Abstract: A gas turbine engine includes an inner annular combustor radially inboard of an outer annular combustor. An outer variable turbine vane array is downstream of the outer annular combustor and an inner variable turbine vane array downstream of the inner annular combustor.

Abstract: The engine (10) includes a low spool (16) disposed aft of an air inlet (12) and a high spool (34) disposed aft of the low spool (16). An intake reverse-duct (44) is disposed radially outward of the high spool (34) and reverses direction of low pressure compressed air from the low spool (16) into a forward-flow high pressure compressor (40) of the high spool (34). A discharge reverse-manifold (48) directs flow of an exhaust gas stream (50} from a forward-flow low pressure turbine (20) into a rearward-flow direction and into at least one pulse detonation firing tube (54). An annular bypass air duct (72) directs cooling air along the engine (10)—The at least, one firing tube is positioned radially outward of the high spool (34), overlies the high spool (34) and is also positioned within the bypass air duct (72).

Abstract: A propulsion system and a method of operating the propulsion system according to an exemplary aspect of the present disclosure includes powering an auxiliary fan with a gas turbine engine, the auxiliary fan along an auxiliary axis and the gas turbine engine along an engine axis, the auxiliary axis parallel to the engine axis.

Abstract: A gas turbine engine according to an exemplary aspect of the present disclosure includes, among other things, a combustor section, a low spool including a fan section and an intercooling turbine section along an engine axis aft of the fan section and forward of a combustor section. The fan section and the intercooling turbine section are coaxial with the low spool. A high spool along the engine axis includes a high pressure compressor section and a high pressure turbine section, the high pressure compressor section is aft of the intercooling turbine section and forward of the combustor section, and the high pressure turbine section is aft of the combustor section. The high pressure compressor section and the high pressure turbine section are coaxial with the high spool. A method of operating a gas turbine engine is also disclosed.

Abstract: A gas turbine engine includes an intercooling turbine section to selectively cool the core flow. An intercooling turbine section bypass is also included to selectively bypass at least a portion of a core flow through an intercooling turbine section bypass path around the intercooling turbine section.

Abstract: A gas turbine engine includes an outer case structure around a central longitudinal engine axis. An intermediate case structure is included inboard of the outer case structure. An inner case structure is included inboard of the intermediate case structure. A variable area exhaust mixer is included, which is movable between a closed position adjacent to the intermediate case structure and an open position adjacent to the inner case structure.

Abstract: A gas turbine engine includes a combustor section, a fan section forward of the combustor section, a low pressure turbine section along the combustor section, and an intercooling turbine section aft of the fan section and forward of the combustor section. The intercooling turbine section includes upstream and downstream intercooling turbine variable vanes. The intercooling turbine section is situated in an intermediate flow path that is inboard of an outer bypass flow path. The intermediate flow path splits downstream from the intercooling turbine section to a second stream bypass flow path and a core flow path. The second stream bypass flow path is inboard of the outer bypass flow path and extends to an exhaust nozzle. The exhaust nozzle is located aft of the low pressure turbine section and inboard of the outer bypass flow path.

Abstract: A differential gear system for a gas turbine engine includes an assembly of a ring gear, a sun gear, and a plurality of planet gears, and a planet carrier. The plurality of planet gears are enmeshed between the ring gear and the sun gear. The planet carrier acts as an input to rotatably drive the planet gears, the sun gear, and ring gear of the gas turbine engine.

Abstract: A gas turbine engine comprises an outer engine case, a combustor, a high pressure spool and a low pressure spool. The combustor is disposed within the outer engine case. The high pressure spool is configured for rotation coaxially with the combustor. The low pressure spool is configured for rotation coaxially with the high pressure spool. The low pressure spool is configured to rotate at speeds faster than that of the high pressure spool during operation of the gas turbine engine. In one embodiment, the low pressure spool includes a gear system configured to rotate a low pressure compressor faster than a low pressure turbine. In another embodiment, the high pressure spool rotates outward of the combustor within the outer engine case. In another embodiment, the high pressure spool includes a drum having radially inward projecting blades and vanes and radially outward projecting fan blades.

