Abstract: An aircraft defines a vertical direction and includes a fuselage and a propulsion system comprising a power source and a plurality of vertical thrust electric fans driven by the power source. A wing extends from the fuselage. The plurality of vertical thrust electric fans are arranged along a length of the wing along a lengthwise direction of the wing. The wing comprises a diffusion assembly along the lengthwise direction of the wing and includes a first diffusion member positioned downstream of at least one of the plurality of vertical thrust electric fans. The first diffusion member defines a curved shape relative to a longitudinal direction of the aircraft. The longitudinal direction is generally perpendicular to the lengthwise direction of the wing.

Abstract: An aircraft includes a fuselage; a propulsion system including a power source and a vertical thrust propulsor driven by the power source; and a wing extending from the fuselage, the vertical thrust propulsor positioned on or at least partially within the wing, the wing including a diffusion assembly, the diffusion assembly including at least one diffusion member fixed in position and located downstream of the vertical thrust propulsor for diffusing an airflow from the vertical thrust propulsor.

Abstract: An aircraft includes a fuselage; a propulsion system including a power source and a vertical thrust electric fan driven by the power source; and a wing extending from the fuselage. The vertical thrust electric fan is positioned on or within the wing, the wing including a diffusion assembly movable between a first position and a second position and positioned at least partially downstream of the vertical thrust electric fan when in the second position, the diffusion assembly including a first member and a second member, the second member movable generally along the vertical direction relative to the first member such that the first member and second member together define at least in part an exhaust flowpath for the first vertical thrust electric fan when the diffusion assembly is in the second position.

Abstract: An aircraft includes a fuselage; a propulsion system including a power source and a plurality of vertical thrust electric fans driven by the power source; and a wing extending from the fuselage. The plurality of vertical thrust electric fans are arranged along the wing, the wing including one or more components being moveable to selectively expose the plurality of vertical thrust electric fans, the wing further including a diffusion assembly positioned downstream of at least one vertical thrust electric fan of the plurality of vertical thrust electric fans, the diffusion assembly defining a diffusion area ratio greater than 1:1 and less than about 2:1.

Abstract: An aircraft includes a fuselage; a propulsion system including a power source and a plurality of vertical thrust electric fans driven by the power source; and a wing extending from the fuselage. The plurality of vertical thrust electric fans are arranged along a length of the wing, the wing including a variable geometry assembly moveable generally along a horizontal direction between a forward thrust position and a vertical thrust position, the variable geometry assembly at least partially covering at least one vertical thrust electric fan of the plurality of vertical thrust electric fans when in the forward thrust position and at least partially exposing the at least one vertical thrust electric fan when in the vertical thrust position.

Abstract: An aircraft includes a fuselage; a propulsion system including a power source and a plurality of vertical thrust electric fans driven by the power source; and a wing extending from the fuselage. The plurality of vertical thrust electric fans are arranged along a length of the wing, the wing including a variable geometry assembly extending along the length of the wing and moveable between a forward thrust position and a vertical thrust position, the variable geometry assembly at least partially covering the plurality of vertical thrust electric fans when in the forward thrust position and at least partially exposing the plurality of vertical thrust electric fans when in the vertical thrust position.

Abstract: A gas turbine engine includes a compressor section defining a compressor exit temperature, T3. The gas turbine engine also includes a combustion section and a turbine section, with the turbine section defining a turbine inlet temperature, T4. A ratio, T4:T3, of the turbine inlet temperature, T4, to compressor exit temperature, T3, during operation of the gas turbine engine at a rated speed is less than or equal to 1.85.

Abstract: A method for operating an electric fan of an aircraft propulsion system includes driving a plurality of fan blades of the electric fan with an electric machine to generate thrust for the aircraft; and driving the electric machine with the plurality of fan blades of the electric fan to generate electrical power subsequent to driving the plurality of fan blades of the electric fan with the electric machine to generate thrust for the aircraft.

Abstract: A turbomachine and method for operating a turbomachine comprising a first rotatable component and a second rotatable component each defining a rotatable speed mechanically independent of one another, and an electric machine electrically coupled to the first rotatable component and the second rotatable component such that a load level relative to the first rotatable component and the second rotatable component is adjustable is generally provided.

Abstract: An aircraft defining a vertical direction and a transverse direction. The aircraft may include a fuselage, a wing extending from the fuselage, and a hybrid-electric propulsion system. The hybrid-electric propulsion system may include a power source, a plurality of vertical thrust electric fans arranged along the wing and driven by the power source, and a forward thrust propulsor. The power source may include a combustion engine and an electric generator. The combustion engine may also define a flowpath for exhausting combustion gases. The forward thrust propulsor may be selectively or permanently mechanically coupled to the combustion engine. The forward thrust propulsor may include a propulsor fan having a plurality of fan blades arranged outside of the flowpath of the combustion engine for exhausting combustion gases.

