Abstract: Aspects of the disclosure generally relate to an aircraft propulsion system for an aircraft. The aircraft propulsion system can include at least an electric power source, an electric machine, and a voltage regulator. The voltage regulator regulates the electrical power provided to the electric machine from the electrical power source. The electric power source is capable of providing an AC or DC electrical output and can include a combustion engine with a generator or an electrical storage device.

Abstract: The present disclosure is directed to turbine engines and systems for active stability control of rotating compression systems utilizing an electric machine operatively coupled thereto. In one exemplary aspect, an electric machine operatively coupled with a compression system, e.g., via a shaft system, is controlled to provide shaft damping for instability fluctuations of the pressurized fluid stream within the compression system. Based on control data indicative of a system state of the compression system, a control parameter of the electric machine is adjusted to control or change an output of the shaft system. Adjusting the shaft system output by adjusting one or more control parameters of the electric machine allows the compression system to dampen instability fluctuations of the fluid stream within the compression system. A method for active stability control of a compression system operatively coupled with an electric machine via a shaft system is also provided.

Abstract: The present disclosure is directed to turbine engines and systems for active stability control of rotating compression systems utilizing an electric machine operatively coupled thereto. In one exemplary aspect, an electric machine operatively coupled with a compression system, e.g., via a shaft system, is controlled to provide shaft damping for instability fluctuations of the pressurized fluid stream within the compression system. Based on control data indicative of a system state of the compression system, a control parameter of the electric machine is adjusted to control or change an output of the shaft system. Adjusting the shaft system output by adjusting one or more control parameters of the electric machine allows the compression system to dampen instability fluctuations of the fluid stream within the compression system. A method for active stability control of a compression system operatively coupled with an electric machine via a shaft system is also provided.

Abstract: Aspects of the disclosure generally relate to an aircraft propulsion system for an aircraft. The aircraft propulsion system can include at least an electric power source, an electric machine, a voltage regulator, and at least one propeller. The voltage regulator regulates the electrical power provided to the electric machine from the electrical power source. The electric power source is capable of providing an AC or DC electrical output and can include a combustion engine with a generator or an electrical storage device.

Abstract: A multi-spool turbomachine having an electric machine that can be controlled to input power to one of the spools of the turbomachine is provided. In one aspect, the multi-spool turbomachine can be a hybrid electric gas turbine engine for an aircraft. The hybrid electric gas turbine engine can include a first spool, a second spool, and an electric machine operatively coupled with the first spool. In response to an increase in thrust demand, the electric motor receives electrical power from an electrical power source. In turn, the electric machine applies a torque to the first spool, causing the first spool to increase in rotational speed. In this manner, the electric machine can electrically assist the turbomachine to meet the increase in thrust demand.

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: Methods and apparatus to project aircraft zone indications are disclosed. A disclosed example projection system for displaying an indicator pertaining to an aircraft includes a condition analyzer to determine a condition of at least one of the aircraft or a zone surrounding the aircraft, and a projector to project the indicator on or proximate the zone based on the determined condition.

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: Methods and apparatus to project aircraft zone indications are disclosed. A disclosed example projection system for displaying an indicator pertaining to an aircraft includes a condition analyzer to determine a condition of at least one of the aircraft or a zone surrounding the aircraft, and a projector to project the indicator on or proximate the zone based on the determined condition.

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: 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 multi-spool turbomachine having an electric machine that can be controlled to input power to one of the spools of the turbomachine is provided. In one aspect, the multi-spool turbomachine can be a hybrid electric gas turbine engine for an aircraft. The hybrid electric gas turbine engine can include a first spool, a second spool, and an electric machine operatively coupled with the first spool. In response to an increase in thrust demand, the electric motor receives electrical power from an electrical power source. In turn, the electric machine applies a torque to the first spool, causing the first spool to increase in rotational speed. In this manner, the electric machine can electrically assist the turbomachine to meet the increase in thrust demand.

Abstract: Aspects of the disclosure generally relate to an aircraft propulsion system for an aircraft. The aircraft propulsion system can include at least an electric power source, an electric machine, a voltage regulator, and at least one propeller. The voltage regulator regulates the electrical power provided to the electric machine from the electrical power source. The electric power source is capable of providing an AC or DC electrical output and can include a combustion engine with a generator or an electrical storage device.

Abstract: An aircraft includes an electric power source having a combustion engine and an electric generator. The electric generator is powered by the combustion engine. The aircraft also includes a propulsion assembly including a propulsor and an electric motor, the electric motor configured for rotating the propulsor. The aircraft also includes an electrical outlet configured for connection with an outside power sink. The electrical outlet and the propulsion assembly are selectively in electrical communication with the electric power source such that the electric power source selectively provides electrical power to one of the electrical outlet or the propulsion assembly.

Abstract: The present disclosure is directed to turbine engines and systems for active stability control of rotating compression systems utilizing an electric machine operatively coupled thereto. In one exemplary aspect, an electric machine operatively coupled with a compression system, e.g., via a shaft system, is controlled to provide shaft damping for instability fluctuations of the pressurized fluid stream within the compression system. Based on control data indicative of a system state of the compression system, a control parameter of the electric machine is adjusted to control or change an output of the shaft system. Adjusting the shaft system output by adjusting one or more control parameters of the electric machine allows the compression system to dampen instability fluctuations of the fluid stream within the compression system. A method for active stability control of a compression system operatively coupled with an electric machine via a shaft system is also provided.

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: A propulsion system for an aircraft includes an electric generator mechanically driven by a combustion engine, with the electric generator configured to generate alternating current electrical power. The propulsion system additionally includes a power bus electrically connected to the electric generator and configured to receive and transmit the alternating current electrical power generated by the electric generator. Additionally, the propulsion system includes, an electric propulsor assembly comprising an electric motor and a propulsor drivingly connected to the electric motor, the electric motor electrically coupled to the power bus for the receiving alternating current electrical power from the power bus.

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.