Abstract: A de-icing element having a skin with a surface to be de-iced, at least one excitation actuator attached to the skin, the excitation actuator configured to excite the skin according to at least one predetermined vibration mode generating a deformation of the skin, the deformation of the skin comprising at least one antinode and one node. The skin having a characteristic thickness generally constant with, locally, at least one thickness variation that is localized according to the predetermined vibration mode or modes.

Abstract: A honeycomb structure having a core made up of a plurality of corrugated sheets which are superposed and adhesively bonded together is described. The corrugated sheets are made from a thermally insulating material. Bear filaments are made up of thermally conductive filaments. The honeycomb structure can be used when the ambient temperature exceeds, for example, 120° C.

Abstract: A forward secondary structure for a mounting pylon for a turbomachine, the forward secondary structure extending from upstream to downstream along a longitudinal axis and having a chassis clad with an aerodynamic fairing. The aerodynamic fairing includes two adjacent cowls each having an upstream portion, where each of the cowls extends lengthwise along the longitudinal direction and includes in its upstream portion a system for articulating the cowl to the chassis, by which system the cowl can pivot with respect to the chassis about an axis of rotation normal to the longitudinal axis, between a closed position in which all of an inner face of the cowl is pressed against the chassis and an open position in which the cowl frees up an opening in the forward secondary structure.

Abstract: An acoustic panel for an aircraft nacelle includes, from a central axis of the nacelle to the exterior thereof, a resistive skin perforated with sound-absorbing micro-perforations, a first attenuation stage, a septum perforated with holes, a second attenuation stage, and a back skin configured to provide the mechanical strength of the acoustic panel. The septum is a planar wall having a thickness greater than that of the resistive skin, preferably greater than 4 mm. Such a panel is configured to attenuate several frequency ranges one of which being a low-frequency range, while optimizing the weight, the cost and the air intake functions. The thickness of the septum, the dimensions of the holes in the septum, the OAR of the septum and the height of the second attenuation stage are adjusted to match the mean attenuated low frequency to the vibration frequency of the aircraft engine.

Abstract: An aircraft nacelle air intake includes sectors each having a lip forming portion, an outer panel forming portion and an inner panel forming portion. The outer panel forming portions and lip forming portions are formed by a continuous one-piece wall. At at least one junction between two adjacent sectors, an opening and a hatch are provided between the outer panel forming portions of the sectors. The inner panel forming portions and the lip forming portions of the sectors are edge to edge and fixed to each other by fixing devices accessible from the inside of the sectors and invisible from outside of the sectors. A maintenance method in which, when a zone of a sector is damaged, the sector concerned is removed as a whole and is replaced by a new of “recycled” sector is also described.

Abstract: An optimized protection against ice on the inner and outer faces of an aircraft engine nacelle air intake with the air intake including an outer face and an inner face meeting at a line at the longitudinally extreme, called extremum line, an acoustic panel being installed on the inner surface of a part of the inner face. An elimination system based on vibration of the ice formed is put in place on at least a part of the outer face and an ice formation prevention system using a hot fluid is put in place on at least a part of the inner face and either an ice elimination system or an ice formation prevention system using a hot fluid is installed on the inner face and on the outer face, a marking line marking the boundary between the two systems.

Abstract: A module ensuring an acoustic attenuation of a flow of a first fluid and a heat exchange between the first fluid and a second fluid. The module comprises a perforated first wall with a cutout, a second wall, a cellular structure extending from the second wall to the first wall, a recess provided in the cellular structure between a perforated bottom and a perforated top, and a heat exchanger which is fixed inside the recess between the bottom and the top and in which the second fluid circulates. Such a module ensures an attenuation of sound waves and a heat exchange without limiting the attenuation surface.

Abstract: A nacelle forward part of an aircraft propulsion assembly, includes an air inlet lip at the front end, an internal structure and an external panel extending the lip, and an annular stiffening frame formed around an axis of revolution and comprising an internal peripheral edge linked to the internal structure and an external peripheral edge linked to the external panel. The stiffening frame presents an inclination relative to the axis of revolution, its slope being oriented towards the front end of the nacelle forward part. The stiffening frame is configured to deviate, outside the nacelle of the propulsion assembly, an object striking the stiffening frame. The stiffening frame so configured is capable of withstanding the impacts of objects without breaking while enabling the object striking the stiffening frame to be deviated towards the exterior of the nacelle.

Abstract: An anti-icing protection system for an aircraft engine nacelle, the nacelle comprising an inner shroud provided with at least one acoustic panel, an air intake lip forming a leading edge of the nacelle, the protection system comprising a heat exchanger device including at least one heat pipe configured to transfer heat emitted by a heat source to the acoustic panel or panels.

