Abstract: An acoustic attenuation panel includes a cellular structure including a plurality of acoustic cells separated from one another by peripheral partitions, a perforated acoustic structure, the perforated acoustic structure and the cellular structure being formed in one piece in a first material, and a porous acoustic layer formed of a second material and fastened to a surface of the perforated acoustic structure by entangling the first material and the second material.

Abstract: A microfluidic system, including: a container, an ultrasound transmitter assembly, and a phononic crystal plate. The container is configured to accommodate a solution containing microparticles. The ultrasound transmitter assembly is configured to transmit ultrasonic waves to the phononic crystal plate, where the ultrasonic waves have a frequency which is the same as a resonance frequency of the phononic crystal plate. The phononic crystal plate is placed in the solution, and configured to generate a local acoustic field on a surface of the phononic crystal plate under excitation of the ultrasonic waves, and induce an acoustic microstreaming vortex to generate an acoustic streaming shear stress on the microparticles. The phononic crystal plate defines therein cavities, the respective cavities are arranged periodically in the phononic crystal plate, and all the respective cavities are filled with gas.

Abstract: A method for manufacturing a sound-absorbing panel with a sandwich structure for reducing noise impact of an aeronautic engine includes providing a first skin of a thermoplastic polymeric material, making a plurality of micro-holes through the first skin by mechanical punching of the first skin, securing the first skin to a central layer by arranging a structural adhesive layer between the first skin and the central layer and/or by a thermal weld between the first skin and the central layer, and securing the central layer to a second skin by arranging a structural adhesive layer between the central layer and the second skin and/or by a thermal weld between the central layer and the second skin.

Abstract: A method for manufacturing an acoustic absorption structure comprising a plurality of acoustic elements, each of which is positioned in one of the cells of a cellular panel. The method includes a step of manufacturing acoustic elements provided with at least two radial tongues, a step of manufacturing a cellular panel provided with slots configured to accommodate the radial tongues of each acoustic element, a step of force-fitting each acoustic element in one of the cells of the cellular panel until the radial tongues are accommodated in the slots. An acoustic absorption structure obtained using this method is provided.

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 treatment panel intended to be disposed on at least one wall of an aircraft propulsion unit in contact with a fluidic flow, the panel including a first, acoustically reflective skin, a second, acoustically porous skin intended to be in contact with the fluidic flow, and a honeycomb structure extending between the first skin and the second skin and having a plurality of cavities. The panel includes at least one acoustically transparent reinforcing wall passing through a plurality of cavities of the honeycomb structure and extending from the second skin to the first skin, forming a non-orthogonal angle with the first and second skins.

Abstract: A method for producing a nacelle inlet assembly includes forming a composite panel that has a carbon fiber reinforced polymer (CFRP) material. The composite panel is formed to have a curved contour that represents at least a portion of an annular barrel shape. The method includes applying a metallic coating to the composite panel to form a lipskin. The metallic coating is applied such that the metallic coating defines an exterior surface of the lipskin and the composite panel defines an interior surface of the lipskin. The method includes laser drilling a plurality of perforations through the lipskin. The laser drilling involves emitting a laser beam that impinges upon the interior surface of the lipskin and penetrates the CFRP material of the composite panel before penetrating the metallic coating and exiting the lipskin through the exterior surface.

Abstract: A method for forming a fiber-reinforced thermoplastic acoustic panel may comprise: stacking plies of thermoplastic composite sheets to a first thickness to form a top sheet; stacking plies of thermoplastic composite sheets to a second thickness to form a backskin; staking plies of thermoplastic composite sheets to a third thickness to form a stiffening member; forming the top sheet in a first contour; forming the backskin in a second contour, the second contour being different from the first contour; forming the stiffening member comprising a shape having a plurality of peaks and troughs; bonding the stiffening member to the top sheet and the backskin; and perforating the top sheet.

Abstract: A cellular sound insulation structure and associated aircraft, a cell of which is provided with a diaphragm which includes a membrane having at least one orifice passing through a thickness of the membrane, and at least one tube surmounting the orifice and extending from a face of the membrane into one compartment of the cell, the tube comprising a free end, forming an acoustic outlet, which is positioned at a distance (p) from the base cross section of the cell. Also, a method for manufacturing such a cellular sound insulation structure, as well as to a tool for inserting a diaphragm into a cell. Such a cellular structure makes it possible to treat a wider acoustic frequency spectrum, and its acoustic dimensioning as well as its manufacture are simplified.

