Abstract: An acoustic panel comprising a cellular structure, such as a honeycomb structure, having cells that open at least onto a first frontal face of the structure. The panel comprises a capsular skin which is fastened to the first frontal face of the cellular structure next to a plurality of cells. The capsular skin including a continuous layer of material, in one piece, forming capsules that extend into the cellular structure. At least one channel is provided at the apex of each capsule for the passage of acoustic waves. Such a panel effectively attenuates the noise of aircraft engines, in particular, the low frequencies. It is extremely easy to manufacture industrially, the capsular skin being able to be obtained by molding with polymerization in situ, the polymerizable material then adhering to the cellular structure while it polymerizes.

Abstract: 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.

Abstract: A turbofan engine with a nacelle and a flow path, in which the nacelle comprises a movable cowl that makes it possible to define a window between the flow path and the outside, veils with a first edge fixed to the movable cowl and alternately assuming a folded position or a deployed position across the flow path, and a pneumatic system displacing a second edge of the veils from the folded position to the deployed position and vice versa. The pneumatic system comprises a rigid main roll, for each veil, at least one extendable secondary roll fixed to a second edge of the veil, and a pressurization and depressurization system which, alternately, generates a pressure or a depression in each secondary roll. Replacing the reverse doors and their driving mechanisms with flexible veils and a pneumatic system allows for a weight reduction.

Abstract: 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.

Abstract: A method for manufacturing two soundproof panels of an aircraft nacelle including a duct. The manufacturing method includes a step of supplying a mold having, on a single face, a cavity for each soundproof panel, a step of producing, in the bottom of each cavity, an inner skin for being oriented towards the duct, and a curing step during which the elements present in the mold are cured in the mold. Such a method makes it possible to produce the two soundproof panels in the same mold, thus reducing the gaps between them after they have been positioned.

Abstract: An aircraft engine nacelle comprising an icing protection system and an icing protection method for such an aircraft engine nacelle. The aircraft engine nacelle comprises an air inlet comprising a lip, a tubular air inlet piece and an icing protection system. The icing protection system comprises an icing prevention means powered continuously by a first electrical energy source and wholly or partly covering the lip, a de-icing means powered by a second electrical energy source covering the tubular air inlet piece and a controller configured to acquire a current total air temperature value, and control the second electrical energy source as a function of the current total air temperature value.

Abstract: A sound-absorbing panel includes: an inner skin traversed by holes and intended to be oriented towards a channel in which a fluid flows, a heating mat formed by strips fixed to the inner skin on the side opposite to the channel and oriented in a first direction, wherein two adjacent strips are distant from each other in order to define a slot between them, a base fixed to the strips on the side opposite to the inner skin, wherein the base includes, on the strips side, grooves extending in a second direction different from the first direction and wherein the base has, between two successive grooves, a rib, a cellular core fixed to the base on the side opposite to the strips, and an outer panel fixed to the cellular core on the side opposite to the base.

Abstract: A nacelle of an aircraft propulsion assembly includes a front section and a main section. The nacelle also includes a junction flange between the front section and the main section including a plurality of deformable damper elements distributed along the inner peripheral edge of a stiffening frame of the nacelle. The damper element allows significant stresses to be absorbed between the engine flange and the stiffening frame. This configuration is particularly adapted to large nacelles. An aircraft propulsion assembly including such a nacelle is also described.

Abstract: An anterior part of a nacelle of a propulsion assembly of an aircraft, having an air intake lip and a front frame disposed at the rear of the air intake lip that connects an outer part to an inner part of the air intake lip. A de-icing duct is formed in front of the front frame. The front frame is shaped so that the de-icing duct has a main cavity and a thermal transition region formed behind the main cavity between an internal face of the outer part of the air intake lip and the front frame. The thermal transition region extends over a longitudinal dimension greater than its average radial dimension, the front frame forming, with respect to the internal face of the outer part of the air intake lip, an angle, measured longitudinally, of between ?20° and +10° over the majority of the thermal transition region.

Abstract: An aircraft nacelle air intake includes sectors each having a lip forming portion, an outer panel forming portion and an inner panel forming portion. The outer panel forming portions and lip forming portions are formed by a continuous one-piece wall. At at least one junction between two adjacent sectors, an opening and a hatch are provided between the outer panel forming portions of the sectors. The inner panel forming portions and the lip forming portions of the sectors are edge to edge and fixed to each other by fixing devices accessible from the inside of the sectors and invisible from outside of the sectors. A maintenance method in which, when a zone of a sector is damaged, the sector concerned is removed as a whole and is replaced by a new of “recycled” sector is also described.

Abstract: An anterior part of an aircraft propulsion assembly nacelle, having an air intake lip disposed at a front end and an outer panel, of which an outer face extends an outer part of the air intake lip. A front edge of the outer panel and a rear edge of the air intake lip are shaped so as to overlap radially and to nest so as to ensure a continuous surface between the outer surface of the outer part of the air intake lip and the outer face of the outer panel. Moreover, the front edge of the outer panel is connected to the rear edge of the air intake lip with no added rigid element. This permits a rigid connection while avoiding creating local irregularities on the outer surface of the nacelle, which irregularities might disrupt the flow of air around the nacelle, giving rise to additional drag.

