An acoustic panel for a turbomachine, in particular for an aircraft, includes two skins that are substantially parallel and between which extend cavities forming Helmholtz resonators, one of the skins being perforated by orifices opening into the cavities and forming necks of the Helmholtz resonators, vibrating masses being provided in at least some of the cavities and connected to cavity walls by an elastic junction housed in the cavity.

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.

A face skin for an acoustic panel may comprise a sheet defining a first surface and a second surface. A plurality of slots may be formed through the face skin using abrasive blasting. Each slot of the plurality of slots may comprise a first semi-circular wall and a second semi-circular wall opposite the first semi-circular wall.

A panel includes a corrugated base with base corrugations configured from first base segments and second base segments. A first of the base corrugations includes a first of the first base segments and a first of the second base segments that is non-parallel to the first of the first base segments. The first of the base corrugations forms a first channel that extends laterally between and longitudinally along the first of the first base segments and the first of the second base segments. A corrugated stringer includes a plurality of stringer corrugations arranged longitudinally along and within the first channel. The stringer corrugations are configured from first stringer segments and second stringer segments. A first of the stringer corrugations includes a first of the first stringer segments and a first of the second stringer segments that is non-parallel to the first of the first stringer segments.

The nacelle can have an inlet fluidly connecting a main gas path of a gas turbine engine core, the inlet having an inlet edge connecting an external skin to an internal duct wall, and a step formed in a surface of at least one of the skin and the duct wall, the step delimiting a first portion of the surface from a second portion of the surface, the second portion of the surface being recessed relative to the first portion of the surface, the second portion of the surface extending away from both the step and the inlet edge, whereas the first portion of the surface extends between the inlet edge and the step.

The nacelle can have an inlet portion having a duct wall and an outer skin, the duct wall being annular around an axis and having a surface forming a radially-outer delimitation to a gas path upstream of a fan area, the duct wall extending from a rounded inlet edge of the nacelle to the fan area, a cavity located inside the inlet portion, a compressed air inlet leading into the cavity, and an outlet fluidly connecting the cavity to the gas path, the outlet having a plurality of apertures disposed circumferentially around the duct wall, the apertures sloping circumferentially.

A nacelle for a turbomachine is provided and includes an inner wall that is annular about a longitudinal axis of the nacelle, the annular inner wall being designed to surround part of the turbomachine. The nacelle further includes an annular outer wall surrounding the annular inner wall. The annular outer wall includes a first acoustically porous part, and the annular inner wall including a second acoustically porous part. The first and second porous parts are arranged facing one another so as to allow soundwaves, emitted by the turbomachine housed in the nacelle, to pass through the annular inner wall and then the annular outer wall so as to escape from the nacelle.

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.

The invention regards an acoustic liner which comprises: a facing sheet that comprises holes, the facing sheet having a porosity and a facing sheet thickness, a backing sheet, and a plurality of cells arranged between the facing sheet and the backing sheet, the cells having a cell depth and each cell defining a cavity. A plurality of internal necks are provided that extend from the inner side of the facing sheet towards the backing sheet, each internal neck being located around a hole of the facing sheet, thereby extending the longitudinal length of the hole. The invention further regards a gas turbine engine with such acoustic liner.

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.