Abstract: An acoustic absorber cell (1) for mounting on a turbojet wall in contact with a fluid flow, the cell (1) having a resonant cavity (2) presenting a wall (30) having at least one orifice (4) associated with a neck (5) having a tube (51) extending inside the resonant cavity (2) and projecting from the wall (30). The neck (5) also having a tubular ring (52) coaxial with the tube (51) and movable relative to the tube (51), and the cell (1) includes electromagnetic actuator (6) for moving the ring (52) along the tube (51), and controller (7) for controlling the electromagnetic actuator (6) and configured to control movement of the ring (52) along the tube (51) as a function of the operating speed of the turbojet between at least first and second positions defining respective first and second resonant frequencies of the resonant cavity (2).

Abstract: A ring of vanes for an aircraft turbine engine, the ring presenting an axial direction and a radial direction and including a first annular sheath presenting an inside surface and a second annular sheath presenting an inside surface facing the first inside surface of the first annular sheath, the first and second sheaths being coaxial and defining between them a flow passage for a gas stream. The ring further includes both partially annular acoustic treatment panels including resonant cavities and also vanes extending in the radial direction between the first and second sheaths. Each vane includes a radial airfoil with at least two attachment tabs at each radial end of the airfoil fastened to the first or second sheath, and the inside surface of at least one of the first and second annular sheaths and the corresponding attachment tabs are covered by acoustic treatment panels arranged between the airfoils.

Abstract: An acoustic treatment panel including a cellular structure core sandwiched between a solid skin and a perforated skin, and a plurality of domes made of porous fabric and extending from at least one of the skins into the insides of the cells of the cellular structure towards the other skin so as to define at least two resonant cavities inside each cell of the cellular structure.

Abstract: A supply duct of a compressor of a turbine engine, formed from internal and external walls of revolution around an axis and opposite one another to define a circulation stream of a fluid, is provided. The stream allows the fluid to be routed from the inlet of the duct to the inlet of the compressor. The radius of the external wall at the inlet of the duct is greater than the radius of the duct at the inlet of the compressor. The duct includes a portion for which the radius of the external wall along the portion is less than the radius of the external wall at the inlet of the compressor, and the radius of the internal wall along the portion of the duct is less than the radius of the internal wall at the inlet of the compressor.

Abstract: An acoustic absorber cell (1) for mounting on a turbojet wall in contact with a fluid flow, the cell (1) comprising a resonant cavity (2) presenting a wall (30) having at least one orifice (4) associated with a neck (5) comprising a tube (51) extending inside the resonant cavity (2) and projecting from said wall (30). The neck (5) also comprises a tubular ring (52) coaxial with the tube (51) and movable relative to said tube (51), and the cell (1) includes translation means (6) for moving the ring (52) along the tube (51), and control means (7) for controlling the translation means (6) and configured to control movement of the ring (52) along the tube (51) as a function of the operating speed of the turbojet between at least first and second positions defining respective first and second resonant frequencies of the resonant cavity (2).

Abstract: An acoustic panel intended to be fixed internally to a fan casing of a turbojet engine, including an exterior face and an interior face which are curved about an axis, and two axially opposed transverse faces, the exterior curved face having at least one first recess on the side of a first transverse face and at least one second recess on the side of the opposite transverse face, said recesses each an attachment, in which said recesses do not open onto the interior curved face of the panel. Also covered are the turbojet engine including these panels and the method of mounting them.

Abstract: A heat exchange and noise reduction panel the panel for an aircraft comprising: an external surface intended to be swept by an airflow and from which fins extend along a first and a second main predetermined direction; cavities forming Helmholtz resonators, linked to the first ends of channels for the passage of air, the second ends of which communicate with said airflow, such that said channels form necks, referred to as Helmholtz resonators, extending substantially along the first direction; and at least one oil flow chamber extending between said external surface and said at least one cavity, and intended to discharge the thermal energy carried by the oil, characterized in that wherein said channels are formed, at least in part, inside said fins.

Abstract: An aircraft having a wing and an aeroengine having a longitudinal main axis M and including a ducted nacelle with at least one fan, the wing including an acoustic treatment surface on a bottom portion of its outer shell on either side of the main longitudinal axis M and over a width L perpendicular to the longitudinal axis M that is not greater than three times the diameter D of the fan, the acoustic treatment surface comprising a layer of porous material for attenuating acoustic waves coming from the fan.

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 acoustic panel intended to be fixed internally to a fan casing of a turbojet engine, including an exterior face and an interior face which are curved about an axis, and two axially opposed transverse faces, the exterior curved face having at least one first recess on the side of a first transverse face and at least one second recess on the side of the opposite transverse face, said recesses each an attachment, in which said recesses do not open onto the interior curved face of the panel. Also covered are the turbojet engine including these panels and the method of mounting them.

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 one-piece soundproofing panel which is attached within an circumferential air blower casing of a turbomachine, with an axis, in which circulates an airflow from upstream to downstream, is disclosed. The panel includes a circumferential rigid seat with a longitudinal cylindrical part, arranged to axially extend with respect to the axis A of the turbomachine, having an outside surface, intended to come to extend facing with an internal surface of the air blower casing, and an internal surface to which is applied a soundproofing coating; and an annular fastening flange, formed at the upstream end of the longitudinal cylindrical part, radially outwardly extending, the fastening flange being arranged to cooperate with a fastening flange of the air blower casing.

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: One-piece soundproofing panel intended to be attached within an circumferential air blower casing of a turbomachine, comprising an axis, in which circulates an airflow from upstream to downstream, the panel including a circumferential rigid seat comprising a longitudinal cylindrical part, arranged to axially extend with respect to the axis A of the turbomachine, comprising an outside surface, intended to come to extend facing with an internal surface of the air blower casing, and an internal surface to which is applied a soundproofing coating and an annular fastening flange, formed at the upstream end of the longitudinal cylindrical part, radially outwardly extending, the fastening flange being arranged to cooperate with a fastening flange of the air blower casing.

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.