An aircraft propulsion system with a drag reduction portion adapted to reduce skin friction on at least a portion of the external surface of an aircraft. The drag reduction portion may include an inlet to ingest airflow. The aircraft may also have an internally cooled electric motor adapted for use in an aerial vehicle. The motor may have its stator towards the center and have an external rotor. The rotor structure may be air cooled and may be a complex structure with an internal lattice adapted for airflow. The stator structure may be liquid cooled and may be a complex structure with an internal lattice adapted for liquid to flow through. A fluid pump may pump a liquid coolant through non-rotating portions of the motor stator and then through heat exchangers cooled in part by air which has flowed through the rotating portions of the motor rotor. The drag reduction portion and the cooled electric motor portion may share the same inlet.

A propulsion system for an aircraft includes an electric propulsion engine configured to be mounted to the aircraft at an aft end of the aircraft. The electric propulsion engine includes a power gearbox mechanically coupled to an electric motor. The electric propulsion engine further includes a fan rotatable about a central axis of the electric propulsion engine by the electric motor through the power gearbox. Moreover, the electric propulsion engine includes an attachment assembly for mounting at least one of the electric motor or the power gearbox. The attachment assembly includes a torsional damper for accommodating a torsional vibration of the electric motor or the power gearbox.

Flow multiplier systems for aircraft are described herein. A flow multiplier system includes a turbo-compressor having a compressor, a turbine, and a drive shaft coupled between the compressor and the turbine. A compressor outlet of the compressor is fluidly coupled to an ejector in a gas turbine engine. The system also includes a supply line fluidly coupling a compressed air tank and a turbine inlet and a valve coupled to the supply line. The system includes a controller configured to, based on an input signal requesting to increase output power of the gas turbine engine, send a command signal to open the valve to enable a flow of pressurized air from the compressed air tank to the turbine inlet. The turbine drives the compressor to create high pressure air at the compressor outlet, which is provided into the gas turbine engine to increase the output power.

A vertical take-off and landing aircraft, and a control method for the aircraft, are disclosed. The aircraft has a vertical motion mode and a forward thrust mode. The aircraft comprises an airframe, having a wing section; a forward thrust means, for use during the forward thrust mode; a vertical lift rotor system, the rotor system being housed in a portion of the airframe; and a rotor control component configured to, during forward thrust, actuate the rotor system to modify the aerodynamic flow around the portion of the airframe housing the rotor system. Forward thrust may occur during the forward thrust mode, or other flight modes, such as transition phases to/from vertical motion and forward thrust modes. Modification of the aerodynamic flow may be used to optimize the aerodynamic flow around the portion of the airframe housing the rotor system.

An air injection assembly for an aircraft is provided. The aircraft includes a fuselage extending between a forward end and an aft end along a longitudinal direction and a boundary layer ingestion fan mounted to the fuselage at the aft end of the fuselage. The air injection assembly includes a plurality of injection ports defined on a surface of the fuselage at a location upstream of the boundary layer ingestion fan. A supplemental airflow is provided through a fluid passageway to the injection ports where it is ejected to displace at least a portion of relatively higher velocity boundary layer airflow. In this manner, the airflow entering boundary layer ingestion fan is more uniform, has less swirl distortion, and has a lower average velocity.

An aircraft structure, for example a wing, including a skin. The skin has an external surface, on an outer face of the skin. The skin has an internal surface, located opposite the external surface on an inner face of the skin. The aircraft structure includes a laminar flow control system including a compressor. The aircraft structure is so arranged that the exhaust air from the compressor is directed onto the internal surface of the skin of the aircraft structure, for example thus providing hot exhaust air which function as an ice protection system (whether by de-icing or anti-icing). A method of providing ice protection on a surface of an aircraft using exhaust air from a laminar flow control compressor is also described.

A propulsion system for an aircraft includes an electric propulsion engine configured to be mounted to the aircraft at an aft end of the aircraft. The electric propulsion engine includes a power gearbox mechanically coupled to an electric motor. The electric propulsion engine further includes a fan rotatable about a central axis of the electric propulsion engine by the electric motor through the power gearbox. Moreover, the electric propulsion engine includes an attachment assembly for mounting at least one of the electric motor or the power gearbox. The attachment assembly includes a torsional damper for accommodating a torsional vibration of the electric motor or the power gearbox.

An aircraft includes a fuselage and a wing assembly attached to or formed integrally with the fuselage. The aircraft also includes a propulsion system having a port propulsor and a starboard propulsor. The port and starboard propulsors are each attached to the wing assembly on opposing sides of the fuselage and are rotatable between a forward thrust position and a vertical thrust position. The propulsion system also includes a supplemental propulsor mounted to the fuselage to provide certain efficiencies for the aircraft.

Fluid systems are described herein. An example embodiment of a fluid system has a first body portion, a second body portion, a plurality of supports, a plurality of fluid pressurizers, and a plurality of ducts. The first body portion and the second body portion cooperatively define an injection opening, a suction opening, and a channel that extends from the injection opening to the suction opening. The fluid pressurizer is disposed within the channel cooperatively defined by the first body portion and the second body portion. Each duct of the plurality of ducts is disposed within the channel cooperatively defined by the first body portion and the second body portion.

An aircraft includes a fuselage and at least one primary wing having an upper surface, at least one recess in the upper surface and at least one conduit in fluid communication with the at least one recess. At least one ejector is disposed within the at least one recess and is configured to receive compressed air via the at least one conduit.