Combustion chamber of a turbomachine including cooling grooves

1. An annular combustion chamber of a turbomachine, comprising:

inner and outer coaxial walls of revolution extending one inside the other and delimiting therebetween the chamber, each coaxial wall comprising at least one annular groove extending around a longitudinal axis of the chamber and opening out inside the chamber, the groove being supplied with cooling air through orifices formed in said coaxial wall and opening out at a first end of said orifices in the groove and at a second end of said orifices outside the chamber,

wherein the groove has in cross section a substantially V shape and comprises inner and outer lateral annular surfaces which diverge one from the other towards a downstream end,

wherein the inner lateral annular surface of the outer coaxial wall groove is connected to an inner annular surface of said outer coaxial wall and extends upstream to downstream towards an inside of the chamber and is inclined with respect to said inner annular surface of said outer coaxial wall, and/or the outer lateral annular surface of the inner coaxial wall groove is connected to an outer annular surface of said inner coaxial wall and extends upstream to downstream towards the inside of the chamber and is inclined with respect to said outer annular surface of said inner coaxial wall.

2. The chamber according to claim 1 , wherein the groove is formed at the downstream end of each coaxial wall of the chamber, close to an annular flange for fixing said coaxial wall to a casing of the chamber.

3. The chamber according to claim 1 , wherein an angle formed between each lateral surface of the groove and an area of said coaxial wall where the groove is situated is between approximately 5° and 35° .

4. The chamber according to claim 1 , wherein the lateral surfaces of the groove diverge from each other towards the downstream end by an angle of between approximately 2° and 10° .

5. The chamber according to claim 1 , wherein the downstream end of the groove is wider than a base of the groove by approximately 1 to 2 mm.

6. The chamber according to claim 1 , wherein the groove is supplied with cooling air by an annular row of first orifices that extend substantially parallel to an area of said coaxial wall where the groove is situated.

7. The chamber according to claim 6 , wherein the groove is supplied with cooling air by an annular row of second orifices that are substantially perpendicular to the area of said coaxial wall where the groove is situated.

8. The chamber according to claim 7 , wherein said first orifices are disposed so as to be staggered with said second orifices.

9. The chamber according to claim 1 , wherein said orifices open out at one of their ends at the bottom of the groove.

10. The chamber according to claim 1 , wherein said orifices have a diameter of between approximately 0.5 and 2 mm.

11. The chamber according to claim 1 , wherein the chamber comprises between 100 and 500 orifices supplying the groove with cooling air.

12. A turbomachine comprising a combustion chamber according to claim 1 .

13. The turbomachine according to claim 12 , comprising a distributor mounted downstream of the combustion chamber, the distributor comprising radially inner and outer cylinders which blades extend, wherein a downstream end part of an external coaxial wall of the chamber where the groove is situated has a diameter that increases towards the downstream end and is slightly less than an inside diameter of said radially outer cylinder of the distributor.

14. The chamber according to claim 1 , wherein upstream ends of the lateral surfaces of the groove are connected with each other by a groove bottom with a concave rounded shape.