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 blade for a wind turbine can include an elongated and curved sheet having a curved root, a curved tip, a leading edge, and a trailing edge. The root and the tip can be rotated relative to each other such that the blade is twisted along its length. The root can include an edge having curved projections, the curved projections being distributed along a curvature of the root. A wind turbine can include a mounting element and a plurality of turbine blades. Each turbine blade can be attached to the mounting element closer to the trailing edge than to the leading edge such that an intersection of the leading edge and the root projects upstream from the wind turbine. A wind turbine generator assembly for converting wind into electrical energy can include a wind turbine and a generator. In addition, a support structure can support the wind turbine and generator.

A blade for a wind turbine can include an elongated and curved sheet having a curved root, a curved tip, a leading edge, and a trailing edge. The root and the tip can be rotated relative to each other such that the blade is twisted along its length. The root can include an edge having curved projections, the curved projections being distributed along a curvature of the root. A wind turbine can include a mounting element and a plurality of turbine blades. Each turbine blade can be attached to the mounting element closer to the trailing edge than to the leading edge such that an intersection of the leading edge and the root projects upstream from the wind turbine. A wind turbine generator assembly for converting wind into electrical energy can include a wind turbine and a generator. In addition, a support structure can support the wind turbine and generator.

A wind turbine blade with a flow guiding device attached to a profiled contour on a pressure side of the blade is described. The flow guiding device has a front surface facing toward an oncoming airflow and comprises at least a first portion, which is angled towards the oncoming airflow and a leading edge of the wind turbine blade.

The present invention relates to a wind turbine blade (10) comprising a shell body with at least one pressure side shell member (36) and at least one suction side shell member (38), and a plurality of shear webs (70) arranged within the shell body. The plurality of shear webs (70) is successively arranged spanwise within the shell body such that adjacent shear webs overlap along part of their spanwise extent (L), wherein a gap (88) in the chordwise direction is provided between adjacent shear webs (70).

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.

A heat dissipation fan including a hub and a plurality of heat dissipation blades is provided. The heat dissipation blades are arranged around the periphery of the hub. Each of the heat dissipation blades includes a curved surface body and a flow guiding portion. The curved surface body has a pressure bearing surface and a negative pressing surface opposite to the pressure bearing surface. The flow guiding portion is connected to the curved surface body. The flow guiding portion has a concave surface and a convex surface opposite to the concave surface, wherein the concave surface is recessed in the pressure bearing surface and the convex surface protrudes outward from the negative pressing surface.

A drag-based wind turbine device is disclosed. The device is an improved wind turbine comprised of two sets of stacked and coupled, drag-based vertical axis wind turbines, wherein drag from the first turbine helps propel the second turbine. Additionally, the surface of the first turbine is convex to ensure wind is always deflected toward the second turbine, wherein the wind is then received by the concave side of the second turbine. Further, the blades are arranged in a horizontal and sloping manner. In the convex position, each slope blade deflects incoming wind to the other set of turbines in a concave direction. Additionally, the gap between two turbines can be adjusted for different wind/current speeds, viscosities, compressibility, and densities for the best efficiency.

Provided is a blade capable of efficiently utilizing low-velocity fluid. The blade includes a main wing component, the main wing component has a streamlined cross section, an outer profile of which forms a first airfoil, the blade further includes a head wing piece in form of a sheet, the head wing piece has an arc-shaped cross section with a convex surface at one side and a concave surface at the other side, the head wing piece is arranged obliquely above a leading-edge point of the main wing component with the concave surface of the head wing piece facing the main wing component and a first ventilation space is formed between the head wing piece and the main wing component. By improving the configuration of the wing pieces of the blade, Cp of the blade is improved, and the manufacture cost of the blade can be significantly reduced.

A blade for a wind turbine can include an elongated and curved sheet having a root, a tip positioned opposite the root, a leading edge spanning between the root and the tip along a length of the blade, and a trailing edge spanning between the root and the tip opposite the leading edge. The blade can include a generally concave surface formed by curvature of the blade about a longitudinal axis. The blade can further include one or more air dams, which can be in the form of strip elements oriented transverse to the longitudinal axis and extending away from the concave surface. The air dams improve torque and efficiency of the blade. In some embodiments, an edge of the root can include a plurality of curved projections distributed thereon. A wind turbine system can include a generator and a wind turbine having a mounting element to support turbine blades.