The present invention includes an air flow bypass for a tiltrotor engine comprising: a ram air inlet comprising bypass door(s) capable of at least partially or fully blocking a ram air flow through the ram air inlet; a barrier filter inlet positioned in a side, a bottom, and/or a top of a tiltrotor engine nacelle; a filter plenum; a selector duct comprising one or more openings; and one or more selector duct doors or covers over the one or more openings; wherein the barrier filter inlet, the filter plenum, the one or more openings in the selector duct, the selector duct, and an engine are in fluid communication and the bypass door(s) in the ram inlet are closed and the barrier filter inlet provides filtered air flow to the engine when the aircraft is in hover operations.

A propulsion system for an aircraft has at least two fans with each fan having a fan drive shaft. A turboshaft gas turbine engine drives each of the at least two fans. The turboshaft engine drives an output shaft which drives a gear to, in turn, engage to drive a gear on a first intermediate shaft extending from the turboshaft gas turbine engine in a rearward direction toward an intermediate fan drive shaft. The intermediate fan drive shaft drives the fan drive shaft, and the at least two first intermediate drive shafts extending over a distance that is greater in an axial dimension defined between the turboshaft gas turbine engine and the fan than it is in a width dimension defined between the at least two fans.

Gas turbine engines include a compressor section having an impeller configured to compress a core flow. A combustor section having a combustor is arranged downstream from the compressor section along a path of the core flow. A turbine section is arranged downstream from the combustor section along the path of the core flow, with the turbine section having a plurality of first vanes arranged at an outlet of the combustor and at least one first vane of the plurality of first vanes includes an internal vane path. The path of the core flow, in a flow direction, passes through the impeller of the compressor section, the internal vane path internal to the first vane, the combustor, and then between external surfaces of the plurality of first vanes to enter the turbine section.

The present invention includes an air flow bypass for a tiltrotor engine comprising: a ram air inlet comprising bypass door(s) capable of at least partially or fully blocking a ram air flow through the ram air inlet; a barrier filter inlet positioned in a side, a bottom, and/or a top of a tiltrotor engine nacelle; a filter plenum; a selector duct comprising one or more openings; and one or more selector duct doors or covers over the one or more openings; wherein the barrier filter inlet, the filter plenum, the one or more openings in the selector duct, the selector duct, and an engine are in fluid communication and the bypass door(s) in the ram inlet are closed and the barrier filter inlet provides filtered air flow to the engine when the aircraft is in hover operations.

A compound engine assembly including a common air conduit having an inlet in fluid communication with ambient air, a compressor, at least one internal combustion engine 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 at least one internal combustion engine, the turbine section configured to compound power with the at least one internal combustion engine, and at least one heat exchanger in fluid communication with the common air conduit, each of the at least one heat exchanger configured to circulate a fluid of the engine assembly in heat exchange relationship with an airflow from the common air conduit circulating therethrough. The compressor has an inlet in fluid communication with the common air conduit upstream of the at least one heat exchanger. The internal combustion engine may be a reciprocating engine.

A turboprop assembly includes a nacelle with a main nacelle body and a nacelle extension coupled to the main nacelle body. The nacelle extension has a wall that defines an air intake port. The air intake port has a non-circular, non-rectangular, and non-oval shaped perimeter extending in two of three dimensions.

Air intake duct for supplying air to a turbine engine gas generator, in particular an aircraft turbine engine, extending axially between the air intake and the gas generator and having a deflection which may cause shedding of the boundary layer formed by the air flow along the wall of the duct, wherein said air intake duct comprises a guiding element located in the duct and designed to guide the air along the wall of the duct to a portion having the deflection, said guiding element extending transversely to the direction of the flow of air and having at the ends thereof two end profiles that form a non-zero angle with the guiding element, said two end profiles being able to produce eddies in the air flow.

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.

An aircraft power plant is disclosed having a plurality of bladed rotors in flow communication driven by separate work producing devices. The work producing devices can take a variety of forms including an internal combustion engine and electric motor, for example. The bladed rotors can be associated with an aircraft pylon and can be driven independently to separate operating conditions to provide optimum performance. For example, the bladed rotors can be driven to separate operating conditions that improve a noise signature or performance of the aircraft.

A device for filtering a flow of gas conveying liquid or solid particles in a flow channel. According to the invention, the particles are imparted a speed that is high enough to project same by inertia into the opening of a recovery channel formed inside the flow channel, while the gas from the flow bypasses said opening due to a specific configuration of the flow conditions of a perfect fluid in the flow channel and in the collection channel.