Abstract: Sound absorbers using distributed absorption units each having an extended neck are provided. The absorption units can be, for example, Helmholtz resonators with extended neck (HRENs). The absorption units can be distributed in a lateral fashion, for example, in a checkerboard fashion with laterally, non-diagonally adjacent units having a different extended neck length and/or diameter. Each absorption unit can be, for example, a cylinder-structure core sandwiched between a back wall and a perforated plate.

Abstract: An acoustic core has a plurality of cell walls formed of an additive-manufacturing material and a resonant space defined by the plurality of cell walls. At least some of the resonant cells have sound-attenuating protuberances formed of an excess amount of the additive-manufacturing material having been intentionally introduced to the cell walls and protruding into the resonant space with a semi-random orientation and/or size.

Abstract: An acoustic attenuator comprises a first attenuation unit, a second attenuation unit, a welded section, and a communication part. A first acoustic damper is provided on an outer surface of a first acoustic liner, which faces toward a side opposite from an object, to form a first damper space that communicates with an internal space of the object. The second attenuation unit is attached to an outer surface of the object. The welded section is provided at least between the first acoustic damper and a second acoustic damper. The welded section secures the second attenuation unit to the first acoustic liner. The communication part is disposed in a position farther from an outer surface of the object than the welded section, allowing communication between the first damper space and a second damper space.

Abstract: A panel for attenuating noise is disclosed comprising a face skin having a first inner surface, a base skin having a second inner surface, a cellular core connected to and forming a plurality of cells between the face skin and the base skin, wherein the cellular core is defined by a cell structure having a plurality of cell walls extending between the face skin and the base skin defining each of the plurality of cells and a septum disposed within each of the plurality of cells, the septum defining an upper chamber proximate the face skin and a lower chamber proximate the base skin, wherein the face skin comprises a plurality of perforations fully through the face skin and in fluid communication with the upper chamber.

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: A system for mounting objects, such as acoustic panels to a surface is provided. The system includes a door in a façade panel for accessing a mounting structure adapted to receive a fastener that mounts the panel to the surface. The door can include a tab for identifying and opening the door. Methods for mounting objects with an access door and methods for manufacturing tiles are also provided.

Abstract: Systems for building modular quarter-wavelength resonators, and arrays of said resonators, include interlocking blocks having channels in them. Different block varieties can include those having straight channels and those having curved channels, to facilitate assembly of resonators of any desired configuration. Resonator length, and therefore resonance frequency, can be easily designed by adjusting the number of blocks used for a particular resonator.

Abstract: A thrust reverser door includes a backskin including an interior surface and an exterior loft surface. The thrust reverser door further includes a cover plate including a cover plate body having a first side and a second side opposite the first side. The thrust reverser door further includes a grid structure mounted to the second side of the cover plate body and the interior surface of the backskin.

Abstract: A soundproof fume discharge conduit adapted to be arranged between a ventilation system and an outlet chimney, the conduit defining a fume path therein, wherein at least one side surface of the conduit is provided with at least two protrusions, each protrusion internally defining a respective step-shaped recess, whereby the path is provided with at least two step-shaped recesses adapted to reflect sound waves propagating along the path, and wherein the step shape of each recess is defined by two first walls, which are incident at a first end thereof, and at least one wall of the two first walls is coated with a first sound absorbing material.

Abstract: A system for dampening noise generated by a gas turbine engine is disclosed. In various embodiments, the system includes a fan exit guide vane having a leading edge, a trailing edge and a pocket that extends in a chordwise direction between the leading edge and the trailing edge; and an acoustic panel configured to be received within the pocket, the acoustic panel including a back sheet, a face sheet and a core disposed between the back sheet and the face sheet, the core having a first cavity extending between a first wall and a second wall and a second cavity disposed within the first cavity.

Abstract: A Helmholtz resonator having a plurality of resonator chamber modules formed into an array. The array is configured to dampen sound. A module of the plurality of resonator chamber modules includes a first chamber and a second chamber. The first and second chambers have different lengths and are tuned to dampen different frequencies of sound.

Abstract: The object of the invention can be a method of manufacturing a product in the form of a sandwich comprising a core and outer layers. The outer layers may be composed of composite material comprising a fiber-reinforced polymeric matrix. The method uses an insert of heat-resistant material, for example silicone. The object of this invention can be to provide a method of manufacturing a sandwich that dissociates the choice of material of the core of the sandwich from the choice of the material of the outer layers.

