Combined cycle propulsion system for hypersonic flight
A combined cycle propulsion system for a flight vehicle includes a compressor-fed combustion engine, and a multi-mode supersonic engine. The multi-mode supersonic engine includes an adjustable inlet section, a combustion section arranged downstream of the adjustable inlet section and including a first combustor portion having at least one rotating detonation combustor and a second combustor portion having a supersonic combustion type combustor, and an adjustable exhaust nozzle section arranged downstream of the combustion section. The at least one rotating detonation combustor functions as a pilot for the supersonic combustion type combustor.
1. A combined cycle propulsion system for a flight vehicle, the combined cycle propulsion system comprising:
a compressor-fed combustion engine; and
a multi-mode supersonic engine including, in a serial flow relationship defining a supersonic engine gas flowpath:
an adjustable inlet section having an inlet at an upstream end of the adjustable inlet section;
a combustion section arranged downstream of, and in fluid communication with, the adjustable inlet section and including a first combustor portion having at least one rotating detonation combustor and a second combustor portion having a supersonic combustion type combustor; and
an adjustable exhaust nozzle section arranged downstream of, and in fluid communication with, the combustion section,
wherein the at least one rotating detonation combustor functions as an ignition source for the supersonic combustion type combustor,
wherein the compressor-fed combustion engine includes an outer casing extending circumferentially about a centerline axis of the compressor-fed combustion engine, and the multi-mode supersonic engine extends circumferentially about the centerline axis and is arranged radially outward of the outer casing,
the outer casing extending from the inlet of the adjustable inlet section to the adjustable exhaust nozzle section and having an outer casing inner wall and an outer casing outer wall, the outer casing outer wall being an inner wall of the multi-mode supersonic engine extending from the inlet of the adjustable inlet section to the adjustable exhaust nozzle section, and
a cooling airflow passage is defined between the outer casing inner wall and the outer casing outer wall from the inlet of the adjustable inlet section to the adjustable exhaust nozzle section to provide a flow of cooling air therethrough to provide cooling to the inner wall of the multi-mode supersonic engine.
2. The combined cycle propulsion system according to claim 1 , wherein the compressor-fed combustion engine, the first combustor portion and the second combustor portion each respectively operate utilizing a first fuel type, a second fuel type different from the first fuel type, or a third fuel type different from the first fuel type and different from the second fuel type.
3. The combined cycle propulsion system according to claim 1 , wherein the first combustor portion and the second combustor portion are arranged in a serial relationship, the second combustor portion being arranged downstream of the first combustor portion.
4. The combined cycle propulsion system according to claim 3 , wherein the at least one rotating detonation combustor is a single rotating detonation combustor that extends circumferentially about the centerline axis.
5. The combined cycle propulsion system according to wherein the first combustor portion includes a combustor bypass flow passage at the single rotating detonation combustor providing a flow of bypass air from upstream of the single rotating detonation combustor to flow downstream of the single rotating detonation combustor to the second combustor portion.
6. The combined cycle propulsion system according to claim 1 , wherein the at least one rotating detonation combustor of the first combustor portion includes a plurality of rotating detonation combustors circumferentially spaced about the centerline axis of the compressor-fed combustion engine.
7. The combined cycle propulsion system according to claim 6 , wherein a plurality of bypass flow passages are provided between respective ones of the plurality of rotating detonation combustors, to provide a bypass airflow through the plurality of bypass flow passages to the second combustor portion.
8. The combined cycle propulsion system according to claim 1 , wherein the cooling airflow passage includes a plurality of air bleed openings arranged to provide a flow of a portion of the cooling air to pass from the cooling airflow passage into component parts of the supersonic engine.
9. The combined cycle propulsion system according to wherein the adjustable inlet section includes at least one actuator, the adjustable inlet section being adjustable via the at least one actuator to adjust an inlet flow of air to the multi-mode supersonic engine based on (a) a first supersonic operation mode in which the first combustor portion is operated and the second combustor portion is not operated, (b) a second supersonic operation mode in which the second combustor portion is operated and the first combustor portion is not operated, and (c) a transitional supersonic operation mode between the first supersonic operation mode and the second supersonic operation mode in which both the first combustor portion and the second combustor portion are operating.
10. The combined cycle propulsion system according to claim 9 , wherein the second combustor portion comprises a scramjet combustor; and wherein in the first supersonic operation mode, the at least one rotating detonation combustor is operating and the scramjet combustor is not operating; in the second supersonic operation mode, the scramjet combustor is operating and the at least one rotating detonation combustor is not operating; and, in the transitional supersonic operation mode, the at least one rotating detonation combustor is operating as a pilot to the scramjet combustor.
11. The combined cycle propulsion system according to claim 10 , wherein the adjustable exhaust nozzle section includes at least one exhaust nozzle actuator, the adjustable exhaust nozzle section being actuated: a) in the first supersonic operation mode, to define a converging exhaust outlet, b) in the second supersonic operation mode, to define a diverging exhaust outlet, and c) in the transitional supersonic operation mode, to transition between the converging exhaust outlet and the diverging exhaust outlet.