An air intake of a turbojet engine nacelle includes an air intake lip, an annular structure, a rear partition, and at least one acoustic attenuation structure. The annular structure includes at least a part of an outer fairing and an inner fairing joined to each other by the air intake lip. The rear partition is connected to the inner fairing. The acoustic attenuation structure is attached to the inner fairing of the annular structure. At least part of the outer fairing, the air intake lip and the inner fairing are integral with each other.

A method is provided for forming a structured panel. During this method, a cellular core is formed that comprises a corrugated ribbon configured with a plurality of baffles and a plurality of septums. Each of the septums extends longitudinally between and connected to a respective adjacent pair of the baffles. At least one element of the corrugated ribbon includes a structural reinforcement. The forming includes: feeding a ribbon of material between a first roller and a second roller, corrugating the ribbon of material with the first roller and the second roller to provide the baffles and the septums, and stamping the structural reinforcement into the element with the first roller and the second roller. The cellular core is bonded to a first skin. The cellular core is bonded to a second skin. The cellular core is vertically between the first skin and the second skin, and the first skin is configured with a plurality of perforations.

An acoustic attenuation panel includes a perforated acoustic wall, a first honeycomb structure coupled to the perforated acoustic wall and including a plurality of acoustic cells defined by peripheral partitions, a second honeycomb structure including a plurality of acoustic cells defined by peripheral partitions, and a septum which includes a plurality of macro-perforations and is positioned between the first honeycomb structure and the second honeycomb structure. Each acoustic cell of the first honeycomb structure and each acoustic cell of the at least second honeycomb structure are arranged opposite a single perforation of the septum.

Methods for reworking structures and reworked cellular core panels, reworked structures comprising the reworked cellular core panels, and guides and cutting apparatuses for reworking cellular acoustic panels and reworking cellular acoustic and non-acoustic panels are disclosed.

An inlet for use with a nacelle having an axis includes an outer barrel. The inlet further includes a lip skin defining a plurality of elongated exit holes including a first circumferential outer hole, a second circumferential outer hole, and a plurality of center holes located between the first circumferential outer hole and the second circumferential outer hole, the first circumferential outer hole being located at least 10 degrees of an entire circumference of the inlet away from the second circumferential outer hole.

A method for manufacturing a sound attenuating panel uses an alveolar-core structure including a first edge and a second edge separated by alveolar cells, the alveolar cells including walls extending from the first and second edges and defining a primary conduit for the circulation of a sound wave that is to be attenuated. The method includes covering the first edge or the second edge of the alveolar-core structure with a compartmentation wall; deforming the compartmentation wall to define at least one secondary conduit for the circulation of a sound wave that is to be attenuated, the secondary conduit extending at least partially within said primary conduit; and creating an opening in the compartmentation wall to permit communication between the primary and secondary conduits.

A sandwich panel for an aircraft turbojet nacelle includes an outer skin in contact with an air flow, an inner skin opposed to the outer skin, and an intermediate system comprising partitions connecting the inner and outer skins so as to form cells, the inner skin of at least one cell having at least one corrugation configured to allow the materials making up the sandwich panel to deform in the event of thermal variation.

A method for producing an alveolar soundproofing structure in which a portion of a membrane of a diaphragm including an acoustic outlet is inserted into a hole of a perforated membrane which covers a cell of the alveolar structure, and the diaphragm is pressed into the cell with the perforated membrane becoming deformed and is fixed at that location. It also relates to the alveolar structure. Such a method enables different types of diaphragms to be inserted into different configurations of cells and enables the diaphragm to be fixed therein, in accordance with the sound frequencies to be processed.

A cellular sound insulation structure and associated aircraft, a cell of which is provided with a diaphragm which includes a membrane having at least one orifice passing through a thickness of the membrane, and at least one tube surmounting the orifice and extending from a face of the membrane into one compartment of the cell, the tube comprising a free end, forming an acoustic outlet, which is positioned at a distance (p) from the base cross section of the cell. Also, a method for manufacturing such a cellular sound insulation structure, as well as to a tool for inserting a diaphragm into a cell. Such a cellular structure makes it possible to treat a wider acoustic frequency spectrum, and its acoustic dimensioning as well as its manufacture are simplified.

An acoustic panel is provided that includes a perforated first skin, a second skin and a corrugated structure. The corrugated structure is between and is connected to the perforated first skin and the second skin. The corrugated structure includes a first baffle, a first septum, first material and second material that is configured with the first material. The first baffle is formed by an uninterrupted portion of the first material. The first septum is formed by a portion of the second material that is exposed through an interruption in the first material.