A wind or tidal turbine blade having an attachment, the attachment including: a support portion of the turbine blade, the support portion having opposite surfaces; an insert adapted to mount a bolt for attaching the support portion to another structure; and a mounting for fitting the insert to the support portion, the mounting including a layer extending over a front face of the insert and bonded to the opposite surfaces of the support portion on opposite sides of the insert, the layer permitting passage of a bolt therethrough to or from the insert.

An assembly of rotor blades and hub for a turbine, such as a tidal current turbine. Each rotor blade includes a cavity and at least two ribs extending into the cavity at a radially inward (lower) region of the rotor blade. The hub includes a journal for each blade and the journal extends into the cavity and is supported by the at least two ribs.

A hydropower generator includes: a driving shaft installed along a path through which a fluid flows; a plurality of blade assemblies installed along a lengthwise direction of the driving shaft; a spinning supporter connected to rotatably support the driving shaft; a power generator receiving a spinning force of the driving shaft and generating electricity; and a flow pipeline internally provided with the driving shaft along a lengthwise direction thereof and formed with a channel through which a fluid flows.

A marine propeller has an outer hub having a central axis and a blade having a blade root attached to the outer hub and extending radially outward from the outer hub toward a blade tip. The blade has a leading edge and a trailing edge. The propeller has a diameter between about 15 inches and about 17 inches and a pitch between about 14 inches and about 24 inches. The blade has a progressive rake angle such that a first local rake angle at the blade root is less than a second local rake angle at the blade tip. A combination of the diameter, pitch, and progressive rake angle provides a marine vessel to which the marine propeller is coupled with minimum drag while the marine vessel is operating at less than a maximum vessel speed. A method of designing a propeller is also disclosed.

A rotor 16 is provided, including a vertical rotation axis 12 and at least two rotor blades 18, 20, 22 arranged on the rotation axis 12, wherein at least one rotor blade 18, 20, 22 includes an opening 60 with an openable closure element 62. Due to the design of the rotor blade 18, 20, 22, the rotor 16 has particularly high efficiency.

Embodiments of the present invention are related to a shrouded Kaplan and shrouded propeller-type hydraulic turbine. More in particular, the embodiments relate to a blade for such shrouded turbines. An object of the embodiments of the present invention is to add a winglet on the pressure side of a blade to eliminate a large gap between the blade and the shroud, in order to improve performances, decrease marginal cavitation, and improve fish friendliness.

The invention concerns an inter-blade profile (14) for a turbine runner blade, said inter-blade profile (14) comprising a profile (16), and a plug (18), forming a basis of the profile (16) and intended for being inserted into a corresponding hole (21) made in a blade.

A screw system including a plurality of segmented blades. Each blade segment of the plurality of blade segments including a mounting portion and a vane portion. The mounting portion, having a helical length, for removably attaching the blade segment. The vane portion extending from the mounting portion along the helical length thereof. The vane portion having a front surface that is not parallel to a back surface from the mounting portion to a tip of the blade segment, along the helical length.

A runner for a hydraulic turbine or pump includes a plurality of blades, each blade being defined by a pressure surface, an oppositely facing suction surface, a leading edge and a spaced apart trailing edge. At least one blade has a device for supplying a flow of oxygen containing gas to the trailing edge of at least one of the blades. The profile of the suction side surface of the blade along a cross section through a point P1 and a point P2 is concave. The point P1 is located on the suction side surface of the trailing edge where an opening is located, the point P2 is spaced apart from the point P1 by less than 3% of the runner outlet diameter D and the point P2 is located upstream of the point P1 on a line perpendicular to the trailing edge starting at the point P1.

According to the embodiment, in a range from a plane P1 including a runner rotation center axis C and an end point 15E2 of an outlet end 15 of the vane 13, up to a plane P2 corresponding to a position where the plane P1 is moved by an angle, which is determined by dividing 360° by a value that is four times the number of vanes 13, in a runner rotation direction, when respective sections of the vane 13 are taken at a plane including the axis C and radially extending, in at least one section, a tangent T1 on a centerline Cv of the vane 13 passing through an intersection X at which the centerline Cv and a flowing water surface 12f intersect, and a tangent T2 on the flowing water surface 12f passing through the intersection X, define an acute angle on a negative pressure surface.