The invention concerns a hydraulic turbine comprising blades (2) fixed to a runner crown (12) and to be actuated in rotation around an axis of rotation, each blade being comprised between a leading edge (8) and a trailing edge (10), a stationary head cover (14) and a chamber (16) being located between said runner crown (12) and said head cover (14) or within the head cover, said runner further comprising: means (22) forming at least one passage for water between said chamber and a chamber (28) in the runner tip; an upper portion (12.sub.1) and a lower portion (12.sub.2) of the said runner crown, said upper portion (12.sub.1) having a larger diameter than said lower portion (12.sub.2) so as to define a channel (24) between them, said channel leading to an exhaust volume (3) of the runner.

A centrifugal compressor includes: an upstream side squeeze portion having a flow passage cross-sectional area that decreases as the upstream side squeeze portion extends closer to a compressor impeller; a partition wall facing the inner circumferential surface of the upstream side squeeze portion and arranged with a gap from the inner circumferential surface of the upstream side squeeze portion; and a protrusion protruding from at least one of the inner circumferential surface of the upstream side squeeze portion or the outer circumferential surface of the partition wall.

The present invention provides an assembly platform of a large tidal current energy generating device. The assembly platform is internally provided with at least one horizontal axis hydro-generator. The assembly platform includes supports, at least four fixed piles, at least two sleeving members and at least two force-bearing supports. The fixed piles are connected through the supports to form an installation space. The hydro-generator is installed inside the installation space, one end of each fixed pile is driven to be fixed to a seabed and the other end extends to be above a water surface. Ends of the at least two force-bearing supports are respectively mounted on the left and right sides of the horizontal axis hydro-generator along the water flow direction and the other ends are respectively provided with corresponding sleeving members so as to resist an impact force of a water flow on the horizontal axis hydro-generator.

A hydraulic turbine includes a runner having a shaft, a runner crown, and a runner tip. Blades are fixed to the runner crown and are rotatable around an axis of rotation in operation of the hydraulic turbine, each blade including a leading edge and a trailing edge. A first chamber is located between the runner crown and a stationary head cover, or within head cover. A second chamber is located in the runner tip. A passage for water is defined between the first chamber and the second chamber. The runner crown has an upper portion and a lower portion, the upper portion having a larger diameter than the lower portion such that a channel is defined between the upper and lower portions. The channel has a circular shape and a circular symmetry around the axis of rotation and leads to a discharge region below the runner.

A hydraulic turbine includes a runner having a shaft, a runner crown, and a runner tip. Blades are fixed to the runner crown and are rotatable around an axis of rotation in operation of the hydraulic turbine, each blade including a leading edge and a trailing edge. A first chamber is located between the runner crown and a stationary head cover, or within head cover. A second chamber is located in the runner tip. A passage for water is defined between the first chamber and the second chamber. The runner crown has an upper portion and a lower portion, the upper portion having a larger diameter than the lower portion such that a channel is defined between the upper and lower portions. The channel has a circular shape and a circular symmetry around the axis of rotation and leads to a discharge region below the runner.

A hydroelectric power generation system includes: a generator driven by the hydraulic turbine; a head adjuster adjusting an effective head of the hydraulic turbine; and a controller cooperatively executing: flow rate control for controlling the generator such that a flow rate in the hydraulic turbine is brought close to a target flow rate; and head adjusting control for adjusting the effective head of the hydraulic turbine using the head adjuster such that the effective head of the hydraulic turbine falls within a first range.

The invention concerns a hydraulic turbine comprising a runner crown or a hub (1), possibly a band (2), and blades (3) fixed to said crown or hub, or between said band and said crown, and to be actuated in rotation around an axis of rotation, each blade comprising: a leading edge (8) and a trailing edge (10), at least one local extension (20) having a first contact surface fixed to the trailing edge of the blade (2), a second contact surface fixed to either said band (6) or said crown (4) and two lateral sides (24.sub.1, 24.sub.2) joining at a ridge line (22).

The invention concerns a hydraulic turbine comprising a runner crown or a hub (1), possibly a band (2), and blades (3) fixed to said crown or hub, or between said band and said crown, and to be actuated in rotation around an axis of rotation, each blade comprising: a leading edge (8) and a trailing edge (10), at least one local extension (20) having a first contact surface fixed to the trailing edge of the blade (2), a second contact surface fixed to either said band (6) or said crown (4) and two lateral sides (24.sub.1, 24.sub.2) joining at a ridge line (22).

The present invention relates to a cavitation free rotary mechanical device with improved output and, in particular, to a rotary mechanical device (such as a hydro turbine, marine propeller, etc) including a rotatable shaft and associated blades (or cups or vanes), the rotary mechanical device configured to introduce air at one or more areas of extremely low pressure force on the surface of, or at least in the proximity of, the rotatable blades (or cups or vanes) during rotation and thereby prevent cavitation effects that would otherwise be caused by the extremely low pressure forces acting on such surfaces during operation.

This document discloses a solution for analysing cavitation in a hydro turbine of a hydroelectric power plant. According to an aspect, a method comprises: measuring, by using at least one motion sensor coupled to a rotor of the hydro turbine, motion of the rotor during operation of the hydro turbine and thereby generating measurement data; acquiring, by at least one processor, the measurement data and one or more operational parameters of the hydro turbine employed during said measuring, the one or more operational parameters indicative of power supply of the hydro turbine; computing, by the at least one processor on the basis of the measurement data and the operational parameters, at least one metric indicative of an effect of the cavitation on the hydro turbine; comparing, by the at least one processor, the at least one metric with at least one threshold and determining, on the basis of the comparison, that the effect of the cavitation is too high; and outputting, by the at least one processor on the basis of said determining, information indicating unsuitability of the one or more operational parameters.