Abstract: An alternating clockwise and counterclockwise helicoid cell structure for use in acoustic panels. The cell structure geometry may be easily replicated and tiled using additive manufacturing. The cell structure has at least an outer cavity and an inner cavity. The cavities are coaxial, share the same height, same entrance side, and same cell structure floor. The inner cavity includes a number of equal-volume inner chambers rotated uniformly in a first direction around the shared central axis; and the outer cavity includes a second number of equal-volume outer chambers rotated uniformly in an opposite direction to the first direction around the shared central axis. In various embodiments, one or more perforated baffles may extend, internally, across a chamber, perpendicular to direction of sound waves at the location of the perforated baffle. In various embodiments, one or more port openings from the outer cavity to the inner cavity may be present.

Abstract: A turbine engine has: a compressor; a combustor; a turbine, a gas flowpath passing consecutively through the compressor, combustor, and turbine; and inlet member along the gas flowpath upstream of the compressor. The inlet member includes the unitarily-formed single piece combination of: a three dimensional (3D) lattice portion; and a nose cap body surrounding the lattice portion.

Abstract: A method for producing an acoustically resistive structure includes the steps of creating, consolidating and cutting a first layer of reinforcing fibres embedded in a first thermoplastic resin having a first melting point so as to obtain an interlayer, a step of laying a second layer of reinforcing fibres against a first face of the interlayer, a second consolidation step of consolidating the second layer of reinforcing fibres embedded in a second thermoplastic resin having a second consolidation temperature lower than the first melting point of the first resin so as to obtain a non-perforated external layer bound to the interlayer, a step of perforating the external layer and a step of laying an internal layer on a second face of the interlayer. An acoustically resistive structure obtained from the method as well as a sound-absorption panel including such an acoustically resistive structure are also described.

Abstract: A structured panel is provided that includes a first skin with a plurality of perforations, a second skin and a core. The core forms a plurality of cavities vertically between the first skin and the second skin. Each of the cavities is respectively fluidly coupled with one or more of the perforations. The cavities include a first cavity. An element of the core is configured with a multi-layered structure. The multi-layered structure includes a first layer and a second layer attached to the first layer. The first layer is configured with a first rib projecting into the first cavity.

Abstract: An acoustic unit includes an acoustically septumized cell, and a vapor chamber attached across the cell. The vapor chamber is configured to employ vapor-liquid phase changing to help move heat past the cell.

Abstract: An acoustic liner and a method of attenuating noise are provided. The acoustic liner includes a face sheet, a back sheet spaced from the face sheet, and a core layer extending between the face sheet and the back sheet. The core layer includes a plurality of resonant cells, each resonant cell including at least one cell wall coupled to the back sheet along a cell wall base edge. The at least one cell wall extends from the back sheet at an angle toward the face sheet. The at least one cell wall further coupled to the face sheet along a cell wall top edge. The resonant cell is formed in a predetermined shape and contains a volume in a space defined by the at least one cell wall, the back sheet, and the face sheet. The cell wall base edge length is greater than the cell wall top edge length.

Abstract: An engine nacelle for a turbofan engine, having a nacelle wall and an engine inlet, wherein the nacelle wall has a stationary downstream section and an upstream section that is displaceable in the axial direction, and the displaceable upstream section is displaceable between a first upstream position and a second downstream position. A ring-shaped seal is provided, formed between the stationary section and the displaceable section of the nacelle wall, wherein, in the first position of the displaceable section, the engine nacelle forms a ring-shaped additional flow channel that extends from the outer side of the nacelle wall to the engine inlet and via which ambient air can flow into the engine inlet, and the ring-shaped additional flow channel is closed in the second position of the displaceable section, wherein the stationary section, the ring-shaped seal and the displaceable section adjoin each other.

Abstract: An acoustic panel for attenuating sound and a method of making the acoustic panel. A septum structure is created comprising a layer of chopped fibers between layers of uncured epoxy. The structure is forced onto the open ends of the cells so that the edges of the cell walls cut the structure into pieces, with each piece having the same cross-sectional size and shape as one of the cells, and the pieces are pushed further into the cells to a specific position. The epoxy layers are cured, and holes are created in the cured epoxy layers to expose the chopped fibers and create septum layers within the cells. The chopped fibers may be sufficiently long and/or strong to provide structural support across each cell but sufficiently short and/or weak to be cut by the edge of the cell wall, and may melt at a higher temperature than the epoxy cures.

Abstract: A sound-damping panel. The sound-damping panel includes a first face sheet. The sound-damping panel also includes a core connected to the first face sheet. The core has a honeycomb structure. Walls of the honeycomb structure are embedded with a viscoelastic material configured to dampen sound in a pre-selected frequency range. The sound-damping panel also includes a second face sheet connected to the core, the second face sheet opposite the first face sheet relative to the core.

