) of the blade (12). The pressure side and suction side structures (50, 60) have different pitch angles (?P, ?S) so that the chord (CP2) of the pressure side structure (50) extends forwardly in the direction of motion (D) and relatively more radially outwardly away from the blade root, or less radially inwardly towards the blade root, than the chord (CS2) of the suction side structure (60), defining a relative twist angle (?T) between the two structures (50, 60).

Abstract: A tip structure may be arranged for example on a rotor blade (12) of a HAWT (10). The tip structure comprises a pressure side structure (50) arranged on a pressure side (43) of the blade, and a suction side structure (60) arranged on a suction side (44) of the blade (12). The pressure side and suction side structures (50, 60) have different pitch angles (?P, ?S) so that the chord (CP2) of the pressure side structure (50) extends forwardly in the direction of motion (D) and relatively more radially outwardly away from the blade root, or less radially inwardly towards the blade root, than the chord (CS2) of the suction side structure (60), defining a relative twist angle (?T) between the two structures (50, 60).

Abstract: Diffuser-augmented wind turbines can include a first diffuser ring arranged to form a turbine rotor cowling, the diffuser being fixed to and rotatable with the turbine rotor about the horizontal axis of the wind turbine. The first diffuser ring may have one or more dynamic, aero-elastic, vortex entrainment devices attached to a trailing edge of the diffuser. The first diffuser ring may include one or more slot gaps arranged within its body, each slot gap creating a channel between the interior and exterior surfaces of the first diffuser ring. In some embodiments the diffuser may optionally further include one or more further diffuser rings, the one or more further diffuser rings being static rings (e.g. non-rotatable about the horizontal axis) or dynamic diffuser rings (e.g. rotatable around the horizontal axis).

Abstract: An example wind turbine diffuser has an expanded outlet area where the diffuser outlet area is greater than it's cross sectional area. The diffuser may be formed of one or more diffuser rings, at least one of which may form a turbine cowling. Each diffuser ring may have an inlet area that is smaller than the outlet area of the directly upstream ring. The portion of an upstream ring outlet which is not occluded by the downstream ring may form a diffuser outlet such that the total outlet area of the diffuser is larger than the cross-sectional area. In another example, the diffuser may comprise at least one diffuser ring and one or more suction slots that are each connected to a vent, which allows air to be removed from the diffuser system.

Abstract: An example wind turbine diffuser has an expanded outlet area where the diffuser outlet area is greater than it's cross sectional area. The diffuser may be formed of one or more diffuser rings, at least one of which may form a turbine cowling. Each diffuser ring may have an inlet area that is smaller than the outlet area of the directly upstream ring. The portion of an upstream ring outlet which is not occluded by the downstream ring may form a diffuser outlet such that the total outlet area of the diffuser is larger than the cross-sectional area. In another example, the diffuser may comprise at least one diffuser ring and one or more suction slots that are each connected to a vent, which allows air to be removed from the diffuser system.

Abstract: Diffuser-augmented wind turbines can include a first diffuser ring arranged to form a turbine rotor cowling, the diffuser being fixed to and rotatable with the turbine rotor about the horizontal axis of the wind turbine. The first diffuser ring may have one or more dynamic, aero-elastic, vortex entrainment devices attached to a trailing edge of the diffuser. The first diffuser ring may include one or more slot gaps arranged within its body, each slot gap creating a channel between the interior and exterior surfaces of the first diffuser ring. In some embodiments the diffuser may optionally further include one or more further diffuser rings, the one or more further diffuser rings being static rings (e.g. non-rotatable about the horizontal axis) or dynamic diffuser rings (e.g.