Abstract: An air intake structure for a turbojet engine nacelle includes an inner panel to be attached to a fan casing, and an external panel capable of a translational movement in a longitudinal direction of the nacelle. The external panel incorporates a portion of an air inlet lip able to provide a junction between the inner panel and the external panel, and each of the air inlet lip portion and the inner panel is equipped, at least in the region of a joining end, with an acoustic attenuation structure. In particular, at least one of the joining ends is equipped with a radial buffer able to come into contact with a corresponding joining flange exhibited by the other joining end when the external panel is in a closed position.

Abstract: A composite acoustic liner has a septumized cellular core. Septa are installed in the core as the individual core cells are being formed. Individual tools are used to both form the cells of the core and index the septa within the cells. The septa and the cellular core are cocured.

Abstract: An example acoustic treatment for a geared turbomachine establishes a portion of the core cowl aft the fan cowl.

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

Abstract: An apparatus for mitigating noise in a printer can include a plate having a plurality of holes distributed across the plate and extending through the plate. A portion of the plurality of holes can be dimensioned and configured to absorb acoustic noise across a given frequency band and another portion of the plurality of holes can be dimensioned and configured to absorb acoustic noise across another frequency band in a media path of a printer. The apparatus further can include an acoustic baffling material to cover the plate and that can be configured to dampen the acoustic noise across the given frequency band and the other frequency band.

Abstract: A ceiling system comprises a pair of spaced overhead longitudinal grid support members and a light-weight ceiling panel suspended therefrom. The panel may be an acoustical honeycomb panel in one embodiment. Localized elongated reinforced areas or sections are formed on the top facing which support a plurality of hangers mounted on each section. The reinforced sections coincide in arrangement with the layout of the support members and structurally strengthen the top facing in select areas. In one embodiment, each reinforced section may comprise a stiffening spline attached to the top facing. The ceiling panel is hung from the grid support members via the hangers and reinforced sections. Fasteners may be used to attach the hangers to the reinforced sections which resist pullout when the panel is hung. In certain embodiments, the reinforced sections extend longitudinally through a central portion of the panel to prevent sagging between the panel sides.

Abstract: Aspects of the disclosure are directed to a structure comprising: a plurality of cells, a first non-permeable insert in a first cell of the plurality of cells, the first insert configured to constrict, by at least a first threshold amount, a flow of fluid in the first cell such that: acoustic power over a frequency range is attenuated by the structure by at least a second threshold amount, and a resonant frequency associated with the structure is shifted by at least a third threshold amount.

Abstract: Acoustical materials of the type provided in panel form for purposes of controlling or adjusting the acoustics of an interior space, such as an auditorium or concert hall, conference room, etc., and commonly referred to as architectural acoustical panels or ceiling panels. A panel comprises multiple layers, such as a surface layer which faces the room or sound source, which in turn comprises wood veneer laminated to a supporting layer and defines a plurality of microperforations extending entirely through, the surface layer. An acoustical absorbing layer may be a wood wool material or, most preferably, high-density fiberglass having a particular orientation, along with a combination of a support material or ribbing, which may define a plurality of cells in which the fiberglass lies. A back support layer may be perforated or solid.

Abstract: A stepped acoustic structure having multiple degrees of acoustic freedom for reducing noise generated from a source. Acoustic septum caps are anchored at the same depth within the cells of the stepped acoustic structure. The multiple degrees of acoustic freedom that is usually provided by locating the septum portions of the septum caps at different depths within the cells is obtained by placing steps within the cells which reduce the cross-sectional area of the cell. Depth control portions are optionally included in the septum caps so that the septum portions of different septum caps are located at different depths within the stepped acoustic structure. Various combinations of steps and depth control portions are used to provide an acoustic structure having multiple degrees of acoustic freedom even though the acoustic septum caps are anchored at the same depth within the structure.

Abstract: A trim panel for the interior of an aircraft, the panel having a multilayer structure and including an outer layer made of material impervious to air, and which is positioned in use facing the fuselage of the aircraft; an inner layer made of trim material, and which in use defines the interior; a structural layer interposed between the inner and outer layer; and acoustic energy dissipating material, also interposed between the inner and outer layer; the inner layer being made of porous material allowing airflow towards the acoustic energy dissipating material.

