A gas turbine engine, has: a case extending circumferentially around a central axis of the gas turbine engine; a boss protruding from the case away from the central axis, the boss defining an internal passage; a tubular member received within the internal passage of the boss and secured to the boss; an annular gap extending all around the tubular member and located between the tubular member and the boss; and a fitting hydraulically connecting a fluid source to the tubular member, the fitting having a portion received within the tubular member and encircled by both of the annular gap and the tubular member, the fitting sealingly engaged to the tubular member.

A turbofan gas turbine engine includes a core engine within a core nacelle, a fan nacelle at least partially surrounding the core nacelle to define a bypass flow path and a variable fan nozzle exit area for bypass flow, and a pylon variable area flow system which operates to effect the bypass flow. A method of operating a turbofan gas turbine engine is also disclosed.

A turbofan engine including: a turbine shaft; a fan shaft; and a reduction mechanism coupling the turbine shaft and the fan shaft, is provided. The turbofan engine has a bypass ratio greater than or equal to 10, and the turbine shaft is supported by four bearings such that the flexural deformation modes of the turbine shaft are positioned in transient phase or outside the operating range of the turbofan engine.

A gas turbine engine includes a core engine defined about an axis, a gear system driven by the core engine, and a pylon variable area flow system. A fan is driven by the gear system. The variable area flow system operates to effect the bypass flow.

A nacelle for a turbomachine is provided and includes an inner wall that is annular about a longitudinal axis of the nacelle, the annular inner wall being designed to surround part of the turbomachine. The nacelle further includes an annular outer wall surrounding the annular inner wall. The annular outer wall includes a first acoustically porous part, and the annular inner wall including a second acoustically porous part. The first and second porous parts are arranged facing one another so as to allow soundwaves, emitted by the turbomachine housed in the nacelle, to pass through the annular inner wall and then the annular outer wall so as to escape from the nacelle.

A jet engine which includes: a fan with a plurality of stages of rotor blades; a compressor compressing air sent from the fan; a combustor generating combustion gas by using compressed air generated by the compressor; a turbine generating a driving force from the combustion gas; a nozzle discharging the combustion gas; a variable guide vane disposed upstream of the rotor blades of a second and later stage of the rotor blades of the fan and adjusts an inlet angle of air flow against the second and later stage of the rotor blades; a fluid resistance adjusting device adjusting a fluid resistance at the nozzle; and a controller which controlling the variable guide vane such that the inlet angle at the time of cruise flight is smaller than the inlet angle at the time of acceleration.

An aircraft extending between a forward end and an aft end is provided. The aircraft includes an auxiliary power unit positioned proximate the aft end of the aircraft, the auxiliary power unit having an auxiliary power unit inlet duct and an auxiliary power unit exhaust duct, and a boundary layer ingestion fan positioned proximate the aft end of the aircraft, the boundary layer ingestion fan having a support shaft, wherein the auxiliary power unit exhaust duct extends through a portion of the support shaft of the boundary layer ingestion fan.

A fan system includes a rotor having plurality of blades and a ring airfoil, the plurality of blades being rotatably joined to a hub and the ring airfoil. The fan system may include a second contra-rotationally disposed rotor having a plurality of blades and a ring airfoil. The first and second ring airfoils having a cambered shape and an angle of attack between about 5 degrees and about 45 degrees. Passive leading edge slats are attached to the ring airfoil and are configured to open and close using springs.

An active device for attenuating the acoustic emissions of an aircraft turbojet engine includes circulation conduits for a pressurized air flow rate supplying rotary elements each having a pulsation system for the delivered air. The rotary elements are controlled in amplitude and phase and deliver, to outlet diffusers, a pulsed air flow rate with a pulsation at the frequency of the noise to be attenuated having an amplitude and a phase adjusted according to a local feedback law with microphones to attenuate the radiated acoustic power.

The present disclosure is directed to a turbine engine (10) defining an axial direction and a radial direction. The turbine engine includes a fan or propeller assembly (14) comprising a gearbox; an engine core (20) comprising one or more rotors, wherein at least one of the rotors defines an axially extended annular hub; and a flexible coupling shaft (100) defining a first end and a second end along the axial direction, wherein the first end is connected to the engine core and the second end is connected to the gearbox, and further wherein the flexible coupling shaft extends from the one or more rotors to the gearbox in the axial direction and inward of the hub in the radial direction.