Air circulation device for turbomachine

1. A device for circulation of air for a turbomachine, the device comprising:

an inlet provided to receive incident airflow,

air circulation ducts connected to the inlet,

a central part comprising side walls,

peripheral walls arranged at a distance from the central part so as to form the air circulation ducts, each duct being arranged between one of the side walls of the central part and one of the peripheral walls, each peripheral wall comprising:

an upstream end portion delimiting with one of the side walls an inlet orifice of one of the ducts,

a downstream end portion delimiting with one of the side walls an outlet orifice of one of the ducts,

at least one member mobile in translation relative to the peripheral walls, the at least one mobile member being formed in the central part and arranged so that its displacement varies:

a section of each of the inlet orifices,

a section of at least one of the outlet orifices,

wherein:

the downstream end portion of each peripheral wall has a rectilinear profile,

each side wall of the central part successively comprises:

a first portion having a rectilinear profile,

a second portion having a profile curved at least in part and extending the first portion,

a third portion having a rectilinear profile, extending the second portion and extending in the same plane as the downstream end portion of a peripheral wall.

2. The device according to claim 1 , wherein the at least one mobile member comprises:

a first mobile member arranged so that its displacement simultaneously varies the section of each of the inlet orifices,

a second mobile member arranged so that its displacement varies the section of at least one outlet orifice independently of the first mobile member.

3. The device according to claim 2 , comprising a first actuator for shifting the first mobile member, and a second actuator for shifting the second mobile member.

4. The device according to claim 2 , wherein:

the first mobile member comprises the first rectilinear portion of a first of the side walls of the central part, and

the second mobile member comprises the second portion of the first side wall.

5. The device according to claim 4 , wherein the third portion of the first side wall is fixed relative to the peripheral wall facing the first side wall.

6. The device according to claim 4 , wherein the second portion and the third portion of a second of the side walls of the central part are fixed relative to the peripheral wall facing the second side wall.

7. The device according to claim 1 , wherein the at least mobile member comprises:

a first mobile member arranged so that its displacement simultaneously varies the section of each of the inlet orifices,

a second mobile member arranged so that its displacement varies the section of one of the outlet orifices, independently of the first mobile member,

a third mobile member arranged so that its displacement varies the section of another of the outlet orifices, independently of the first mobile member and independently of the second mobile member.

8. The device according to claim 7 , comprising a first actuator for shifting the first mobile member, a second actuator for shifting the second mobile member, and a third actuator for shifting the third mobile member.

9. The device according to claim 7 , comprising a first actuator for shifting the first mobile member, and a common actuator connected to the second mobile member and to the third mobile member to shift them simultaneously.

10. The device according to claim 7 , wherein:

the first mobile member comprises the first rectilinear portion of a first of the side walls and of a second of the side walls, and

the second mobile member comprises the second portion of the first side wall,

the third mobile member comprises the second portion of the second side wall.

11. The device according to claim 10 , wherein the third portion of the first side wall and the third portion of the second side wall are fixed relative to the peripheral walls.

12. The device according to claim 1 , wherein the at least one mobile member is a single mobile member arranged so that its displacement simultaneously varies:

the section of each of the inlet orifices, and

the section of each of the outlet orifices.

13. The device according to claim 12 , wherein, in each side wall,

the first portion is integral with the second portion,

the third portion is mobile relative to the first and second portions.

14. The device according to claim 12 , wherein the third portion of each side wall is fixed relative to the peripheral walls.

15. The device according to claim 1 , wherein the second portion of at least one of the side walls of the central part has an S-shaped profile.

16. The device according to claim 1 , wherein the second portion of at least one of the side walls of the central part comprises at least one end portion having a rectilinear profile, said end portion being adapted to slide with contact along one of the first and third portions of the side wall.

17. The device according to claim 16 , wherein the second portion comprises two opposite end portions which extend respectively in two planes parallel to each other.

18. The device according to claim 1 , comprising at least one actuator adapted in the event of breakdown to stress at least one mobile member towards a safety position wherein each orifice section varied by said member is maximal.

19. The device according to claim 1 , comprising at least one actuator adapted for shifting at least one mobile member and housed in a space between the side walls of the central part.