Abstract: A multilayer acoustic treatment panel including a first cellular-structure core sandwiched between a perforated skin and an intermediate skin; and a second cellular-structure core sandwiched between the intermediate skin and a continuous skin. The perforated skin includes at least one pair of high-porosity zones presenting a perforation ratio greater than a perforation ratio of a remainder of the perforated skin and including an inlet zone and an outlet zone longitudinally spaced apart from each other, the high-porosity zones of a given pair communicating through the first cellular-structure core and the intermediate skin with the two ends of a soundwave flow channel arranged in the second cellular-structure core.

Abstract: An aircraft pylon for mounting a dual-flow or triple-flow jet engine, the pylon including an upper surface for connection to the aircraft, two side flanks, and a flange on the lower portion of the pylon. The pylon further includes at least one portion that extends downstream from the cold flow nozzle of the jet engine and lies in the cold flow and, on the portion thereof extending into the cold flow beyond the nozzle, at least one opening, positioned on one of the flanks of the pylon, by which an air stream is injected into or drawn from the gas flow that flows along the flanks of the pylon.

Abstract: The invention provides a device for acoustical treatment of the noise emitted by a bypass turbojet comprising a primary cowl having in an outer surface an inner annular acoustic treatment panel and a secondary cowl including in an inner surface an outer annular acoustic treatment panel arranged facing the inner panel. The inner and outer panels include respective central panel portions facing each other and extending axially over a common predetermined length, the length of the central panel portions lying in the range one-fifth to four-fifths of the total length of the panels, and the ratio between the acoustic resistances of the central panel portions being not less than 2.

Abstract: A multilayer acoustic treatment panel including a first cellular-structure core sandwiched between a perforated skin and an intermediate skin; and a second cellular-structure core sandwiched between the intermediate skin and a continuous skin. The perforated skin includes at least one pair of high-porosity zones presenting a perforation ratio greater than a perforation ratio of a remainder of the perforated skin and including an inlet zone and an outlet zone longitudinally spaced apart from each other, the high-porosity zones of a given pair communicating through the first cellular-structure core and the intermediate skin with the two ends of a soundwave flow channel arranged in the second cellular-structure core.

Abstract: An aircraft pylon for mounting a dual-flow or triple-flow jet engine, the pylon including an upper surface for connection to the aircraft, two side flanks, and a flange on the lower portion of the pylon. The pylon further includes at least one portion that extends downstream from the cold flow nozzle of the jet engine and lies in the cold flow and, on the portion thereof extending into the cold flow beyond the nozzle, at least one opening, positioned on one of the flanks of the pylon, by which an air stream is injected into or drawn from the gas flow that flows along the flanks of the pylon.

Abstract: The invention provides a device for acoustical treatment of the noise emitted by a bypass turbojet comprising a primary cowl having in an outer surface an inner annular acoustic treatment panel and a secondary cowl including in an inner surface an outer annular acoustic treatment panel arranged facing the inner panel. The inner and outer panels include respective central panel portions facing each other and extending axially over a common predetermined length, the length of the central panel portions lying in the range one-fifth to four-fifths of the total length of the panels, and the ratio between the acoustic resistances of the central panel portions being not less than 2.

Abstract: The present invention relates to a structural or non-structural turbojet engine fan casing connecting arm that also acts as a flow straightener downstream of the fan rotor. Its distinctive feature is that it is constructed to form an acoustic attenuator. In particular, it comprises a closed cavity and perforations on one of the faces so as to form a Helmholtz resonator. The arm forms part of the intermediate casing.

Abstract: The present invention relates to a structural or non-structural turbojet engine fan casing connecting arm (8B) that also acts as a flow straightener downstream of the fan rotor (3). Its distinctive feature is that it is constructed in such a way as to form an acoustic attenuator. In particular, it comprises a closed cavity and perforations (83) on one of the faces (8B in, 8Bex) so as to form a Helmholtz resonator. The arm forms part of the intermediate casing (8).

Abstract: A cowl for a turbomachine nozzle, the cowl having a plurality of repeated patterns disposed circumferentially at a trailing edge, each pattern being asymmetrical about a midplane of the pattern containing a longitudinal axis of the cowl, and each pattern having a first portion inclined radially towards the inside of the cowl and a second portion inclined radially towards the outside of the cowl.

Abstract: A soundproofing panel comprises a honeycomb core sandwiched between a solid skin and a porous skin, the cells of the honeycomb being divided in the direction of its thickness into at least two resonant cavities by a least one partition which is traversed by passages interlinking the cavities. The partitions are formed by a plurality of hollow microbeads having porous walls, the microbeads being bonded to one another and to the walls of the honeycomb at their points of contact. Such a soundproofing panel combines high performance in terms of linearity as a function of the level of sound excitation, attenuation band, bulk and mechanical strength.