Abstract: A sandwich panel including a core having a first major side and an opposed second major side, the core defining cavities, a first liner sheet connected to the first major side, the first liner sheet defining apertures, wherein each aperture provides fluid communication with an associated cavity, and a bulk absorber material and/or a thermal conductor material received in at least a portion of the cavities.

Abstract: A fiber preform for a turbine ring sector obtained by three-dimensional weaving and including a base-forming first portion, two tab-forming L-shaped portions each presenting two branches, two ends of the first portion being extended by respective ones of the first branches, and a second portion connecting together the two tabs, first and second strips woven together forming the first branches, a first fraction of the thicknesses of the second branches, and the first portion, there being a non-linked zone between them that is situated in the first branches and in the first portion, and a third woven strip forming the second portion and a second fraction of the thickness of the second branches of each of the tabs.

Abstract: An acoustic damping article includes a substrate, wherein the substrate has a surface area S. The acoustic composition further includes a polymer resin. The polymer resin coats partially the surface area with a set of areas. The ratio of the coated areas over the surface area S is less than 1 and the polymer resin coverage is not greater than about 500 g/m2. Embodiments of the present disclosure include an acoustic damping article including a release liner; and an acoustic damping composition disposed on the release liner. The acoustic damping composition partially coats the release liner, and the acoustic damping composition has a Patterned Interlayer Stiffness of at least about 1 GN/m3.

Abstract: An apparatus for mitigating noise in a printer can include a plate having a plurality of holes distributed across the plate and extending through the plate, the holes being dimensioned and configured to mitigate acoustic noise in a printer. A mesh material can cover the plurality of holes, wherein the mesh material can increase air flow resistance through the holes and thereby facilitate removal of acoustic noise from a media path in the printer.

Abstract: A nacelle inlet for an aircraft engine of a type having an engine fan case with a forward flange includes an acoustic inner barrel having a forward edge and an aft edge, an outer shell having a nose lip portion with a trailing inner edge, and an outer barrel portion having an aft portion. The nacelle inlet also includes an aft attachment flange configured to attach the inlet to the forward flange of the engine fan case, and an aft bulkhead having an aft end and connecting the outer barrel portion of the outer shell to the aft attachment flange. The forward edge of the acoustic inner barrel is connected to the trailing inner edge of the nose lip portion, and the aft portion of the inner barrel is attached to the aft attachment flange.

Abstract: A method and apparatus comprising a composite panel and a number of structures to reduce noise radiation from the composite panel. The composite panel has a first face sheet, a second face sheet, and a core located between the first face sheet and the second face sheet. The number of structures is associated with the first face sheet. The number of structures has a mass with a configuration to reduce a speed of waves propagating in the composite panel such that noise radiating from the composite panel is reduced.

Abstract: An aircraft engine assembly comprising a nacelle configured to surround the aircraft engine having an inlet open to ambient air and an annular acoustic panel provided within the nacelle. Sound emitted from the aircraft engine is attenuated by the annular acoustic panel. The annular acoustic panel comprises an open framework, made from a first material, forming a plurality of cells.

Abstract: Described herein are microperforated polymeric films comprising: opposed first and second surfaces separated by a first certain distance (40a); and a plurality of channels perpendicular to the first and second surfaces, wherein a first opening (20a-c) of a channel intersects the first surface and a second opening (22a-c) of the channel intersects the second surface; wherein the diameter of the first opening is larger than the diameter of the second opening and the second openings on the second surface are spaced apart by a second certain distance (50a); wherein the ratio of the first certain distance to the second certain distance is at least 0.25; and further wherein the second surface has an open area of at least 10%. Also described are methods of making and using such microperforated polymeric films.

