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 anterior part of a nacelle of an aircraft propulsion assembly, which comprises an air intake lip, an outer panel extending an outer part of the air intake lip, an inner structure extending an inner part of the air intake lip, a front frame connecting the outer wall to the air intake lip or to the inner structure. The outer panel and the outer part of the air intake lip together form an outer wall of the anterior part. The front frame and the outer wall are connected to one another by assembly means located inside the anterior part. The anterior part constituted in this manner ensures laminar flow of the air on an outer surface of the anterior part and reduces drag. A nacelle of a propulsion unit, comprising an anterior part of this kind is also provided.

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: An acoustic treatment panel in which each cell includes a plurality of conduits which extend from the porous acoustically resistive structure to the reflective layer of the acoustic treatment panel, each conduit including at least one opening set away from the porous acoustically resistive structure and configured to cause the inside and the outside of the conduit to communicate.

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 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: An assembly including two juxtaposed acoustic panels. Resistive faces of the acoustic panels are in the continuation of one another. A first resistive face extends as far as the first end wall of a first panel. The first end wall is in contact with a second end wall of a second panel in the region of the first resistive face and of the second resistive face. A connecting piece is interposed between the first end wall and the second end wall over a part of the length thereof so that the connecting piece does not extend as far as the first and second resistive faces. That makes it possible to form an acoustic cladding that is continuous, exhibiting no non-acoustic zone or reduced-acoustic zone at the junction between the acoustic panels of which it is formed. A nacelle of an aircraft propulsion unit is one application.

Abstract: A method for manufacturing deicing acoustic skin for an aircraft acoustic panel, using a fiber spacing device. The manufacturing method includes at least one step for manufacturing a layer assembly having a deicing layer supplied with electrically conductive fibers embedded in a resin and two insulating layers arranged on either side of the deicing layer, and a baking step. The method provides for fitting, during baking, a spacing device on the layer assembly, the spacing device having pins passing through said layer assembly, perforations being produced at the locations of the pins after the withdrawal of the spacing device, the fitting of the spacing device making it possible to produce perforations with desired sizes and shapes, in a simple and effective manner, and with a reduced manufacturing duration.

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 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 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 production method for an acoustic panel comprising a step of producing a composite structure, a step of providing inserts, wherein each insert comprises a nozzle formed as a hollow cylinder with a through-bore and a cap comprising a base formed as a cylinder and a cover formed as a cone, and wherein the base is accommodated in the bore, a step of positioning the inserts in the composite structure by penetration of the cover into the composite structure so that the bore opens at one side and the other of the composite structure, a step of polymerizing during which the composite structure with the inserts is polymerized, a step of removing the caps, a first step of fixing a honeycomb structure to the polymerized composite structure, and a second step of fixing a rear skin to the honeycomb structure.

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: The invention relates to a wall made from a composite material comprising at least two layers of fibers (18, 18?) embedded in a resin matrix, a crack being able to spread in said wall in a direction of propagation, characterized in that it comprises at least one longilineal metal reinforcement (20), oriented in a direction secant to the direction of propagation, inserted between two layers of fibers (18, 18?) of the wall.

Abstract: An acoustic treatment panel in which each cell includes a plurality of conduits which extend from the porous acoustically resistive structure to the reflective layer of the acoustic treatment panel, each conduit including at least one opening set away from the porous acoustically resistive structure and configured to cause the inside and the outside of the conduit to communicate.

Abstract: An acoustic treatment panel including a porous acoustically resistive structure which includes at least one external layer which is in contact with the external environment and which has through holes, internal strips including several openings which communicate with the inside of the cells of the panel and connecting canals, interposed between the external layer and the internal strips, which ensure that the floor-section openings communicate with at least one through hole of the external layer.

Abstract: An air intake structure for an aircraft nacelle including an air intake lip with a U-shaped cross section which is open towards the rear, with a rear end, an acoustic panel including an inner wall, wherein the air intake lip has at a rear end a contact surface oriented towards the inside of the air intake lip, in that the contact surface takes the shape of a bevel which points towards the rear and against which the inner wall is placed, in that at the point of the bevel, the inner wall runs on from the air intake lip and in that level with the contact surface, the air intake lip is fixed to the inner wall by first fasteners. The bevelled shape restricts the possibility of dust and water being halted in their progress and blocking up the air intake structure as a result.

Abstract: An aircraft nacelle includes a first subassembly consisting of a pipe (112) channeling an airflow in the direction of an engine having a covering or panel (118) for acoustic treatment, including, from the inside to the outside, a reflecting layer (120), at least one cellular structure (122), and at least one acoustically resistive structure (124) forming the aerodynamic surface of the pipe (112), as well as a second subassembly consisting of a lip (116) and a front frame (126), characterized in that it includes at least one connection element (134) which is separate from the two subassemblies and connected to a portion of the pipe (112) and to a portion of the lip forming an extension of the portion of the pipe at different points so as to be capable of enabling a relative movement between the two subassemblies.

Abstract: An aircraft nacelle includes a lip whose surface contacts with the aerodynamic streams extends inside the nacelle by an inside wall that delimits a layer that empties at a power plant and outside of the nacelle by an outside wall, a first front frame connects the inside and outside walls, delimiting an annular pipe with the lip, and a rear frame connects the inside and outside walls at a junction zone between the inside pipe and power plant pipe, for a given cross-section of the nacelle along a plane that contains the longitudinal axis of the nacelle, a point A at the intersection between the rear frame and the inside wall, and a point B at the intersection between the rear frame and the outside wall, with B being offset toward the rear of the nacelle relative to A over more than 50% of the rear frame's periphery.

Abstract: An aircraft nacelle including a pipe (32), a peripheral wall (34), a lip (36), and a front frame (38) connecting the peripheral wall (34) and the pipe (32) and forming with the lip (36) a space (50) in which the hot air that is provided for frost treatment can circulate, with the pipe (32) including a coating (44) for the composite material acoustic treatment, is characterized in that the nacelle includes at least one element (52) made of a heat-conducting material inserted between the lip (36) and the pipe (32) ensuring the continuity of the aerodynamic surfaces of the lip (36) and the pipe (32) and the propagation of heat from the space (50) toward the rear of the nacelle, whereby the at least one element (52) includes a coating (54) for acoustic treatment that is made of a heat-resistant material.