A flow path duct system for a propulsion system of an aircraft includes a base defining a flow surface. The base has an internal surface and an external surface. A plurality of perforations are formed through the base between the internal surface and the external surface. A plurality of supports define a plurality of cavities. The plurality of supports extend outwardly from the external surface of the of the base. One or more of the plurality of cavities are in fluid communication with the one or more of the plurality of perforations. A backing surface is secured to the plurality of supports. The plurality of supports are disposed between the base and the backing surface. The one or more of the plurality of cavities are in fluid communication with an internal volume defined by the internal surface of the base through the one or more of the plurality of perforations. The base, the plurality of supports, and the backing surface can be integrally formed together as a monolithic, load-bearing structure.

A compact inlet design including a single bulkhead and/or an acoustic panel extending into nacelle lip region for noise reduction.

An acoustic panel including a first face sheet having a plurality of openings; a core attached to the face sheet, the core comprising a plurality of cells each having cell walls; and a plurality of noise attenuating features each comprising at least one of the openings in combination with one of the cells, wherein the openings are disposed away from the cell walls so that the noise attenuating features suppress the transmission of acoustic waves in acoustic communication with the openings.

A nacelle inlet may comprise an aft bulkhead, an attachment ring extending in an aft direction from the aft bulkhead, an acoustic liner disposed radially inward from the attachment ring, the acoustic liner comprising a proximal skin, a distal skin, and a core disposed between the proximal skin and the distal skin, and a shroud extending longitudinally between a forward side of the shroud and an aft side of the shroud and extending circumferentially between a first end of the shroud and a second end of the shroud, wherein the shroud defines a plenum disposed between the acoustic liner and the shroud, the plenum is in fluid communication with the core via perforations in the distal skin. The plenum may serve to attenuate low frequency noise known as “buzz saw” tones and/or alleviate pressure resonance conditions that may cause structural damage to the engine fan blades.

An acoustic attenuation panel for a propulsion unit including a nacelle and a turbojet engine includes a cellular core disposed between an inner skin and an outer skin, called acoustic skin, the acoustic skin including a plurality of acoustic apertures, the acoustic apertures being inclined, at a non-zero inclination angle (β) relative to the direction normal to the acoustic skin, upstream with respect to the flow direction of the air or gas flow to which the panel is intended to be subjected under normal operating conditions, that is to say upstream of the propulsion unit when the panel is mounted in such a unit.

A frost protection system for an aircraft engine nacelle, the nacelle comprising an inner shroud provided with at least one acoustic panel and an air intake lip forming a leading edge of the nacelle. The protection system comprises a heat exchanger device including at least one heat pipe configured to transfer heat emitted by a heat source to the at least one acoustic panel.

The invention relates to acoustic management, on an aircraft turbomachine (3,12) or on a nacelle (1,10), via a panel (30,32). On a support (38) is reserved a recess (34), recessed with respect to a surrounding general surface (36) for contact with moving air. The recess (34) is adapted to receive the panel, as another so-called surface for contact with moving air. The support (38) and/or the panel comprise removable connecting elements for, in the recess (34), mounting it removably with respect to the support, the panel being an acoustic panel or a non-acoustic panel.

An aircraft having a static air inlet system. The static air inlet system comprises a static air intake, the static air intake having a through opening formed in a top structural assembly, the through opening forming an interface between a medium and an inside space of the top structural assembly. The static air inlet system has at least one separator subdividing the through opening into at least two distinct slots, the separator comprising a first portion extended by a second portion, the first portion extending inside the inside space and the second portion extending outside the inside space.

An assembly method for an air intake of a jet engine of an aircraft, comprising providing an acoustic panel, an outside panel, flanges and a collar, arranging a rear edge of the acoustic panel on an assembly chassis. The flanges and the collar are attached at the rear edge of the acoustic panel. A rear edge of the outside panel is attached to the attached collar. A first set of geometric data of a front edge of the acoustic panel is measured and a second set of geometric data of a front edge of the outside panel is measured. A U-shaped lip as a single element is produced based on the two sets of geometric data. An inside leg of the lip is attached to the front edge of the acoustic panel and an outside leg of the lip is attached to the front edge of the outside panel.

A sound attenuation panel that includes an incident wall and a frame unit connected to the incident wall. The incident wall defines an aperture therethrough. The frame unit includes multiple spoke members spaced apart from one another and radially extending from one or more central hub openings of the frame unit. The one or more central hub openings align with the aperture of the incident wall. The frame unit defines channels between adjacent pairs of the spoke members. The channels fluidly connect to the one or more central hub openings. The frame unit is configured to receive sound waves into the central hub opening through the aperture of the incident wall to dissipate the sound waves through the channels between the spoke members.