An air inlet for an aircraft nacelle, including a lip and a front frame, which together form a duct with D-shaped section receiving hot air. The front frame is arranged in an advanced position inside the lip. The lip has de-icing grooves, which communicate with the duct and extend essentially downstream of the front frame. Downstream of the front frame, outside of the de-icing grooves, the lip has perforated zones provided with sound absorption holes. The air inlet includes a foil, which hermetically seals the de-icing grooves and is provided with sound absorption holes facing the perforated zones. The air inlet comprises acoustic panels inside the lip downstream of the front frame. The advanced position of the front frame, due to the de-icing grooves which ensure the de-icing of the lip downstream of the front frame, allows the acoustic treatment surface of the air inlet to be increased.

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.

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.

An acoustic damper has a sound pickup unit defining a plurality of pickup unit passageways. Hollow flexible tubes are connected to exit openings of the pickup unit passageways and extend outwardly therefrom. The hollow flexible tubes and pickup unit passageways define acoustic paths.

An acoustic barrier assembly includes a first wall that is gas impermeable. The acoustic barrier assembly further includes a second wall that is gas impermeable. The second wall is disposed opposite the first wall. The acoustic barrier assembly further includes a periphery wall coupling the first wall with the second wall in a manner that forms a pocket between the first wall and the second wall. The periphery wall is flexible, and the pocket is fluid-tight. The acoustic barrier assembly further includes a gas disposed in the pocket. The gas has a first molecular weight that is lower than a second molecular weight of air. The acoustic barrier assembly still further includes a biasing member that is disposed within the pocket. The biasing member is coupled with both the first wall and the second wall.

The present disclosure provides acoustic structures and related systems and methods which may be used to dampen or attenuate sound waves, including, for example, noise generated by or emanating from various aspects or components of turbomachines such as turbine engines. These acoustic structures include oblique polyhedral cellular structures, including converging polyhedral cells and diverging polyhedral cells, and related systems and methods of making and using such acoustic structures.

A method for providing a honeycomb core assembly that includes obtaining a honeycomb core having at least first and second cells that each define a cell interior having an open bottom and an open top, contacting the honeycomb core with a liquid foaming adhesive, contacting a hardening agent with the liquid foaming adhesive, and allowing the hardening agent and liquid foaming adhesive to react to harden and form a first barrier member that spans the cell interior of the first cell and a second barrier member that spans the cell interior of the second cell, thereby forming the honeycomb core assembly.

A structural panel includes a first skin, a second skin and a core. The core is connected to the first skin and the second skin. The core includes a corrugated sheet of wire mesh that includes a plurality of corrugations. Each of the corrugations extends vertically between and engages the first skin and the second skin.

An airflow profiled structure having a profiled leading edge. The profiled leading edge having, along a leading edge line, a serrated profile line with a succession of teeth and depressions. The airflow profiled structure also includes a porous acoustically absorbent region located towards the bottom of the depressions.

A sandwich acoustic liner assembly includes a honeycomb core and a thermoplastic fabric sheet positioned in overlying relationship and structurally bonded with the honeycomb core. Further included is a method for fabricating a sandwich acoustic liner assembly which includes the steps of positioning a thermoplastic fabric sheet in overlying relationship with a honeycomb core and bonding structurally the thermoplastic fabric sheet to the honeycomb core.