Abstract: An acoustic panel for a turbomachine, in particular for an aircraft, includes two skins that are substantially parallel and between which extend cavities forming Helmholtz resonators, one of the skins being perforated by orifices opening into the cavities and forming necks of the Helmholtz resonators, vibrating masses being provided in at least some of the cavities and connected to cavity walls by an elastic junction housed in the cavity.

Abstract: A Laminar Inducing Apparatus (LIA) inducing laminar airflow to a turbine engine or a propulsion fan. The LIA produces turbulent-free airflow with a light aerospace structure that can replace single purpose structure in the wing or empennage. Laminar airflow to the propulsion fan or the turbine engine is ensured in a greater number of flight conditions and angles of attack. Active control of flight can be enhanced by the manipulating the turbulent boundary surface as a flight control surface. LIA simply reduces the risk of FOD or bird strike damage. In addition to the engineered, laminar benefits, LIA provides greater safety from ground ingested FOD and more silent vertical take-off and landing. In summary, LIA ensures laminar airflow and acoustic attenuation to a propulsion fan or a turbine engine for a greater number of flight conditions, angles of attack, and from ground ingested FOD during vertical takeoff and landing.

Abstract: A soundproof structure has at least one soundproof cell including a frame having a hole portion and a film fixed to the frame so as to cover the hole portion. The soundproof cell is disposed in an opening member having an opening in a state in which a film surface of the film is inclined with respect to an opening cross section of the opening member and a region serving as a ventilation hole, through which gas passes, is provided in the opening member.

Abstract: An acoustic liner for a turbine engine, the acoustic liner includes a support layer that includes a set of partitioned cavities with open faces, a facing sheet operably coupled to the support layer such that the facing sheet overlies and closes the open faces, a set of perforations located in the facing sheet and in fluid communication with a corresponding one of the cavities to form a set of acoustic resonators, and at least a subset of the perforations have an axially-oriented, relative to the axial flow path, inlet.

Abstract: An exemplary geared turbomachine assembly includes an acoustic treatment that is in an unducted area of a geared turbomachine.

Abstract: Acoustic core segments include splicing resonant cells that resemble a first segment of a whole resonant cell configured to overlap and align with counterpart splicing resonant cells of another acoustic core segment so as to define a splice joint. The splicing resonant cells include one or more fastening elements configured to couple with corresponding counterpart splicing resonant cells thereby together defining coupled resonant cells. Acoustic liners have an acoustic core assembly that includes a first acoustic core segment mechanically joined with a second acoustic core segment by a combination of splicing resonant cells of the first acoustic core segment overlapping and aligning with splicing resonant cells of the second acoustic core segment so as to define a splice joint, and a plurality of fastening elements coupling splicing resonant cells of the first acoustic core segment with splicing resonant cells of the second acoustic core segment.

Abstract: A liner assembly includes a core and a septum coupled to the core. The liner assembly also includes a facesheet coupled to the septum. The facesheet includes a plurality of slots defined therethrough. Each slot of the plurality of slots is substantially continuous over a selected portion of a surface and perpendicular to or parallel to a centerline of the liner assembly.

Abstract: An underlayment system is provided that includes a plurality of protrusions that extend from a common base member. The protrusions and base member can include an opening therethrough that allows for subsequent layers of material, such as adhesive, to interact and bond to each other. The protrusions are arranged in such a way to contain a wire, string, or heating element, within a receiving area. The arrangement of the protrusions allow for routing of the wire, string, or heating element in a variety of angles, bends, and other routing layouts.

Abstract: An acoustic attenuation device includes resonator panels stacked in a thickness direction of the device. Each resonator panel is tuned to a different frequency range and includes a plurality of openings through which excited air resonates. The resonator panels are placed adjacent to other resonator panels such that all openings are accessible to the environment.

Abstract: Two or more soundproof cells arranged in a two-dimensional manner are provided. At least one of the soundproof cells is a first soundproof cell configured to include a first frame having a first through-hole. At least one of the other soundproof cells is a second soundproof cell including a second frame having a second through-hole and a film fixed to the second frame. A first shielding peak frequency, which is determined by the first through-hole of the first soundproof cell and at which a transmission loss is maximized, is present on a lower frequency side than a first natural vibration frequency of the film of the second soundproof cell, and sound in a predetermined frequency band centered on the first shielding peak frequency is selectively insulated.

