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.