Abstract: A system and method for the acoustic analysis of a body, in particular a fuselage structure of an aircraft, is provided including: inputting data for geometry, material, boundary conditions and acoustic parameters of the body, generating a body idealized in terms of its structural mechanics, and a cavity simulating the interior of the body, on the basis of the data inputted as a numerical body model, inputting the geometry of the body with a pattern of nodes and the generation of finite elements, stimulating an acoustic loading case by subjecting the body model to at least one sound pressure wave at a defined frequency, analyzing the effect of the sound pressure wave on the body model, and outputting a sound reduction index (R) for the body with reference to that frequency.

Abstract: Fan flutter attenuators are optimized so that they occupy the minimum area of the intake duct, and so can be accommodated more easily, without significantly compromising the area available for liners targeting community noise. In such circumstances resonators for flutter frequencies are typically associated with existing acoustic liner and take the form of chambers incorporating labyrinthine cores for absorption of acoustic frequency waves or utilize Helmholtz chambers with appropriate volumes and inlet pipe aperture configurations for tuning to desired flutter frequencies to be attenuated.

Abstract: Composite structures for space vehicles and other aerospace vehicles are disclosed herein. In one embodiment of the disclosure, a space vehicle pressure vessel includes composite panels or sidewalls with septumized core. In another embodiment, a splice joint for joining septumized composite panels in space vehicle structures is disclosed herein.

Abstract: A multi-sectional acoustic septum that includes sections which have different acoustic resistance properties. The multi-sectional acoustic septums extend vertically with the acoustic cell and are capable of increasing the effective acoustical length of the acoustic cell. The multiple acoustic properties provided by the multiple acoustic sections also make it possible to target specific frequency ranges within the overall frequency range of the acoustic cell.

Abstract: A door structure is provided having two outer dampening layers, each outer dampening layer having a base surface and a damping surface, and an inner compartmentalized layer adjacent to the damping surfaces of the two outer dampening layers, the inner compartmentalized layer includes at least two compartments, wherein the damping surfaces of the two outer dampening layers are substantially unconstrained relative to the inner compartmentalized layer such that the damping surfaces are deformable.

Abstract: A self-supporting acoustic insulation panel (1) comprising a visible wall (3) that is not self-supporting and an invisible wall (2) that is not self-supporting facing a source (50) of soundwaves. A porous core (20) is arranged between the visible wall (3) and the invisible wall (2), a plurality of link elements (5) each extending from the invisible wall (2) towards the visible wall (3), each link element (5) passing through an orifice (21) in said core (20) and being connected to the visible wall (3) and to the invisible wall (2), each link element (5) separating the visible wall (3) from the invisible wall (2) and mechanically linking the visible wall (3) with the invisible wall (2) while acoustically decoupling the visible wall (3) from the invisible wall (2).

Abstract: Embodiments of thermal-acoustic sections for an aircraft for reducing noise along an acoustic path produced from an acoustic source are provided herein. The thermal-acoustic section comprises a first porous layer having a first characteristic acoustic impedance. A second porous layer is disposed adjacent to the first porous layer and has a second characteristic acoustic impedance that is greater than the first characteristic acoustic impedance. The thermal-acoustic section is configured to be positioned along the acoustic path such that at least a portion of the noise from the acoustic source is directed through the first porous layer to the second porous layer to promote absorption of the noise.

Abstract: An acoustic structure for a gas turbine engine comprising an noise reduction layer and a fire protector layer connected to the noise reduction layer. The noise reduction includes a perforated inner wall adapted to be in contact with a first fluidic environment, and an noise reduction adjacent to the inner wall. The fire protector layer includes a non-perforated outer wall adapted to be in contact with a second fluidic environment having potentially a fire, a fire protector adjacent to the outer wall, and a pressure resisting wall disposed between the fire protector and the noise reduction. The second fluidic environment is under a pressure lower than a pressure of the first fluidic environment.

Abstract: A honeycomb structure dial includes cells in which septums are located to provide acoustic dampening. The cells are formed by at least our walls wherein at least two of the walls are substantially parallel to each other. The septums include warp fibers and weft fibers that are substantially perpendicular to each other. The septums are oriented in the honeycomb cells such that the weft fibers and/or warp fibers are substantially perpendicular to the parallel walls.

