Hydraulic machine including means for injecting a flow drawn from a main flow

1. A hydraulic machine of the Francis turbine type, comprising a rotor traversed by a main flow (E) of water, the rotor having a plurality of blades positioned between a ceiling and a belt, each blade having an upstream end and a downstream end, at least one eddy zone, a reduced-pressure zone or a cavitation zone being formed adjacent the downstream end of each blade during rotation of the rotor, injection means for injecting first and second flows (E 1 , E 2 ) tapped from the main flow, and not modified relative to the main flow (E), into the eddy, reduced-pressure or cavitation zone so as to modify the main flow (E) or increase the pressure in the zone, wherein the injection means for injecting the first flow (E 1 ) includes a duct extending through each blade in a direction of the main flow (E) and having an inlet opening for the first tapping flow (E 1 ) from the main flow (E) in a side wall of each blade adjacent the upstream end of each blade and an outlet opening in the downstream end of each blade so as to discharge the first flow (E 1 ) tapped from the main flow (E) in the direction of the main flow (E), and wherein the second flow (E 2 ) is tapped from the ceiling or the belt through openings formed in the ceiling or in the belt and passes through other openings in the blade which communicate with the outlet opening in the downstream end of each blade so as to discharge the second flow (E 2 ) in the direction of the main flow (E).

2. The hydraulic machine according to claim 1 , wherein the outlet opening is into the eddy, reduced-pressure or cavitation zone.

3. The hydraulic machine according to claim 2 , including valves mounted in the openings in the ceiling or the belt for regulating the second flow (E 2 ) through the ceiling or the belt.

4. The hydraulic machine according to claim 3 , wherein movement of each valve is controlled by a controller.