Disclosed is an electrically driven ducted fan engine, comprising a housing with an inner housing wall, defining a substantially cylindrical inner space and a longitudinal axis, an inlet opening, a rotor with a multitude of rotor blades positioned in the inner space of the housing downstream of the inlet opening, a stator assembly with a multitude of guide vanes extending from a radially central region of the inner space to the inner wall of the housing, and an exhaust opening provided in the housing downstream of the stator assembly, an interstage region defined between the rotor and the stator assembly, a guide vane region defined in which guide vanes extend to the inner wall of the housing and an exhaust section, wherein in at least one of the interstage region, the guide vane region and the exhaust region, acoustic liners are provided to the housing.

A method for dehumidifying a perforated acoustic skin includes disposing a sheet of material over a perforated acoustic skin, sealing a periphery of the sheet of material to the perforated acoustic skin to form a cavity between the sheet of material and the perforated acoustic skin, disposing at least one dehumidifier in fluid communication with the cavity, and activating the dehumidifier to remove moist air from a core of the perforated acoustic skin. The dehumidifier(s) may be mounted to the sheet of material.

A blended wing body aircraft includes a body section having an aerodynamic lifting surface. The body section includes an upper body and a lower body. The blended wing body aircraft also includes a plurality of blended wing sections further defining the body section. The blended wing body aircraft includes one or more grooves in the body section. The one or more grooves extend from the upper body towards the lower body. The blended wing body aircraft further includes one or more open-fan engines mounted at least partially within the one or more grooves. The one or more open-fan engines ingest a portion of a boundary layer of the blended wing body aircraft.

An acoustic panel including first and second cellular structures, the first cellular structure including a set-back portion to form a recess dimensioned to accommodate the second cellular structure such that first faces of the first and second cellular structures, in contact with a first, acoustically resistive layer, are coplanar and that first edge faces of the first and second cellular structures are coplanar when the second edge face of the second cellular structure is in contact with the set-back portion. By virtue of the set-back portion, the first and second cellular structures are positioned correctly with respect to one another, thus contributing to an optimization of the acoustic treatment.

Propulsion assembly for an aircraft, comprising a fuselage extending along a longitudinal axis and enclosing an inner enclosure, at least one ducted engine fixed to the fuselage and comprising an air inlet section, the air inlet section being disposed at least partly in the inner enclosure, at least one plenum chamber disposed in the inner enclosure upstream of the air inlet section and in fluid communication with said air inlet section, at least one air intake formed on an outer wall of the fuselage, the inlet of the air intake being partly delimited by said outer wall of the fuselage, the air intake being configured to ingest external air and deflect it towards the plenum chamber.

A method for manufacturing an acoustic element of a sound absorption structure including at least one cylindrical, conical or truncated conical chamber obtained from a flat preform shaped and then assembled in order to obtain the cylindrical, conical or truncated conical shape of the chamber. This manufacturing method makes it possible to obtain an acoustic element that has thin walls and is made from a material suited to its environment. An acoustic element obtained using the manufacturing method, a sound absorption structure comprising at least one such acoustic element and an aircraft powerplant comprising at least one such structure are also described.

An acoustic panel for an aircraft nacelle includes, from a central axis of the nacelle to the exterior thereof, a resistive skin perforated with sound-absorbing micro-perforations, a first attenuation stage, a septum perforated with holes, a second attenuation stage, and a back skin configured to provide the mechanical strength of the acoustic panel. The septum is a planar wall having a thickness greater than that of the resistive skin, preferably greater than 4 mm. Such a panel is configured to attenuate several frequency ranges one of which being a low-frequency range, while optimizing the weight, the cost and the air intake functions. The thickness of the septum, the dimensions of the holes in the septum, the OAR of the septum and the height of the second attenuation stage are adjusted to match the mean attenuated low frequency to the vibration frequency of the aircraft engine.

A method for manufacturing a porous layer of an acoustic attenuation structure, porous layer of an acoustic attenuation structure thus obtained and acoustic attenuation structure comprising the porous layer. A method for manufacturing a porous layer of an acoustic attenuation structure includes a first step of production of a solid layer including at least one structural frame embedded in a resin matrix and having first and second reinforcing strips arranged so as to delimit zones without reinforcing strips and a second step of production of through-holes in the zones without reinforcing strips of the solid layer using a laser beam.

A gas turbine engine includes a fan case assembly adapted to extend around blades of a fan rotor included in the gas turbine engine. The fan case assembly includes an annular case that extends around an axis, an acoustic panel coupled to the annular case and configured to dampen vibrations and a bolting arrangement that couples the acoustic panel to the annular case.

An acoustic damper has a sound pickup unit defining a plurality of pickup unit passageways. Hollow flexible tubes are connected to exit openings of the pickup unit passageways and extend outwardly therefrom. The hollow flexible tubes and pickup unit passageways define acoustic paths.