A wind turbine blade includes a trailing edge flap having a flap part protruding from the trailing edge on the pressure side of the blade. The flap part has a first section and a second section each having an upstream surface arranged to face an oncoming airflow in use. The first section extends from the trailing edge and has a proximal end and a distal end in cross-section. The proximal end is located at or near the trailing edge and the distal end is spaced apart from the trailing edge. The first section is oriented such that an obtuse angle is defined between the upstream surface of the first section and a plane that extends parallel to the local chordal plane and intersects the proximal end of the first section. The second section is oriented such that the upstream surfaces of the first and second sections together define a concave profile in cross section.

A rotor blade uses hot-air, for example exhaust from a generator positioned inside a nacelle of a wind turbine, for de-icing and/or anti-icing. The rotor blade has an airfoil section and a cavity enclosed therein. A flow path inside the cavity, for flow of the hot-air, extends from a root section towards a tip section. Exhaust holes, fluidly connected with the flow path, at an outer surface of the airfoil section emit the hot-air from the airfoil section. The rotor blade includes a cover plate positioned at the outer surface of the airfoil section and masking the exhaust holes, thereby creating an external flow space between the exhaust holes and the cover plate's inner surface. The cover plate guides the hot-air over the outer surface of the airfoil section after the hot-air exits, via the exhaust holes, the airfoil section and before the hot-air escapes the rotor blade.

A wind turbine blade (10) is described having a serrated trailing edge (20). Splitter plates (106) are provided on the blade, to reduce operational noise. Each splitter plate (106) is arranged to extend at least partly into a space in between adjacent serrations. The splitter plates can be formed integrally with the serrations, or attached to existing serrations as a retrofit solution. The serrations with the splitter plates can be provided as a trailing edge panel (108) for attachment to the trailing edge of an existing wind turbine blade.

A rotor blade assembly for a wind turbine includes a rotor blade having surfaces defining a pressure side, a suction side, a leading edge, and a trailing edge extending between a blade tip and a blade root. The rotor blade assembly also includes at least one noise reducer adjacent to the trailing edge. The noise reducer(s) includes at least one serration extending beyond the trailing edge in a chord-wise direction of the rotor blade. The serration(s) also includes a suction side surface and a pressure side surface. The suction side surface defines a first radius of curvature in the chord-wise direction and the pressure side surface defines a second radius of curvature in the chord-wise direction. Further, the first radius of curvature may be larger than the second radius of curvature such that the suction side surface is flatter than the pressure side surface or vice versa.

A structure adapted to traverse a fluid environment includes an elongate body having a root, a wingtip, a leading edge and a trailing edge; and a plurality of rigid projections each extending from a respective position along the leading edge and/or the trailing edge generally along the same plane as a front surface of the body.

A serrated panel (70) for a wind turbine blade is disclosed. The panel (70) is configured to be attached to the trailing edge of a blade to form a plurality of serrations (71) at the trailing edge of the blade. The serrated panel comprises a base part (72) for attaching the panel (70) to the trailing edge of the blade. An exterior surface (78) of the base part comprises a corrugated surface in direction between longitudinal ends of the panel such that the exterior surface comprises crests (82) aligned substantially with midpoints of bases (80) of the serrations (71) and valleys (83) aligned substantially between serrations (71).

A fluid-redirecting structure includes a rigid body having an upstream end, a downstream end, and an axis of rotation, the rigid body incorporating a plurality of troughs each spiralled from a tip at the upstream end to the downstream end about the axis of rotation, the troughs being splayed with respect to the axis of rotation thereby to, proximate the downstream end, direct incident fluid along the troughs away from the axis of rotation.

A serrated panel (70) for a wind turbine blade is disclosed. The panel (70) is configured to be attached to the trailing edge of a blade to form a plurality of serrations (71) at the trailing edge of the blade. The serrated panel comprises a base part (72) for attaching the panel (70) to the trailing edge of the blade. An exterior surface (78) of the base part comprises a corrugated surface in direction between longitudinal ends of the panel such that the exterior surface comprises crests (82) aligned substantially with midpoints of bases (80) of the serrations (71) and valleys (83) aligned substantially between serrations (71).

A rotor blade assembly for a wind turbine includes a rotor blade having surfaces defining a pressure side, a suction side, a leading edge, and a trailing edge extending between a blade tip and a blade root. The rotor blade assembly also includes at least one noise reducer adjacent to the trailing edge. The noise reducer(s) includes at least one serration extending beyond the trailing edge in a chord-wise direction of the rotor blade. The serration(s) also includes a suction side surface and a pressure side surface. The suction side surface defines a first radius of curvature in the chord-wise direction and the pressure side surface defines a second radius of curvature in the chord-wise direction. Further, the first radius of curvature may be larger than the second radius of curvature such that the suction side surface is flatter than the pressure side surface or vice versa.

A fluid-redirecting structure includes a rigid body having an upstream end, a downstream end, and an axis of rotation, the rigid body incorporating a plurality of troughs each spiralled from a tip at the upstream end to the downstream end about the axis of rotation, the troughs being splayed with respect to the axis of rotation thereby to, proximate the downstream end, direct incident fluid along the troughs away from the axis of rotation.