Abstract: A method for manufacturing an acoustic element of a sound absorption structure including at least one cylindrical, conical or truncated conical chamber obtained from a flat preform shaped and then assembled in order to obtain the cylindrical, conical or truncated conical shape of the chamber. This manufacturing method makes it possible to obtain an acoustic element that has thin walls and is made from a material suited to its environment. An acoustic element obtained using the manufacturing method, a sound absorption structure comprising at least one such acoustic element and an aircraft powerplant comprising at least one such structure are also described.

Abstract: An acoustic absorption structure comprising a plurality of resonators. Each resonator comprises a first chamber which has a first mouthpiece delimited by an edge pressed against an inner surface of a porous zone of a skin so that the first chamber and the skin delimit a first cavity, a second chamber, in which is positioned the first chamber, which delimits, with the first chamber, a second cavity, at least one acoustic orifice passing through the first chamber, at least one drainage orifice passing through the first chamber and at least one drainage hole passing the second chamber, each drainage orifice and each drainage hole being configured to limit an accumulation of fluid in the resonator. Also, an aircraft propulsive assembly or an aircraft comprising the acoustic absorption structure are provided.

Abstract: An acoustic absorption structure includes: at least one acoustic element which has at least one cavity delimited by at least one enclosure comprising at least one first drainage orifice passing through the enclosure, and a rotational indexing system making it possible to position the acoustic element so that at least one first drainage orifice is positioned in proximity to or at a lowest point of the cavity. An aircraft propulsion assembly including such an acoustic absorption structure is also described.

Abstract: A double-enclosure acoustic element of small size, in particular for an aircraft acoustic panel. The acoustic element has a first enclosure with a mouth and a second enclosure with, at a front longitudinal end, a mouth and arranged inside the first enclosure, these first and second enclosures being joined together at the front. The acoustic element includes a slotting assembly system, the assembly system including at least one protruding element on the first edge of one of the first and second enclosures and at least one recess in the first edge of the other of the first and second enclosures, the protruding element and the recess having complementary shapes such that the protruding element can be slotted into the recess. Thus, the two enclosures can be assembled by quick and easy slotting.

Abstract: An acoustic absorption structure includes: at least one acoustic element which has at least one cavity delimited by at least one enclosure comprising at least one first drainage orifice passing through the enclosure, and a rotational indexing system making it possible to position the acoustic element so that at least one first drainage orifice is positioned in proximity to or at a lowest point of the cavity. An aircraft propulsion assembly including such an acoustic absorption structure is also described.

Abstract: A method for manufacturing an acoustic element of a sound absorption structure including at least one cylindrical, conical or truncated conical chamber obtained from a flat preform shaped and then assembled in order to obtain the cylindrical, conical or truncated conical shape of the chamber. This manufacturing method makes it possible to obtain an acoustic element that has thin walls and is made from a material suited to its environment. An acoustic element obtained using the manufacturing method, a sound absorption structure comprising at least one such acoustic element and an aircraft powerplant comprising at least one such structure are also described.

Abstract: An acoustic absorption structure comprising a plurality of resonators. Each resonator comprises a first chamber which has a first mouthpiece delimited by an edge pressed against an inner surface of a porous zone of a skin so that the first chamber and the skin delimit a first cavity, a second chamber, in which is positioned the first chamber, which delimits, with the first chamber, a second cavity, at least one acoustic orifice passing through the first chamber, at least one drainage orifice passing through the first chamber and at least one drainage hole passing the second chamber, each drainage orifice and each drainage hole being configured to limit an accumulation of fluid in the resonator. Also, an aircraft propulsive assembly or an aircraft comprising the acoustic absorption structure are provided.

Abstract: A structure which absorbs low-frequency sound comprising a perforated skin, a box having two lateral walls in the shape of a strip, that delimit between them an opening, and a bottom opposite the opening connecting the two lateral walls, the lateral walls becoming closer together with increasing distance from the opening to the bottom. The box is attached to the skin at the opening. Each lateral wall extends width-wise between the opening and the bottom. Each box has two tongues, each tongue being strip shaped, extending lengthwise over an entire box length, and width-wise between the opening and the bottom of the box. Each tongue has a first end attached along an edge of the opening and a second, free end which extends towards the bottom, becoming closer to the second end of the other tongue, where each tongue has an arcuate shape along its length.