Central cooling circuit for a moving blade of a turbomachine

1. A moving blade for a turbomachine, the central portion of the blade being geometrically subdivided into four adjacent pressure-side zones disposed on the pressure side of the blade, and into four adjacent suction-side zones disposed on the suction side, the pressure-side and suction-side zones being distributed on opposite sides of the skeleton of the blade, the blade including in its central portion both a pressure-side cooling circuit and a suction-side cooling circuit that are independent from each other, the pressure-side cooling circuit comprising three radial cavities occupying three adjacent pressure-side zones, and the suction-side cooling circuit comprising three radial cavities occupying the four suctionside zones and the remaining pressure-side zone,

wherein the blade further includes a trailing edge cooling circuit that is independent from the pressure-side and suction-side cooling circuits and that comprises at least one radial cavity in the vicinity of the trailing edge of the blade, at least one air admission orifice opening into the cavity of the trailing edge cooling circuit, and outlet orifices opening out into the trailing edge of the blade.

2. A blade according to claim 1 , in which the suction-side cooling circuit comprises:

a first cavity and a second cavity extending on the suction side of the blade;

a third cavity extending from the pressure side to the suction side of the blade;

an air admission opening at one radial end of the first cavity;

a first passage causing the other radial end of the first cavity to communicate with an adjacent radial end of the second cavity;

a second passage causing the other radial end of the second cavity to communicate with an adjacent radial end of the third cavity; and

outlet orifices opening from the third cavity out into the pressure-side face of the blade.

3. A blade according to claim 2 , in which the third cavity of the suction-side cooling circuit is disposed beside the trailing edge of the blade.

4. A blade according to claim 2 , in which the third cavity of the suction-side cooling circuit is disposed beside the leading edge of the blade.

5. A blade according to claim 1 , in which the suction-side cooling circuit comprises:

a first cavity and a second cavity extending on the suction side of the blade;

a third cavity extending on the pressure side of the blade;

an air admission opening at one radial end of the first cavity;

a first passage causing the other radial end of the first cavity to communicate with an adjacent radial end of the second cavity;

a second passage causing the other radial end of the second cavity to communicate with an adjacent radial end of the third cavity; and

outlet orifices opening from the third cavity out into the pressure-side face of the blade.

6. A blade according to claim 5 , in which the third cavity of the suction-side cooling circuit is disposed beside the leading edge of the blade.

7. A blade according to claim 5 , in which the third cavity of the suction-side cooling circuit is disposed beside the trailing edge of the blade.

8. A blade according to claim 1 , in which the pressure-side cooling circuit comprises:

first, second, and third cavities extending on the pressure side of the blade;

an air admission opening at a radial end of the first cavity;

a first passage causing the other radial end of the first cavity to communicate with an adjacent radial end of the second cavity;

a second passage causing the other radial end of the second cavity to communicate with an adjacent radial end of the third cavity; and

outlet orifices opening from the third cavity out into the pressure-side face of the blade.

9. A blade according to claim 1 , further including a leading edge cooling circuit comprising:

a first radial cavity extending in the vicinity of the leading edge of the blade;

a second radial cavity extending from the pressure side to the suction side of the blade, said second cavity being disposed between the first cavity and the central portion of the blade;

an air admission opening opening into the second cavity;

a plurality of communication holes distributed over the entire radial height of the blade, opening from the second cavity out into the first cavity; and

outlet orifices opening from said first cavity out into the leading edge and into the pressure-side and suction-side faces of the blade.

10. A blade according to claim 1 , wherein said trailing edge cooling circuit comprises:

a first radial cavity extending in the vicinity of the trailing edge of the blade;

a second radial cavity extending from the pressure side to the suction side of the blade, said second cavity being disposed between the first cavity and the central portion of the blade;

at least one air admission orifice opening into the second cavity;

a plurality of communication holes distributed over the radial height of the blade opening from the second cavity out into the first cavity; and

outlet orifices opening from said first cavity out into the trailing edge of the blade.

11. A gas turbine, including at least one moving blade according to claim 1 .

12. A turbomachine, including at least one moving blade according to claim 1 .

13. A blade according to claim 1 , wherein the three cavities of the pressure-side cooling circuit extend in the thickness direction of the blade from its pressure-side face to its skeleton only.

14. A blade according to claim 1 , wherein one of the three cavities of the suction-side cooling circuit is disposed beside the leading edge of the blade.