Abstract: An acoustic panel for an aircraft nacelle air intake comprising a resistive skin perforated by noise absorption holes and a core against which the resistive skin extends, wherein the resistive skin has a smooth visible face and a castellated rear face with alternating ribs and grooves. The noise absorption holes are formed exclusively in the grooves, i.e., in a zone where the skin is less thick, which enables the holes to have a diameter that is both greater than the thickness of the skin and small enough not to have any impact on drag. The mechanical strength of the resistive skin provided by the ribs ensures that the lesser thickness of the resistive skin in the grooves does not render the resistive skin overly flexible.

Abstract: A forward part of an aircraft propulsion unit nacelle, comprising an air intake lip, an acoustic panel, and a rigid connection between the acoustic panel and the air intake lip. The acoustic panel has a resistive surface and a back skin, and the rigid connection is formed between the air intake lip and the back skin of the acoustic panel to form a propagation path for forces between the air intake lip and the back skin. This configuration gives freedom from design constraints, which enables an increase in the acoustic treatment region toward the front of the nacelle. An aircraft propulsion unit comprising a nacelle having such a forward part is also provided.

Abstract: An anti-icing protection system for an aircraft engine nacelle, the nacelle comprising an inner shroud, an air intake lip forming a leading edge of the nacelle, the protection system comprising a heat exchanger device including at least one heat pipe configured to transfer heat emitted by a heat source to the inner shroud.

Abstract: An optimized protection against ice on the inner and outer faces of an aircraft engine nacelle air intake with the air intake including an outer face and an inner face meeting at a line at the longitudinally extreme, called extremum line, an acoustic panel being installed on the inner surface of a part of the inner face. An elimination system based on vibration of the ice formed is put in place on at least a part of the outer face and an ice formation prevention system using a hot fluid is put in place on at least a part of the inner face and either an ice elimination system or an ice formation prevention system using a hot fluid is installed on the inner face and on the outer face, a marking line marking the boundary between the two systems.

Abstract: An anti-icing protection system for an aircraft engine nacelle, the nacelle comprising an inner shroud provided with at least one acoustic panel, an air intake lip forming a leading edge of the nacelle, the protection system comprising a heat exchanger device including at least one heat pipe configured to transfer heat emitted by a heat source to the acoustic panel or panels.

Abstract: Sound attenuation panel for aircraft having a combination of acoustic attenuation properties. The acoustic panel includes an acoustic structure having a cellular structure and a resistive skin and a backing skin, the acoustic panel also including at least one auxiliary acoustic device with cavities that is configured to produce additional acoustic absorption, the auxiliary acoustic device with cavities being attached to the acoustic structure and including adjacent chambers or cavities separated by shared walls, each of the chambers or cavities having perforations and being adapted to produce acoustic absorption. The combination of the acoustic structure and the auxiliary acoustic device with cavities enables combination of the acoustic absorption properties of these two types of element and an increased range of frequencies of the noise that can be attenuated by the acoustic panel without increasing its overall size.

Abstract: An optimized protection against ice on the inner and outer faces of an aircraft engine nacelle air intake with the air intake including an outer face and an inner face meeting at a line at the longitudinally extreme, called extremum line, an acoustic panel being installed on the inner surface of a part of the inner face. An elimination system based on vibration of the ice formed is put in place on at least a part of the outer face and an ice formation prevention system using a hot fluid is put in place on at least a part of the inner face and either an ice elimination system or an ice formation prevention system using a hot fluid is installed on the inner face and on the outer face, a marking line marking the boundary between the two systems.

Abstract: An air intake structure for an aircraft nacelle is disclosed. The air intake structure delimits a channel and includes a lip having a U-shaped cross section oriented towards the rear, a first sound-absorbing panel fixed behind the lip and delimiting the channel, and a second sound-absorbing panel fixed behind the first sound-absorbing panel and delimiting the channel. Each sound-absorbing panel includes a cellular core which is fixed between an inner skin pierced with holes and oriented towards the channel, and an outer skin oriented in the opposite direction, where the inner skin of the first sound-absorbing panel has a thickness greater than the thickness of the inner skin of the second sound-absorbing panel, and where each of the inner skins includes a heat source which is embedded in the mass of the inner skin.

Abstract: A turbofan engine with a nacelle and a flow path, in which the nacelle comprises a movable cowl that makes it possible to define a window between the flow path and the outside, veils with a first edge fixed to the movable cowl and alternately assuming a folded position or a deployed position across the flow path, and a pneumatic system displacing a second edge of the veils from the folded position to the deployed position and vice versa. The pneumatic system comprises a rigid main roll, for each veil, at least one extendable secondary roll fixed to a second edge of the veil, and a pressurization and depressurization system which, alternately, generates a pressure or a depression in each secondary roll. Replacing the reverse doors and their driving mechanisms with flexible veils and a pneumatic system allows for a weight reduction.