A system for hybrid propulsion for an aircraft includes a gas turbine engine having a power shaft. A motor generator is operatively connected to the power shaft of the gas turbine engine and configured to produce electric power. An electric propulsion motor is configured to receive the electric power and be selectively driven at an operational speed independent of a rotational speed of the power shaft.

In one aspect the present subject matter is directed to a gas-electric propulsion system for an aircraft. The system may include a turbofan jet engine, an electric powered boundary layer ingestion fan that is coupled to a fuselage portion of the aircraft aft of the turbofan jet engine, and an electric generator that is electronically coupled to the turbofan jet engine and to the boundary layer ingestion fan. The electric generator converts rotational energy from the turbofan jet engine to electrical energy and provides at least a portion of the electrical energy to the boundary layer ingestion fan. In another aspect of the present subject matter, a method for propelling an aircraft via the gas-electric propulsion system is disclosed.

A gas turbine engine includes a compressor section and a turbine section together defining a core air flowpath. Additionally, a rotary component is rotatable with at least a portion of the compressor section and at least a portion of the turbine section. An electric machine is mounted coaxially with the rotary component and positioned at least partially inward of the core air flowpath along a radial direction of the gas turbine engine. An electric communication bus is electrically connected to the electric machine and extends through the core air flowpath to, e.g., electrically connect the electric machine to one or more systems of the gas turbine engine or a propulsion system including the gas turbine engine.

A boundary layer propulsor comprises a rotor and a plurality of first aerofoil blades. The rotor has an axis of rotation. The plurality of first aerofoil blades extends radially from the rotor and is arranged in a circumferential array around the axis of rotation. Each of the first aerofoil blades has, in a radially outward sequence, a radially proximal portion, a middle portion, and a radially distal portion. The radially proximal portion has a first cambered cross-section, the middle portion has a second uncambered cross-section, and the radially distal portion has a third cambered cross-section. The first cambered cross-section is cambered in an opposite sense to the third cambered cross-section.

An aircraft comprising a fuselage and a propulsion assembly, the propulsion assembly comprising at least one fan rotor located at the rear of the fuselage in the extension thereof along a longitudinal axis, and a nacelle forming a fairing of the at least one fan rotor into which a flow of air passes. The aircraft also comprises a plurality of radial stator arms mounted upstream of the at least one fan rotor and extending between the fuselage and the nacelle, the radial arms comprising blowing means configured for blowing, into the environment of a trailing edge of the radial arms, an additional air flow adding to the airflow in the extension of the trailing edge.

An aircraft is provided including a fuselage extending between a forward end and an aft end. An aft engine is mounted to the fuselage at the aft end of the fuselage. The aft engine includes a nacelle having a forward section. An airflow duct is also provided extending at least partially through the nacelle and including an opening on the forward section of the nacelle. The opening is configured for providing an airflow to, or receiving an airflow from, the forward section of the nacelle to increase an amount of, e.g., boundary layer airflow received within the aft engine during operation of the aircraft, to guide the flow of boundary layer airflow into the engine more smoothly, or to reduce a distortion on the engine.

An aircraft and flow guide system including a flow guide structure are provided. The aircraft has an airflow generator, and a duct extending from the airflow generator to an outlet through which an airflow generated by the airflow generator is expelled. The flow guide structure is positioned towards the outlet, and has a set of flow guide surfaces defining a plurality of channels. At least some of the flow guide surfaces divert at least some of the airflow from a first direction in which the airflow travels immediately upstream of the flow guide structure towards a second direction that is orthogonal to the first direction. The flow guide structure is reorientable to cause the at least some of the flow guide surfaces to divert at least some of the airflow towards a third direction that is orthogonal to the first direction.

An aircraft and flow guide system including a flow guide structure are provided. The aircraft has an airflow generator, and a duct extending from the airflow generator to an outlet through which an airflow generated by the airflow generator is expelled. The flow guide structure is positioned towards the outlet, and has a set of flow guide surfaces defining a plurality of channels. At least some of the flow guide surfaces divert at least some of the airflow from a first direction in which the airflow travels immediately upstream of the flow guide structure towards a second direction that is orthogonal to the first direction. The flow guide structure is reorientable to cause the at least some of the flow guide surfaces to divert at least some of the airflow towards a third direction that is orthogonal to the first direction.

A propulsion system for an aircraft is provided having an aft engine configured to be mounted to the aircraft at an aft end of the aircraft. The aft engine includes a fan rotatable about a central axis of the aft engine having a plurality of fan blades attached to a fan shaft. The aft engine also includes a nacelle encircling the plurality of fan blades and a structural support system for mounting the aft engine to the aircraft. The structural support system extends from the fuselage of the aircraft, through the fan shaft, and to the nacelle when the aft engine is mounted to the aircraft. The aft engine may increase a net thrust of the aircraft when mounted to the aircraft.

Systems and methods for integrating Boundary Layer Ingestion (BLI) apparatus into an aircraft (1) are disclosed. The longerons (34) in the aft fuselage (18) may be extended to support an aft propulsor (20). The aft propulsor may be a turbofan or turboelectric propulsion system (46). An upper longeron (34a) may support a tail section (14) of an aircraft. The aft fuselage skin (22) is contoured to permit boundary layer airflow to enter an intake fan (24) of the aft propulsor.