Abstract: The present disclosure concerns a method for manufacturing a composite panel including a cellular central core interposed between two skins. The manufacturing method includes the steps of manufacture of an element with a cellular structure comprising a cellular core structure interposed between two layers of structural plies intended to form the skins, positioning of the element with a cellular structure within a mold, formation of drains on either side of the cellular core structure, infusion of the element with a cellular structure so as to impregnate it with a resin, carrying out a draining of the resin through the drains in the element with a cellular structure during the infusion step, the drains having a geometry configured to provide draining, and polymerization of the impregnated element with a cellular structure to form the composite panel.

Abstract: The present disclosure concerns an acoustic attenuation panel for an aircraft turbojet engine nacelle and a method for manufacturing this panel. The acoustic attenuation panel includes an alveolar central core interposed between an acoustic front skin comprising perforations and a rear skin, the acoustic attenuation panel including a front structure and a rear structure. The front structure includes the acoustic front skin and a first network of alveolar walls, the rear structure including the rear skin and a second network of alveolar walls, the first and second networks of alveolar walls being complementary so as to form, in an assembled position, the alveolar central core, the front structure and the rear structure being positioned opposite to each other and so that the network of alveolar walls of a structure is spaced from the skin of the other structure facing it by a clearance d.

Abstract: 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.

Abstract: 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.

Abstract: The present disclosure concerns a method for manufacturing a composite panel including a cellular central core interposed between two skins. The manufacturing method includes the steps of manufacture of an element with a cellular structure comprising a cellular core structure interposed between two layers of structural plies intended to form the skins, positioning of the element with a cellular structure within a mold, formation of drains on either side of the cellular core structure, infusion of the element with a cellular structure so as to impregnate it with a resin, carrying out a draining of the resin through the drains in the element with a cellular structure during the infusion step, the drains having a geometry configured to provide draining, and polymerization of the impregnated element with a cellular structure to form the composite panel.

Abstract: The present disclosure concerns an acoustic attenuation panel for an aircraft turbojet engine nacelle and a method for manufacturing this panel. The acoustic attenuation panel includes an alveolar central core interposed between an acoustic front skin comprising perforations and a rear skin, the acoustic attenuation panel including a front structure and a rear structure. The front structure includes the acoustic front skin and a first network of alveolar walls, the rear structure including the rear skin and a second network of alveolar walls, the first and second networks of alveolar walls being complementary so as to form, in an assembled position, the alveolar central core, the front structure and the rear structure being positioned opposite to each other and so that the network of alveolar walls of a structure is spaced from the skin of the other structure facing it by a clearance d.