A method of making an impeller includes building the impeller in a layer by layer process in a build direction along the rotational axis starting from a base of the hub. The plurality of blades includes a plurality of perforated blades that support the shroud during additively manufacturing the impeller. The method can include installing the impeller in a fuel pump, air compressor, or the like, without removing the perforated blades from the impeller.

A method of making an impeller includes building the impeller in a layer by layer process in a build direction along the rotational axis starting from a base of the hub. The plurality of blades includes a plurality of perforated blades that support the shroud during additively manufacturing the impeller. The method can include installing the impeller in a fuel pump, air compressor, or the like, without removing the perforated blades from the impeller.

Aircraft power plants including combustion engines, and associated methods for recuperating waste heat from such aircraft power plants are described. A method includes transferring the heat rejected by the internal combustion engine to supercritical CO.sub.2 (sCO.sub.2) used as a working fluid in a heat engine. The heat engine converts at least some the heat transferred to the sCO.sub.2 to mechanical energy to perform useful work onboard the aircraft.

A turbine engine includes integrated electric machines in the compressor section and the turbine section to supplement power produced from fuel with electric power. The example compressor section includes a compressor electric motor that is coupled to a compressor generator. The example turbine section includes a turbine electric motor that is coupled to the geared architecture to supplement power driving the fan section. A turbine generator provides electric power to the turbine electric motor.

A boundary layer ingestion fan system for location aft of the fuselage of an aircraft is shown. It comprises a nacelle defining a duct, and a fan located within the duct. The fan comprises a hub arranged to rotate around a rotational axis and a plurality of blades attached to the hub, each of which has a span from a root at the hub defining a 0 percent span position (r.sub.hub) to a tip defining a 100 percent span position (r.sub.tip) and a plurality of span positions therebetween (r∈[r.sub.hub, r.sub.tip]). The hub has a negative hade angle (γ) with respect to the rotational axis at an axial position coincident with the leading edge of the blades.

A boundary layer ingestion fan system for location aft of the fuselage of an aircraft is shown. It comprises a nacelle defining a duct, and a fan located within the duct. The fan comprises a hub arranged to rotate around a rotational axis and a plurality of blades attached to the hub, each of which has a span from a root at the hub defining a 0 percent span position (r.sub.hub) to a tip defining a 100 percent span position (r.sub.tip) and a plurality of span positions therebetween (r∈[r.sub.hub, r.sub.tip]). A plurality of outlet guide vanes are positioned aft of the fan. An afterbody is located aft of the plurality of outlet guide vanes and which tapers to an apex having an apex angle with respect to the rotational axis of between 35 and 45 degrees.

Hybrid propulsion is obtained by arranging, around a conventional turbomachine, a reversible electric machine linked to the low-pressure shaft via a mechanical movement transmission, a one-way clutch being arranged on the low-pressure shaft between the fan and a low-pressure compressor. The low-pressure shaft includes two aligned portions which can be separated and reconnected. A casing includes a first portion able to tilt around a horizontal transverse axis of the aircraft relative to a second portions of the casing. One portion of the low-pressure shaft, the fan and the reversible electric machine are mounted on the first portion of the casing, and the other portion of the low-pressure shaft is mounted on the second portion of the casing. This device facilitates electric taxiing of the aircraft, using the machine as a motor, whereas the rear of the low-pressure shaft remains stationary.

A hybrid electric gas turbine engine system includes a first compressor and an auxiliary compressor. The first compressor is configured to output first compressed air. The auxiliary compressor is configured to operate in parallel with the first compressor to output second compressed air. A controller is configured to selectively activate the first compressor or the auxiliary compressor based on an operating condition of the hybrid electric gas turbine engine system.

A hybrid electric gas turbine engine system includes a first compressor and an auxiliary compressor. The first compressor is configured to output first compressed air. The auxiliary compressor is configured to operate in parallel with the first compressor to output second compressed air. A controller is configured to selectively activate the first compressor or the auxiliary compressor based on an operating condition of the hybrid electric gas turbine engine system.

The invention relates to a planetary gear reducer (21) for an aircraft turbine engine (1), the reducer (21) comprising a sun gear (30) and a ring gear (33) which are centred on a longitudinal axis X and a planet carrier (32) which carries at least one planet gear (31) rotatably mounted about a planet axis A parallel to the longitudinal axis X, the sun gear (30) being rotatable about the longitudinal axis, the planet gear (31) meshing both with the sun gear (30) and the ring gear (33), the planet carrier (32) being movable about the longitudinal axis and the ring gear (33) being rotationally fixed. According to the invention, the reducer (21) comprises an electric machine (50) integrated therewith and which comprises a rotor (51) mounted on the planet carrier (32) in such a way as to be rotated about the longitudinal axis X and a stator (52) mounted on the ring gear (33).