Abstract: A method for operating a vertical takeoff and landing aircraft includes modifying a first variable component of a wing associated with a first portion of the plurality of vertical thrust electric fans relative to a second variable component of the wing associated with a second portion of the plurality of vertical thrust electric fans to adjust an exposure ratio of the first portion of the plurality of vertical thrust electric fans relative to the second portion of the plurality of vertical thrust electric fans.

Abstract: A method for operating a propulsion system of an aircraft includes moving a plurality of forward and aft propulsors to a vertical thrust position. While in the vertical thrust positions, the method also includes providing a first forward to aft ratio of electric power to the plurality of forward and aft propulsors. The method also includes moving the plurality of forward and aft propulsors to a forward thrust position. While in the forward thrust positions, the method also includes providing a second forward to aft ratio of electric power to the plurality of forward and aft propulsors. The first forward to aft ratio of electric power is different than the second forward to aft ratio of electric power to provide certain efficiencies for the aircraft.

Abstract: An aircraft includes a fuselage; a propulsion system including a power source and a vertical thrust electric fan oriented to generate thrust along a vertical direction and powered by the power source; and a wing extending from the fuselage and including the vertical thrust electric fan positioned at least partially therein. The wing includes a variable geometry assembly having partial wing assembly, the partial wing assembly including a frame and a first member, the partial wing assembly moveable generally along a longitudinal direction when the variable geometry assembly is moved between a forward thrust position and a vertical thrust position, the first member moveable relative to the frame to form an exhaust path for the vertical thrust electric fan.

Abstract: A turbomachine and method for operation turbomachine are provided, the method including adjusting a first load at a first electric machine operably coupled to a first rotatable component, in which the first electric machine is operably coupled to the first rotatable component such that a first speed of the first rotatable component is increased or decreased based on an engine condition and the first load; adjusting a second load at a second electric machine operably coupled to a second rotatable component, in which the second electric machine is operably coupled to the second rotatable component such that a second speed of the second rotatable component is decreased or increased based on the engine condition and the second load; and transferring energy generated from at least one of the first electric machine or the second electric machine.

Abstract: An aircraft includes a fuselage; a wing coupled to, and extending from, the fuselage; and a hybrid-electric propulsion system. The hybrid-electric propulsion system includes a power source including a combustion engine and an electric generator; a plurality of vertical thrust electric fans integrated into the wing and oriented to generate thrust along the vertical direction, the plurality of vertical thrust electric fans arranged along a length of the wing and driven by the power source; and a forward thrust propulsor. The forward thrust propulsor it is selectively or permanently mechanically coupled to the combustion engine.

Abstract: An aircraft includes a fuselage; a wing coupled to, and extending from, the fuselage; and a propulsion system. The propulsion system includes a plurality of electric fans integrated into the wing and oriented to generate thrust along a vertical direction, the plurality of electric fans arranged along a length of the wing and including an outer-most electric fan along a transverse direction relative to the fuselage. The outer-most electric fan is at least one of a variable pitch fan or a variable speed fan to provide increased stability to the aircraft.

Abstract: An electric machine for a drive system having a first DS rotor and a second DS rotor includes a first EM rotor rotatable about an axis in a first circumferential direction and including a plurality of magnets, the first EM rotor configured for mechanical coupling to the first DS rotor; and a second EM rotor rotatable about the axis in a second circumferential direction and including a plurality of windings, the second EM rotor configured for mechanical coupling to the second DS rotor and the plurality of magnets of the first EM rotor operably engaged with the plurality of windings of the second EM rotor.

Abstract: A turbomachine and method for operating a turbomachine comprising a first rotatable component and a second rotatable component each defining a rotatable speed mechanically independent of one another, and an electric machine electrically coupled to the first rotatable component and the second rotatable component such that a load level relative to the first rotatable component and the second rotatable component is adjustable is generally provided.

Abstract: A permanent magnet machine and a rotor assembly for the permanent magnet machine. The permanent magnet machine includes a stator assembly including a stator core including a stator winding to produce electrical currents. The stator assembly extending along a longitudinal axis with an inner surface defining a cavity. The rotor assembly including a rotor core and a rotor shaft. The rotor core is disposed inside the stator cavity and rotates about the longitudinal axis. The rotor assembly including a plurality of permanent magnets for generating a magnetic field which interacts with the stator winding to produce the electrical currents in response to rotation of the rotor assembly. within one or more cavities formed in a sleeve component. The sleeve component is configured to include a plurality of cavities or voids into which the permanent magnets are disposed to retain the permanent magnets therein and form an interior permanent magnet generator.

Abstract: A method is provided for operating a propulsion system of a vertical takeoff and landing aircraft, the propulsion system including a turbomachine, an electric machine, a forward thrust propulsor, and a plurality of vertical thrust electric fans. The method includes driving the forward thrust propulsor with the turbomachine; rotating the electric machine with the turbomachine to generate electrical power; determining a failure condition of the turbomachine; and providing electrical power to the electric machine to drive the forward thrust propulsor with the electric machine in response to determining the failure condition of the turbomachine.