Abstract: An acoustic treatment panel including acoustic absorption cells each comprising a bottom wall, a porous inlet wall, an enclosure extending in an axial direction between the bottom wall and the inlet wall, and a first acoustic horn extending inside the enclosure between a first opening and a second opening that is smaller than said first opening, the first opening facing said inlet wall. Each cell comprises a second horn extending inside the enclosure in the first axial direction between a first opening of the second horn and a second opening of the second horn that is smaller than said first opening.

Abstract: 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.

Abstract: An acoustic panel for an aircraft propulsion unit, comprises a core and an entry layer in contact with the core, the entry layer comprising lower elements and upper elements, each comprising an inner face, an outer face and at least one through-hole, the inner faces of the lower elements and upper elements being in contact with each other and forming a channel defining a baffle and opening into a cell of the core.

Abstract: An acoustic absorption cell including a bottom wall extending in a plane orthogonal to an axial direction, an enclosure including a first axial end secured to the bottom wall, and an acoustic horn extending inside the enclosure between a first opening of the horn and a second opening of the horn smaller than the first opening, the horn being secured to a second axial end of the enclosure opposite the first axial end, and the first and second openings of the horn each extending in a plane orthogonal to the axial direction. The horn includes at least one retaining arm protruding from the horn inside the enclosure and fixed to the bottom wall or to the enclosure.

Abstract: An acoustic treatment panel intended to be disposed on at least one wall of a turbojet in contact with a fluid flow, the panel comprising a first sheet, a second sheet parallel to the first sheet and having a first face intended to be in contact with a fluid flow and a second face facing the first sheet, and acoustic treatment cells extending between the first and second sheets and each including an enclosure and a cavity delimited by the enclosure. The enclosure of each cell comprises two openings facing one another, at least one of the openings being coincident with an opening of the enclosure of an adjacent cell.

Abstract: An acoustic absorption cell including a bottom wall extending in a plane orthogonal to an axial direction, an enclosure including a first axial end secured to the bottom wall, and an acoustic horn extending inside the enclosure between a first opening of the horn and a second opening of the horn smaller than the first opening, the horn being secured to a second axial end of the enclosure opposite the first axial end, and the first and second openings of the horn each extending in a plane orthogonal to the axial direction. The horn includes at least one retaining arm protruding from the horn inside the enclosure and fixed to the bottom wall or to the enclosure.

Abstract: An acoustic treatment panel intended to be disposed on at least one wall of a turbojet engine in contact with a fluid flow, the panel including a first acoustically reflective plate, a second plate and a plurality of cavities mounted between the first plate and the second plate and including a plurality of cells. The second plate is a one-piece plate through which a plurality of channels pass, each opening out on the one hand onto a first orifice formed on a first face of the second plate and on the other hand onto a second orifice formed on a second face of the second plate, the length of each channel extending between its first orifice and its second orifice being greater than the thickness of the second plate.

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, wherein said channels are formed, at least in part, inside said fins.

Abstract: An acoustic treatment panel intended to be disposed on at least one wall of a turbojet engine in contact with a fluid flow, the panel including a first acoustically reflective plate, a second plate and a plurality of cavities mounted between the first plate and the second plate and including a plurality of cells. The second plate is a one-piece plate through which a plurality of channels pass, each opening out on the one hand onto a first orifice formed on a first face of the second plate and on the other hand onto a second orifice formed on a second face of the second plate, the length of each channel extending between its first orifice and its second orifice being greater than the thickness of the second plate.

Abstract: 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.

Abstract: An acoustic panel for an aircraft propulsion unit, comprises a core and an entry layer in contact with the core, the entry layer comprising lower elements and upper elements, each comprising an inner face, an outer face and at least one through-hole, the inner faces of the lower elements and upper elements being in contact with each other and forming a channel defining a baffle and opening into a cell of the core.

Abstract: A turbomachine vane includes an electroacoustic source including two membranes fixed on a support arranged such that the membranes and the support delimit a first cavity. The membranes are arranged on two opposite sides of the first cavity between the two aerodynamic surfaces of the vane. A first of the aerodynamic surfaces includes a first region arranged facing a first of the membranes for the passage of acoustic waves. The membranes and membrane vibration device are configured such that the membranes vibrate in phase opposition and along a same emission direction by applying forces to the support such that the resultant force is approximately zero. The mechanical energy lost in the form of vane deformations due to membrane vibrations can thus be minimized.

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: The invention relates to an aircraft turbofan type engine (1) comprising an air intake duct (2) having an inner face provided with an acoustic attenuation shroud (11) located upstream from a fan (3) of this engine (1). This acoustic attenuation shroud (11) comprises a regular alternation of first portions and second portions with different first and second thicknesses along the radial direction, the number of alternations being greater than twice the number of passing azimuth acoustic vibration modes occurring in the engine (1) without the acoustic attenuation shroud (11) operating under conditions corresponding to a landing phase and a take-off phase.

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: 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 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: 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: 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.