Abstract: A hydraulic turbine includes a rotor with a runner, which is concentrically surrounded by a stator, whereby the runner comprises a plurality of runner blades arranged and distributed in a ring around a rotor axis, and each runner blade extends between a runner crown and a runner band; whereby the stator comprises a plurality of guide vanes arranged and distributed in a ring around the rotor axis, and each guide vane extends between an upper stator ring and a lower stator ring; and whereby a predetermined clearance is provided at least between the runner band and the lower stator ring. A substantial reduction of pressure pulsations in the vane-less gap between said runner blades of said runner is achieved by substantially increasing said predetermined clearance.

Abstract: A hydraulic turbine includes a rotor with a runner, which is concentrically surrounded by a stator, whereby the runner comprises a plurality of runner blades arranged and distributed in a ring around a rotor axis, and each runner blade extends between a runner crown and a runner band; whereby the stator comprises a plurality of guide vanes arranged and distributed in a ring around the rotor axis, and each guide vane extends between an upper stator ring and a lower stator ring; and whereby a predetermined clearance is provided at least between the runner band and the lower stator ring. A substantial reduction of pressure pulsations in the vane-less gap between said runner blades of said runner is achieved by substantially increasing said predetermined clearance.

Abstract: A hydraulic turbine includes a rotor with a runner, which is concentrically surrounded by a stator, whereby the runner comprises a plurality of runner blades arranged and distributed in a ring around a rotor axis, and each runner blade extends between a runner crown and a runner band; whereby the stator comprises a plurality of guide vanes arranged and distributed in a ring around the rotor axis, and each guide vane extends between an upper stator ring and a lower stator ring; and whereby a predetermined clearance is provided at least between the runner band and the lower stator ring. A substantial reduction of pressure pulsations in the vane-less gap between said runner blades of said runner is achieved by substantially increasing said predetermined clearance.

Abstract: This method can be used for refurbishing a facility for converting hydraulic energy into electrical or mechanical energy, and vice versa. The facility includes a Francis type pump-turbine. The pump-turbine includes a runner movable about an axis, a pre-distributor, including stay vanes defining between each pair of two adjacent stay vanes a first water passage channel and a distributor, including guide vanes arranged downstream of the stay vanes in the direction of water flow feeding the pump-turbine operating in turbine mode. The guide vanes define between each pair of two adjacent guide vanes a second water passage channel. This method includes steps of reducing the height, taken parallel to the axis of rotation of the runner, of the first water passage channels and reducing the height, taken parallel to the axis of rotation of the runner, of the second water passage channels.

Abstract: A hydraulic turbine includes a rotor with a runner, which is concentrically surrounded by a stator, whereby the runner comprises a plurality of runner blades arranged and distributed in a ring around a rotor axis, and each runner blade extends between a runner crown and a runner band; whereby the stator comprises a plurality of guide vanes arranged and distributed in a ring around the rotor axis, and each guide vane extends between an upper stator ring and a lower stator ring; and whereby a predetermined clearance is provided at least between the runner band and the lower stator ring. A substantial reduction of pressure pulsations in the vane-less gap between said runner blades of said runner is achieved by substantially increasing said predetermined clearance.

Abstract: The invention relates to a Francis runner (200) for a hydraulic machine, comprising: a wheel (1), which is rotationally symmetrical about an axis of rotation (Z) of the runner (200); a crown (12); and a plurality of inwardly curved vanes (21), each of which has a peripheral edge (212). The peripheral edge (212) of at least one of the vanes is curved, the concavity thereof facing toward the outside of the runner (200). The maximum value of the distance measured between any point on the peripheral edge (202) and a straight line passing through a first connection point between the peripheral edge (212) and the wheel (1), and through a second connection point between the peripheral edge (212) and the crown (12), is at an intermediate point on the peripheral edge (212). The radius (Rn) from the intermediate point (N) is strictly smaller than the radius (Ra) from the first connection point (A).

Abstract: This method can be used for refurbishing a facility for converting hydraulic energy into electrical or mechanical energy, and vice versa. The facility includes a Francis type pump-turbine. The pump-turbine includes a runner movable about an axis, a pre-distributor, including stay vanes defining between each pair of two adjacent stay vanes a first water passage channel and a distributor, including guide vanes arranged downstream of the stay vanes in the direction of water flow feeding the pump-turbine operating in turbine mode. The guide vanes define between each pair of two adjacent guide vanes a second water passage channel. This method includes steps of reducing the height, taken parallel to the axis of rotation of the runner, of the first water passage channels and reducing the height, taken parallel to the axis of rotation of the runner, of the second water passage channels.

Abstract: This wheel comprises a plurality of vanes (2) arranged on a crown (3) and is equipped with a tip-forming member (10) attached to a central region (32) of the crown or hub of the wheel (1), radially inside the vanes (2), the crown defining a wet surface (31) for guiding a flow (E) passing between the vanes. The tip-forming member (10) is provided with at least one opening (121) for diverting a fraction (E1) of the flow towards the internal volume (V10) of this member. This member comprises a frustoconical annular skirt (11) and at least one fin (15) arranged in its internal volume (V10) and able to modify the path of the flow fraction (E1) entering this volume through the opening (121). This fin (15) extends as far as the edge (112) of the skirt (11) which defines an outlet opening (14) of the member (10) for the flow fraction (E1).

Abstract: This member (4) can be attached to the crown (12) of a wheel (1) of a hydraulic machine. It is provided with a skin (42) of which a surface (421) is able to be arranged in the continuation of a wet surface (121) of the crown. This member is equipped with at least one fun (43) arranged radially inside the skirt (42) and projecting axially (h) from the skirt (42) in the downward direction.

Abstract: The invention relates to a Francis runner (200) for a hydraulic machine, comprising: a wheel (1), which is rotationally symmetrical about an axis of rotation (Z) of the runner (200); a crown (12); and a plurality of inwardly curved vanes (21), each of which has a peripheral edge (212). The peripheral edge (212) of at least one of the vanes is curved, the concavity thereof facing to ward the outside of the runner (200). The maximum value of the distance measured between any point on the peripheral edge (202) and a straight line passing through a first connection point between the peripheral edge (212) and the wheel (1), and through a second connection point between the peripheral edge (212) and the crown (12), is at an intermediate point on the peripheral edge (212). The radius (Rn) from the intermediate point (N) is strictly smaller than the radius (Ra) from the first connection point (A).

Abstract: This wheel comprises a plurality of vanes (2) arranged on a crown (3) and is equipped with a tip-forming member (10) attached to a central region (32) of the crown or hub of the wheel (1), radially inside the vanes (2), the crown defining a wet surface (31) for guiding a flow (E) passing between the vanes. The tip-forming member (10) is provided with at least one opening (121) for diverting a fraction (E1) of the flow towards the internal volume (V10) of this member. This member comprises a frustoconical annular skirt (11) and at least one fin (15) arranged in its internal volume (V10) and able to modify the path of the flow fraction (E1) entering this volume through the opening (121). This fin (15) extends as far as the edge (112) of the skirt (11) which defines an outlet opening (14) of the member (10) for the flow fraction (E1).

Abstract: This member (4) can be attached to the crown (12) of a wheel (1) of a hydraulic machine. It is provided with a skin (42) of which a surface (421) is able to be arranged in the continuation of a wet surface (121) of the crown. This member is equipped with at least one fun (43) arranged radially inside the skirt (42) and projecting axially (h) from the skirt (42) in the downward direction.