A propulsion system for an aircraft includes at least one gas turbine engine, an electric auxiliary fan driving motor configured to selectively receive electric power input from one or more electric power sources, and at least one auxiliary propulsion fan configured to selectively receive a motive force from either or both of the at least one gas turbine engine and the electric auxiliary fan driving motor. The propulsion system also includes a controller configured to establish a plurality of takeoff thrust settings of the at least one gas turbine engine and the electric auxiliary fan driving motor such that a minimum total aircraft thrust required for takeoff of the aircraft is produced.

The present disclosure is directed to a fan section positioned on a tail section of an aircraft, in which the fan section defines a circumferential direction, a radial direction, and an axial direction. The fan section includes a fan and a nacelle. The fan includes a plurality of fan blades and a fan shaft, in which the plurality of fan blades are rotatable with the shaft. The nacelle includes a wall at least partially enclosing the fan. The wall includes a first portion and a second portion. The first portion translates relative to the second portion between a first, closed position in which the wall of the nacelle circumferentially encloses the fan and a second, open position in which at least a portion of the fan is unenclosed by the wall of the nacelle.

A tandem fan for a boundary layer ingestion engine is disclosed. In various embodiments, the tandem fan includes a fan disk configured for rotation about a longitudinal axis; a primary fan blade extending radially from the fan disk, the primary fan blade having a primary fan blade span; and a secondary fan blade extending radially from the fan disk, the secondary fan blade having a secondary fan blade span within about ninety percent to about one-hundred percent of the primary fan blade span.

An aircraft includes an airframe, an engine mounted to the airframe, and an engine inlet for receiving an ambient airflow and providing the ambient airflow to the engine. An amount of airflow provided to the engine inlet is controllable.

An aircraft including an aft-mounted boundary layer energisation system is shown. The system comprises a nacelle arranged around a tailcone of the aircraft which thereby defines a duct, the duct having, in axial flow series, an intake, a heat exchanger, and a nozzle, and no turbomachinery therein, whereby the system energises a boundary layer of the aircraft by means of Meredith effect.

A propulsion system for an aircraft including a fuselage and a wing assembly. The propulsion system includes a first propulsion device at the level of the rear part of the fuselage and constituted of at least one BLI propulsion unit including a fan, a second propulsion device constituted of at least one conventional propulsion unit, and a transmission device coupling the first and second propulsion devices. The second propulsion system therefore generates the energy necessary for driving in rotation the fan of the BLI propulsion unit or units. The thrust produced by the propulsion devices contributes to generating the total thrust of the aircraft. In this propulsion system at least one conventional propulsion unit constituting the second propulsion device is situated on one side of the rear part of the fuselage between the tail of the fuselage and the wing assembly of the aircraft.

An axial flux electrical machine comprises a first flux generating assembly, a second flux generating assembly, a shaft and a speed controller. The shaft has an axis of rotation. Each of the first flux generating assembly and the second flux generating assembly is rotationally located on the shaft in axial juxtaposition to one another, with the first flux generating assembly being axially separated from the second flux generating assembly by a separation distance. The speed controller is configured to modify a magnetic field generated by either of the first flux generating assembly and the second flux generating assembly so as to control a rotational speed of the electrical machine.

An aircraft is provided and includes fuselage having a nose, a main section aft of the nose and a tail aft of the main section, an engine nacelle partially embedded in the tail and including a boundary layer ingestion (BLI) propulsor with an inlet directly adjacent to the fuselage and a nozzle element disposed upstream from the inlet and configured to accelerate boundary flows flowing toward the interior side of the engine nacelle.

An engine assembly with an electric motor that includes a cooling system of which a heat sink portion is arranged in an exhaust cone downstream of the fan driven by the electric motor, that is designed to effect thermal exchanges with a wall of the exhaust cone. Such an electric rear fan arrangement with boundary layer ingestion enables a cold air flow coming from the fan when the engine assembly is in operation to be used to cool the different components of the engine assembly.

An aircraft includes an aircraft heat source; a propulsion system including an electric propulsion engine, the electric propulsion engine including an electric motor and a fan rotatable by the electric motor, the electric propulsion engine further defining a fan air flowpath; a thermal management system including a heat source exchanger in thermal communication with the aircraft heat source, a heat sink exchanger in thermal communication with the fan air flowpath of the electric propulsion engine, and a thermal distribution bus extending from the heat source exchanger to the heat sink exchanger; and a control system operably connected to the thermal management system for selectively thermally coupling the heat sink exchanger with the heat source exchanger.