Abstract: An optimized protection against ice on the inner and outer faces of an aircraft engine nacelle air intake with the air intake including an outer face and an inner face meeting at a line at the longitudinally extreme, called extremum line, an acoustic panel being installed on the inner surface of a part of the inner face. An elimination system based on vibration of the ice formed is put in place on at least a part of the outer face and an ice formation prevention system using a hot fluid is put in place on at least a part of the inner face and either an ice elimination system or an ice formation prevention system using a hot fluid is installed on the inner face and on the outer face, a marking line marking the boundary between the two systems.

Abstract: 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.

Abstract: A forward secondary structure for a mounting pylon for a turbomachine, the forward secondary structure extending from upstream to downstream along a longitudinal axis and having a chassis clad with an aerodynamic fairing. The aerodynamic fairing includes two adjacent cowls each having an upstream portion, where each of the cowls extends lengthwise along the longitudinal direction and includes in its upstream portion a system for articulating the cowl to the chassis, by which system the cowl can pivot with respect to the chassis about an axis of rotation normal to the longitudinal axis, between a closed position in which all of an inner face of the cowl is pressed against the chassis and an open position in which the cowl frees up an opening in the forward secondary structure.

Abstract: An air intake structure for a nacelle of an aircraft is disclosed having an air intake lip with a U-shaped section open towards the rear, an acoustic panel that extends the air intake lip towards the rear and on an inner side, an outer panel extending the air intake lip towards the rear and on an outer side, and a rear strengthening frame fixed between the outer panel and the acoustic panel, where the rear strengthening frame partly defines an inner volume that is immediately in front of the rear strengthening frame. The air intake structure comprises an impact absorber element positioned in the inner volume and the impact absorber element assumes the form of a structure that is deformable during an impact and that is at least partially filled with a fluid. The impact absorber element is a flexible shroud filled with a pressurized gas.

Abstract: An acoustic panel for an aircraft nacelle includes, from a central axis of the nacelle to the exterior thereof, a resistive skin perforated with sound-absorbing micro-perforations, a first attenuation stage, a septum perforated with holes, a second attenuation stage, and a back skin configured to provide the mechanical strength of the acoustic panel. The septum is a planar wall having a thickness greater than that of the resistive skin, preferably greater than 4 mm. Such a panel is configured to attenuate several frequency ranges one of which being a low-frequency range, while optimizing the weight, the cost and the air intake functions. The thickness of the septum, the dimensions of the holes in the septum, the OAR of the septum and the height of the second attenuation stage are adjusted to match the mean attenuated low frequency to the vibration frequency of the aircraft engine.

Abstract: 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.

Abstract: An anti-icing protection system for an aircraft engine nacelle, the nacelle comprising an inner shroud provided with at least one acoustic panel, an air intake lip forming a leading edge of the nacelle, the protection system comprising a heat exchanger device including at least one heat pipe configured to transfer heat emitted by a heat source to the acoustic panel or panels.

Abstract: An aircraft nacelle air intake includes sectors each having a lip forming portion, an outer panel forming portion and an inner panel forming portion. The outer panel forming portions and lip forming portions are formed by a continuous one-piece wall. At at least one junction between two adjacent sectors, an opening and a hatch are provided between the outer panel forming portions of the sectors. The inner panel forming portions and the lip forming portions of the sectors are edge to edge and fixed to each other by fixing devices accessible from the inside of the sectors and invisible from outside of the sectors. A maintenance method in which, when a zone of a sector is damaged, the sector concerned is removed as a whole and is replaced by a new of “recycled” sector is also described.

Abstract: An air intake structure for a nacelle of an aircraft is disclosed having an air intake lip with a U-shaped section open towards the rear, an acoustic panel that extends the air intake lip towards the rear and on an inner side, an outer panel extending the air intake lip towards the rear and on an outer side, and a rear strengthening frame fixed between the outer panel and the acoustic panel, where the rear strengthening frame partly defines an inner volume that is immediately in front of the rear strengthening frame. The air intake structure comprises an impact absorber element positioned in the inner volume and the impact absorber element assumes the form of a structure that is deformable during an impact and that is at least partially filled with a fluid. The impact absorber element is a flexible shroud filled with a pressurized gas.

Abstract: A nacelle forward part of an aircraft propulsion assembly, includes an air inlet lip at the front end, an internal structure and an external panel extending the lip, and an annular stiffening frame formed around an axis of revolution and comprising an internal peripheral edge linked to the internal structure and an external peripheral edge linked to the external panel. The stiffening frame presents an inclination relative to the axis of revolution, its slope being oriented towards the front end of the nacelle forward part. The stiffening frame is configured to deviate, outside the nacelle of the propulsion assembly, an object striking the stiffening frame. The stiffening frame so configured is capable of withstanding the impacts of objects without breaking while enabling the object striking the stiffening frame to be deviated towards the exterior of the nacelle.