Abstract: A gas turbine engine includes an intercooling turbine section to at least partially drive one of a low spool and a high spool. An intercooling turbine section bypass to selectively bypass at least a portion of a core flow through an intercooling turbine section bypass path around the intercooling turbine section.

Abstract: A gas turbine engine has a variable overall pressure rate (“OPR”). The engine includes a high pressure compressor having at least a primary stage having a set of primary rotors and a secondary stage having a set of secondary rotors. A clutch is provided to selectively engage the secondary rotors with the primary rotors. Engagement of the clutch may be controlled based on the vehicle travel mode, such as disengaging during a takeoff mode to reduce turbine entry temperature and engaging during a loiter mode to increase OPR.

Abstract: A gas turbine engine includes an intercooled twin centrifugal compressor. A pipe diffuser extends from the intercooled twin centrifugal compressor into an airflow path.

Abstract: A gas turbine engine includes a low spool along an engine axis with a forward fan section and a low pressure turbine section. A high spool along the engine axis with a high pressure turbine section and an aft core driven fan section (CDFS), the aft core driven fan section (CDFS) axially aft of the high pressure turbine section along the engine axis.

Abstract: A gas turbine engine has a variable overall pressure rate (“OPR”). The engine includes a high pressure compressor having at least a primary stage having a set of primary rotors and a secondary stage having a set of secondary rotors. A clutch is provided to selectively engage the secondary rotors with the primary rotors. Engagement of the clutch may be controlled based on the vehicle travel mode, such as disengaging during a takeoff mode to reduce turbine entry temperature and engaging during a loiter mode to increase OPR.

Abstract: A gas turbine engine with a two-spool fan and a method of operating the gas turbine engine includes modulating a pitch of a variable pitch first stage fan section of a low pressure spool, the variable pitch first stage fan section upstream of a second stage fan section of an intermediate pressure spool to maintain a generally constant engine inlet flow while modulating engine thrust.

Abstract: A gas turbine engine and a method of operating the gas turbine engine according to an exemplary aspect of the present disclosure includes modulating a variable high pressure turbine inlet guide vane of a high pressure spool to performance match a first stage fan section of a low pressure spool and an intermediate stage fan section of an intermediate spool to maintain a generally constant engine inlet flow while varying engine thrust.

Abstract: A propulsion system and a method of operating the propulsion system according to an exemplary aspect of the present disclosure includes powering an auxiliary fan with a gas turbine engine, the auxiliary fan along an auxiliary axis and the gas turbine engine along an engine axis, the auxiliary axis parallel to the engine axis.

Abstract: A gas turbine engine comprises an outer engine case, a combustor, a high pressure spool and a low pressure spool. The combustor is disposed within the outer engine case. The high pressure spool is configured for rotation coaxially with the combustor. The low pressure spool is configured for rotation coaxially with the high pressure spool. The low pressure spool is configured to rotate at speeds faster than that of the high pressure spool during operation of the gas turbine engine. In one embodiment, the low pressure spool includes a gear system configured to rotate a low pressure compressor faster than a low pressure turbine. In another embodiment, the high pressure spool rotates outward of the combustor within the outer engine case. In another embodiment, the high pressure spool includes a drum having radially inward projecting blades and vanes and radially outward projecting fan blades.

Abstract: A gas turbine engine includes a fan section and an intercooling turbine section along an engine axis aft of a fan section and forward of a combustor section.

Abstract: A gas turbine engine includes an intercooling turbine section to at least partially drive one of a low spool and a high spool. An intercooling turbine section bypass to selectively bypass at least a portion of a core flow through an intercooling turbine section bypass path around the intercooling turbine section.