A wind energy device (10) comprising a plurality of curved blades (14) mounted for rotation about a vertical rotational axis (13). Each of the blades (14) includes a linear inner edge (16), an outer edge (17) and upper and lower edges (18 and 19). The inner edges (16) of each of the blades (14) are located adjacent and parallel to the rotational axis (13) and the upper and lower edges (18, 19) are tapered from adjacent the inner edge (16) such that outer edges (19) of the blades (14) are shorter than the inner edges (16).

A structural tower for a wind turbine assembly, includes along at least a base section: a plurality of peripheral sections extending peripherally of a central section. Each includes a convex-shaped wall having two longitudinal side edges and an inner framework connected to a respective one of the convex-shaped walls and extending inwardly therein. The inner framework includes spaced-apart transversal structural members connecting the two longitudinal side edges of the convex-shaped walls together and pairs of connecting structural members extending inwardly towards the central section. Each connecting structural member of a pair has a peripheral end connected to a respective one of the longitudinal side edges and an inner end connected to an inner end of a respective one of the connecting structural members of an adjacent one of the peripheral sections to define a structural concavity in the structural tower between adjacent peripheral sections.

A vortex generator for a wind turbine blade to be mounted to a wind turbine blade includes: a platform portion to be mounted to a surface of the wind turbine blade; and at least one fin disposed upright on the platform portion. The platform portion has a cross section having a curved convex shape, at least along a blade spanwise direction of the wind turbine blade.

Rotor blade assemblies for wind turbines are provided. A rotor blade assembly includes a rotor blade. In some embodiments, the rotor blade assembly further includes a surface feature configured on an exterior surface of the rotor blade, the surface feature having an exterior mounting surface. At least a portion of the exterior mounting surface has a contour in an uninstalled state that is different from a curvature of the exterior surface of the rotor blade at a mount location of the surface feature on the rotor blade. In other embodiments, the rotor blade assembly further includes a seal member surrounding at least a portion of a perimeter of the surface feature. The seal member contacts and provides a transition between the exterior surface and the surface feature.

A structural tower for a wind turbine assembly, includes along at least a base section: a plurality of peripheral sections extending peripherally of a central section. Each includes a convex-shaped wall having two longitudinal side edges and an inner framework connected to a respective one of the convex-shaped walls and extending inwardly therein. The inner framework includes spaced-apart transversal structural members connecting the two longitudinal side edges of the convex-shaped walls together and pairs of connecting structural members extending inwardly towards the central section. Each connecting structural member of a pair has a peripheral end connected to a respective one of the longitudinal side edges and an inner end connected to an inner end of a respective one of the connecting structural members of an adjacent one of the peripheral sections to define a structural concavity in the structural tower between adjacent peripheral sections.

A hydrokinetic energy conversion system (1) comprising a turbine device (2) comprising a rotor (3) displaying a rotational axis (O), which turbine device is arranged to operate with the rotational axis in an inclined orientation vis--vis an incoming body of water (W), and which rotor comprises a blade (10) which is arranged to interact with the incoming body of water such that rotational energy is imparted to the rotor. The blade comprises a first, convex surface (12), a second, concave surface (13) and a free, distal edge (E) where the first surface and the second surface meet. The curvature of the second surface, when viewed in a plane orthogonal to the rotational axis, is such that a maximum depth (Dmax) of the second surface, when measured from a straight line intersecting the rotational axis and the distal edge, is at least 35% of the distance between the rotational axis and the distal edge.

A structural tower for a wind turbine assembly, includes along at least a base section: a plurality of peripheral sections extending peripherally of a central section. Each includes a convex-shaped wall having two longitudinal side edges and an inner framework connected to a respective one of the convex-shaped walls and extending inwardly therein. The inner framework includes spaced-apart transversal structural members connecting the two longitudinal side edges of the convex-shaped walls together and pairs of connecting structural members extending inwardly towards the central section. Each connecting structural member of a pair has a peripheral end connected to a respective one of the longitudinal side edges and an inner end connected to an inner end of a respective one of the connecting structural members of an adjacent one of the peripheral sections to define a structural concavity in the structural tower between adjacent peripheral sections.

Fan for ovens for cooking foods, which comprises: a support plate arranged substantially orthogonal to the rotation axis of the fan; and multiple blades projectingly fixed on the support plate and radially arranged around the rotation axis. Each blade of the fan is provided with an internal edge, which is shaped with a convex portion that is projectingly extended between a first and a second concavity of the internal edge itself.

Rotor blade assemblies for wind turbines are provided. A rotor blade assembly includes a rotor blade. In some embodiments, the rotor blade assembly further includes a surface feature configured on an exterior surface of the rotor blade, the surface feature having an exterior mounting surface. At least a portion of the exterior mounting surface has a contour in an uninstalled state that is different from a curvature of the exterior surface of the rotor blade at a mount location of the surface feature on the rotor blade. In other embodiments, the rotor blade assembly further includes a seal member surrounding at least a portion of a perimeter of the surface feature. The seal member contacts and provides a transition between the exterior surface and the surface feature.

A centrifugal compressor impeller includes a plurality of blades on a front side that extend from a first axial side to an outer radial end of the impeller. The centrifugal impeller includes a back side having a nonlinear backwall. The backwall can include a flat area hear a bore of impeller, a flat area near a tip of the impeller, and a convex surface between the flat areas of the bore and the tip. In some forms the impeller further includes a concave surface between the convex surface and the tip to form an s-shape. A transition or inflection point can denote the change from convex to concave. The convex and/or concave surfaces can take any variety of forms such as constant radius sections and/or compound curves.