A system and method of an airflow control system for a vehicle is described herein. The airflow control system (100) includes an airflow housing (120) defining an airflow passageway (125) extending between a bypass opening (122) and an intake outlet (124). The airflow housing also defines a duct opening (126) positioned between the bypass opening (122) and the intake outlet (124). The intake outlet (124) may be in fluid communication with an engine intake (12) of the vehicle such that air passes from the bypass opening (122) and/or the duct opening (126) to the engine intake (12). The airflow control system (100) also includes a movable duct (160) movably connected to the airflow housing (120) to selectively allow or prevent air passage through the duct opening (126) and into the engine intake (12), and further includes a bypass door (140) movably connected to the airflow housing (120) to selectively allow or prevent air passage through the bypass opening (122) and into the engine intake (12).

Apparatuses and systems are provided herein for unducted propulsion systems. The system includes an aft housing for low drag for high subsonic sustained flight. A plurality of blades are affixed to the aft housing, wherein the housing defines a flowpath curve extending from the axial extent of the aft blade root to the aft end of the aft housing. The flowpath curve is described by an axial direction parallel to an axis of rotation and a radius from the axis of rotation. The flowpath curve includes first point having a first radius where the radius reaches a maximum aft of the aft blade root and a second point forward of the first point having a second radius where the radius stops decreasing. The ratio of the first radius to the second radius is greater than or equal to 1.081.

A propulsion system is provided including an unducted rotating fan defining a fan axis; and a turbomachine disposed downstream from the unducted rotating fan, wherein the turbomachine defines a working gas flowpath flowing therethrough; wherein the propulsion system defines a third stream flowpath and an inlet passage having an inlet that is offset from the fan axis, wherein the inlet passage is configured to provide an inlet airflow to the working gas flowpath, and wherein the third stream flowpath bypasses at least a portion of the turbomachine.

A turboprop gas turbine engine mountable to an aircraft has an engine core and a gearbox driving a propeller, the engine core and the gearbox being enclosed within a nacelle. The propeller is located rearward of the gearbox and the engine core relative to a direction of travel of the aircraft. An air intake is disposed within the nacelle and formed to direct ambient air into the engine core. The air intake includes an air inlet duct, having a forward-facing intake inlet receiving the ambient air, with an upstream section and a downstream section. The upstream section is in fluid communication with the intake inlet and extends downstream from the intake inlet. The downstream section fluidly connects to and directs air from the upstream section into the engine air inlet. A second air outlet duct is located within the nacelle and directs air into an air-cooled-oil-cooler (ACOC).

An inertial particle separator (IPS) for a gas turbine engine, has: a plenum circumferentially extending about a central axis and defined between an outer wall and an inner wall, the plenum having an inlet facing a circumferential direction relative to the central axis, a radius of the outer wall decreasing in an axial direction relative to the central axis between the inlet and an annular splitter extending circumferentially around the central axis and located downstream of the inlet radially between the outer wall and the inner wall, a particle outlet including an annulus radially between the outer wall and the splitter, an air outlet fluidly connectable to a compressor of the gas turbine engine and defined radially between the splitter and the inner wall.

A compound engine assembly including an air conduit having an inlet in fluid communication with ambient air around the compound engine assembly, a compressor having an inlet in fluid communication with the air conduit, an engine core including at least one rotary internal combustion engine and having an inlet in fluid communication with an outlet of the compressor, a turbine section having an inlet in fluid communication with an outlet of the engine core and configured to compound power with the engine core; and at least one heat exchanger in fluid communication with the air conduit, each heat exchanger configured to circulate a fluid of the engine assembly in heat exchange relationship with an airflow from the air conduit circulating therethrough. A method of supplying air to a compound engine assembly is also discussed.

An air intake for efficiently channeling a flow of ambient air toward an air inlet of a turboprop or turboshaft gas turbine engine is disclosed. The air intake comprises an intake inlet for receiving the flow of air, an intake duct for channelling the flow of air, and an intake outlet for discharging the flow of air toward the air inlet of the gas turbine engine. The intake duct may be oriented toward a flow direction of the air pushed aft by a propeller coupled to the gas turbine engine.

An air intake for efficiently channeling a flow of ambient air toward an air inlet of a turboprop or turboshaft gas turbine engine is disclosed. The air intake comprises an intake inlet for receiving the flow of air, an intake duct for channelling the flow of air, and an intake outlet for discharging the flow of air toward the air inlet of the gas turbine engine. The air intake may comprise a scroll portion and a strutted portion configured to receive the flow of air from the intake duct and channel the flow of air toward the intake outlet. The strutted portion may comprise one or more vanes for interacting with the flow of air. The intake duct may be oriented toward a flow direction of the air pushed aft by a propeller coupled to the gas turbine engine.

An aircraft includes a fuselage and an engine housed in the fuselage. A ram-air engine inlet is formed on an exterior of the fuselage. The ram-air engine inlet is defined, at least in part, by a cowling door. The cowling door is moveable between a closed position and an open position. An intake duct fluidly couples the ram-air engine inlet to the engine. A filter is disposed across the intake duct. A bypass duct is formed in the ram-air engine inlet aft of the intake duct. The bypass duct is operable to be selectively opened and closed.

An apparatus for providing foreign object debris protection and anti-icing capabilities to an air intake of an aircraft engine. The apparatus includes a frame having at least a portion configured to conduct fluids. A tube is positioned such that different portions of the frame are fluidly connected. There is a discharge outlet defined within the frame that is configured to discharge fluids from the frame into the air intake. An inlet is defined within the frame and is fluidly connected to a compressor section of the aircraft engine. In this manner, air from the compressor section of the aircraft engine can flow through the inlet, through the tube, and through the discharge outlet, to return to the compressor section of the aircraft engine.