Abstract: A wind turbine blade airfoil trailing edge (TE) with a first waveform profile (44B, 44C, 44E) as seen from behind, formed by ruffles or alternating ridges (21) and valleys (22) formed on the airfoil (20) and ending at the trailing edge. The trailing edge may further include a second waveform profile (48B, 48C, 48E) as seen from above, resulting from serrations formed by an oblique termination plane (32B) of the trailing edge or by other geometry. The ridges and/or serrations may be asymmetric (44E, 48E) to increase a stall fence effect of the ridges on the suction side (SS) of the trailing edge. The first and second waveforms may have the same period (44B, 48B) or different periods (44C, 48C).

Abstract: A wind turbine blade (80, 82) having a spanwise series of vortex generators (26, 28, 26P, 28P, 64, 66) and having a trailing edge (42) defining a waveform. The vortex generators are aligned with a predetermined position or phase (44, 46) of a respective period of the trailing edge waveform. Each vortex generator may be designed to create a vortex (27, 29) that crosses the trailing edge at an angle of less than 30 degrees from parallel to the trailing edge. The blade may include alternating ridges (52) and troughs (54) that end at the waveform trailing edge. A front end of each trough may form a V-shaped drop-off in the suction side of the blade that forms a pair (64, 66) of vortex generators to create counter-rotating vortices within the trough that entrain energy to the bottom of the trough.

Abstract: A slat (30) extending along an inboard portion of a wind turbine main blade element (22). The slat may have an end vortex modification appendage, such as winglet (34), endplate (64), raked wingtip (70), or down turned wingtip (72), and may be located behind a line defined perpendicular to a mean camber line of the main blade element at a leading edge of the main blade element. At least the leading edge (42S) of the slat may be disposed within a zone (48) of airflow that generally parallels the suction side (40) of the main blade element. The slat may have a flatback trailing edge (44F). Vortex generators (60) may be attached to the slat. Slats may be retrofitted to a wind turbine rotor (20) by attaching them to the spar caps (56) of the blades or to the hub (26) of the rotor.

Abstract: A wind turbine blade (80, 82) having a spanwise series of vortex generators (26, 28, 26P, 28P, 64, 66) and having a trailing edge (42) defining a waveform. The vortex generators are aligned with a predetermined position or phase (44, 46) of a respective period of the trailing edge waveform. Each vortex generator may be designed to create a vortex (27, 29) that crosses the trailing edge at an angle of less than 30 degrees from parallel to the trailing edge.

Abstract: A wind turbine blade airfoil trailing edge (TE) with a first waveform profile (44B, 44C, 44E) as seen from behind, formed by ruffles or alternating ridges (21) and valleys (22) formed on the airfoil (20) and ending at the trailing edge. The trailing edge may further include a second waveform profile (48B, 48C, 48E) as seen from above, resulting from serrations formed by an oblique termination plane (32B) of the trailing edge or by other geometry. The ridges and/or serrations may be asymmetric (44E, 48E) to increase a stall fence effect of the ridges on the suction side (SS) of the trailing edge. The first and second waveforms may have the same period (44B, 48B) or different periods (44C, 48C).

Abstract: A rotor blade of a wind turbine with a raked tip portion is provided. The tip portion is raked, i.e. curved, in a rotor blade plane comprising the tip base chord and a line which is parallel to the pitch axis of the rotor blade. Additionally, the orientation of the chords with reference to the chord at the tip base changes between the tip base and the tip. In other words, the trailing edge of the tip portion is twisted. Optionally, the tip portion is additionally swept out of the rotor blade plane, which is characterized by a cant angle.

Abstract: A ridge (28) mounted or defined along a trailing edge (22) of an airfoil (20) for noise reduction. Sides (32, 34) of the ridge converge from respective suction and pressure sides (46, 48) of the trailing edge to a peak (30) of the ridge pointing aft. The sides of the ridge may be concave. The ridge may be hollow (42) or have a core (43) of a sound-absorbing material. The sides of the ridge may be perforated (44A, 44B) for pressure equalization across the ridge. The ridge may be covered with bristles (56) or be defined by the tips (58) of bristles (56A, 56B) of varying length. The peak of the ridge and/or at least one corner (64, 66) of the ridge and/or of the trailing edge (46, 48) may be serrated.

Abstract: A vortex generating foil (26A-G) extending from an aerodynamic surface (22) of a wind turbine blade (20), the foil having a nest shape (43A, 43F-G) along a suction side (32A-G) of the foil effective to reduce flow separation between the foil and a leading edge vortex (27, 29) formed in a flow passing over the foil. The nest shape may be formed in part by a progressive fillet (42) between the suction side of the foil and the suction side of the wind turbine blade. The nest shape may be formed in part by a distal portion (40C-D) of the foil curling over the suction side of the foil. A trailing edge fillet (52E-G) may form a ridge (54E-G), which may extend the nest shape aft of the trailing edge of the foil. A nest shape axis (50E-G) may diverge from an incidence angle (?) of the foil.

Abstract: A slat (30) extending along an inboard portion of a wind turbine main blade element (22). The slat may have an end vortex modification appendage, such as winglet (34), endplate (64), raked wingtip (70), or down turned wingtip (72), and may be located behind a line defined perpendicular to a mean camber line of the main blade element at a leading edge of the main blade element. At least the leading edge (42S) of the slat may be disposed within a zone (48) of airflow that generally parallels the suction side (40) of the main blade element. The slat may have a flatback trailing edge (44F). Vortex generators (60) may be attached to the slat. Slats may be retrofitted to a wind turbine rotor (20) by attaching them to the spar caps (56) of the blades or to the hub (26) of the rotor.