Constant-volume combustion (CVC) chamber for an aircraft turbine engine including an intake/exhaust valve having a spherical plug

1. A constant-volume combustion chamber for an aircraft turbine engine, the combustion chamber comprising:

a cylindrical side wall extending about a central chamber axis,

a compressed gas intake valve configured to adopt an open position and a closed position, in the closed position blocking intake of compressed gas into the combustion chamber, the compressed gas intake valve connected to an upstream end of the cylindrical side wall;

a combusted gas exhaust valve configured to adopt a closed position, in the closed position blocking exhaust of combusted gas outside the combustion chamber, the combusted gas exhaust valve connected to a downstream end of the cylindrical side wall;

an upstream seat orifice defined between the downstream end and the combusted gas exhaust valve, the upstream seat orifice having a first diameter centered on the central chamber axis;

a downstream seat orifice defined between the combusted gas exhaust valve and a hollow fixed body, the downstream seat orifice having a second diameter centered on the central chamber axis; and

a combustion enclosure radially defined by the cylindrical side wall and axially defined between the compressed gas intake valve and the combusted gas exhaust valve;

wherein at least one of the intake and exhaust valves comprises a spherical plug including:

an inner spherical body traversed by a gas passage, and

an outer spherical body housing the inner spherical body and including two mutually distant orifices,

wherein the inner and outer spherical bodies are rotatably mounted in relation to each other along an axis of rotation that is perpendicular to the central chamber axis, and the two mutually distant orifices of the outer spherical body form in conjunction with the gas passage a first diaphragm at a first end of the gas passage and a second diaphragm at a second end of the gas passage,

wherein after a gas exhaust phase resulting in closure of the exhaust valve,

the exhaust valve is placed in an exhaust gas recirculation (EGR) position where the first diaphragm and the second diaphragm are aligned along an axis perpendicular to the central chamber axis to allow combusted gases trapped in the gas passage to recirculate back to the combustion enclosure by transiting through the upstream seat orifice from both the first diaphragm and the second diaphragm because the first diameter is larger than the second diameter.

2. A combustion chamber according to claim 1 , wherein the inner and outer spherical bodies are mounted contra-rotating.

3. A combustion chamber according to claim 1 , wherein each of the two outer spherical body orifices and the two ends of the gas passage of the inner spherical body has, when viewed from the front, an oval overall shape with a length that extends perpendicularly to the axis of rotation of the inner spherical body in relation to the outer spherical body, and centers of the orifices of the outer spherical body and the first and second ends of the gas passage are arranged in a same plane orthogonal to the axis of rotation.

4. A combustion chamber according to claim 1 , further comprising at least one sealing element provided between the spherical plug and the hollow fixed body of the valve.

5. A combustion chamber module comprising: at least one chamber according to claim 1 , means for driving the spherical plug in rotation, the drive means configured to drive the spherical plug at a constant rotational speed.

6. A module according to claim 5 , comprising a plurality of combustion chambers distributed about a driving axis of the turbine engine.

7. A module according to claim 5 , wherein for at least one combustion chamber, the means for driving is configured to control the intake and exhaust valves in a synchronized fashion, with a phase shift.

8. An aircraft turbine engine comprising a combustion module according to claim 5 .

9. A combustion chamber according to claim 1 , wherein the first diaphragm and the second diaphragm are continuously diametrically opposed, and an opening cross-section of the first and second diaphragms are equal to each other at all positions of the inner and outer spherical bodies.

10. A combustion chamber according to claim 9 , wherein centers of the orifices of the outer spherical body and the first and second ends of the gas passage are aligned with the central chamber axis of the combustion chamber in a full opening position of the spherical plug.

11. A combustion chamber according to claim 10 , wherein the opening cross-sections of the first and second diaphragms in the full opening position is less than cross-sections of seat orifices of the intake and exhaust valves.