Abstract: An air vent is mounted in a vehicle window frame. The air vent includes a one-piece body having an interior face and an exterior face. A passive ventilation feature includes an air pathway that extends between a first opening in the interior face to a second opening in the exterior face. A forced air ventilation feature is carried by the body. The forced air ventilation feature includes a ventilation fan, an exhaust outlet and a closure for the exhaust outlet that is displaceable between open and closed positions.

Abstract: The invention disclosed herein is an automotive acoustic panel including a porous sound-absorption material made from a polymer and an expanded perlite. One or more silane compounds may be coupled or coated onto the expanded perlite while a coupling agent and a chemical foaming agent may additionally be added to the automotive acoustic panel.

Abstract: A laser cuts overlapping ribbons of acoustic material into acoustic devices. An automatically controlled manipulator includes an end effector having groups of placement tools for simultaneously placing multiple acoustic devices in a cellular core. The placement tools include mandrels provided with vacuum pickups for picking up and holding the acoustic devices during transport to the core. A vision system aligns the placement tools with the cells of the core. The end effector includes a thermal radiation device for bonding the acoustic devices to the core.

Abstract: A plate assembly for a motor vehicle may include a first plate, a second arranged substantially parallel to the first plate, the second plate defining a plurality of perforations, and a mesh core including a plurality of wire bundles, the core arranged between the plates, wherein the mesh core is rigidly joined to an inner surface of each plate via the perforations.

Abstract: Methods and apparatus for debris separation generally comprise a vacuum hose attachment comprising a collar and an attachment body. The attachment body further comprises an external face, external face openings, nubs, valley, an internal baffle, and internal baffle openings. In some embodiments, the external face openings are arranged in a lattice pattern and separated by nubs in a first direction and valleys in a second direction. In some embodiments, the attachment body may further comprise handgrips. The present invention also includes a method for separating debris via a vacuum hose attachment.

Abstract: A structure ensuring acoustic attenuation of a flow of a first fluid and heat exchange between a first fluid and a second fluid. The structure includes a first wall which is perforated, a second wall, and a plurality of intermediate walls extending between the first wall and the second wall. For each intermediate wall, there is a pipe intended to receive the second fluid and inscribed within the intermediate wall. Such a structure makes it possible to optimally integrate the acoustic wave attenuation function and the heat exchange function.

Abstract: A panel for lining a gas turbine engine fan casing includes a honeycomb core sandwiched between a backing skin and an outer skin. The backing skin is attached to an inner surface of the casing such that the outer skin forms a radially inward facing surface of a fan duct of the engine. The panel is joined along its sides to similar neighbouring panels such that, in use, the joined panels form a row of panels along the inner surface of the casing. The outer skin or the backing skin includes two face sheets bonded on top of each other, which are arranged such that their edges along each panel side that joins to a neighbouring panel are staggered in the direction of the row. The interfaces between the abutting face sheet edges are therefore correspondingly staggered in the direction of the row.

Abstract: There is provided a soundproof structure that can selectively block sound having a specific frequency emitted from equipment, automobiles, and general households and can change the cutoff frequency of the sound in accordance with a change in the frequency of sound to be blocked. The above problem is solved by providing a laminated film, in which two or more films each including one or more holes drilled therein are laminated, and two rigid frames, which fix the laminated film so as to be interposed from both sides of the laminated film, and making at least parts of the one or more holes in the respective films of the laminated film overlap each other.

Abstract: A gas turbine engine may include at least one of a fan inlet case and a bypass duct case. Additionally, the gas turbine engine may include a variable volume acoustic damper coupled to the at least one of the fan inlet case and the bypass duct case, wherein the variable volume acoustic damper is configured to damp acoustic energy. The variable volume acoustic damper may include a case and a diaphragm movably coupled within the case. An acoustic volume may be defined by a position of the diaphragm relative to the case and the acoustic volume may correspond to and may be configured to damp acoustic energy of a gas turbine engine.

Abstract: A panel (10) for sound suppression consists of a multiplicity of rigid elements (12) that extend parallel to each other, with gaps between adjacent rigid elements. Within each gap a vortex chamber (15) is defined to attenuate acoustic waves. The elements (12) may have curved edge portions (14), the edge portions (14) of adjacent elements (12) overlapping to define the vortex chamber (15), and also defining a first channel (16a) and a second channel (16b) communicating with the vortex chamber (15) at its periphery and aligned with a tangential component, such that if a fluid were to flow in through either channel (16a or 16b) the fluid would enter the vortex chamber (15) with a rotational sense relative to the vortex chamber (15), the rotational sense being the same for both the channels (16a, 16b). Such a sound-attenuating panel may for example be used as part of a wall of a loudspeaker housing (50).