Abstract: An acoustic panel device includes a panel member and a mount. The panel member includes a porous material. The mount is arranged to captively support the panel member. The mount can be a frame that surrounds the panel member. The frame can define a channel, and a portion of the panel member is disposed in the channel.

Abstract: The bandwidth or acoustical range of an acoustic structure is increased by locating a sound wave guide within the acoustic cell. The wave guide divides the cell into two acoustical chambers. The two chambers provide an effective increase in resonator length of the cell.

Abstract: An element (26) for sound absorption is intended for being mounted on components of aircrafts, such as engine nacelles. The element includes a face-sheet (28), which is, at least in a region thereof, acoustically permeable, a substantially sound-reflective back-sheet (30) and a honeycomb layer (32), “sandwiched” between the face-sheet (28) and the back-sheet (30) and defining a mesh structure which has hollow cells (34, 34?) laterally neighboring one another. The cells (34, 34?) are adapted to make the sound waves that enter through the face-sheet (28) and are reflected by the back-sheet (30) resonate inside their side walls. The element (26) has a passage (36) that connects together a group of the cells (34, 34?), thereby causing the cells to acoustically cooperate with one another.

Abstract: Honeycomb cores for use in aerospace applications include two honeycomb core sections operably joined at a splice joint, the splice joint defined by a foam adhesive that is sandwiched between a sheet of film adhesive. Methods of assembling honeycomb cores also are disclosed herein.

Abstract: A noise control flooring system includes a resilient layer of extruded polymer monofilaments and a porous separation layer overlying at least a portion of the resilient layer. The porous separation layer carries a floating solid substrate layer thereupon and enhances the speed of drying of the floating solid substrate layer.

Abstract: A method for repairing a sound attenuation panel is disclosed. The panel includes a structuring skin in metal material, a resistive layer in metal material and a honeycomb structure as acoustic absorption material directly added onto the structuring skin and resistive layer. The method includes a step in which one reinforcing pin is inserted into the thickness of the attenuation panel and a step in which the reinforcing pin is secured by welding in a controlled atmosphere to the structuring skin and resistive layer respectively.

Abstract: Apparatus and methods for attenuating noise, vibration, and/or acoustic energy in a turbomachine. The apparatus includes a first base plate having first base plate perforations defined therethrough. The apparatus also includes first and second spacers each extending from the first base plate, being spaced apart from each other, and defining a first channel therebetween. The apparatus further includes a first insert disposed in the first channel and having insert perforations defined therethrough, the first base plate, the first and second spacers, and the first insert at least partially defining a first acoustic chamber therebetween, wherein the base plate perforations and the insert perforations are in communication with the first acoustic chamber.

Abstract: A multi-sectional acoustic septum that includes sections which have different acoustic resistance properties. The multi-sectional acoustic septums extend vertically with the acoustic cell and are capable of increasing the effective acoustical length of the acoustic cell. The multiple acoustic properties provided by the multiple acoustic sections also make it possible to target specific frequency ranges within the overall frequency range of the acoustic cell.

Abstract: The bandwidth or acoustical range of an acoustic structure is increased by locating a sound wave guide within the acoustic cell. The wave guide divides the cell into two acoustical chambers. The two chambers provide an effective increase in resonator length of the cell.

Abstract: The invention pertains to a composite panel with a first cover layer, a second cover layer and a first core layer that is arranged between the first cover layer and the second cover layer and features a plurality of cells that are separated from one another by walls at least in certain areas, wherein the first cover layer features a draining layer. The inventive composite panel may be distinguished from a composite panel according to the state of the art in that a second core layer with a plurality of cells that are separated from one another by walls at least in certain areas is arranged between the first cover layer and the first core layer.

Abstract: The invention relates to a broadband sound absorber (1) which comprises a sound-absorbing filler material between two microperforated film webs (2) which are contiguous on their edges, said filler material optionally containing heavy fillers. The broadband sound absorber (1) achieves excellent acoustic insulation and has microperforations (4) all over or only in sections, said filler material optionally containing heavy fillers (mass density) and one or both microperforated film webs (2) having the same thickness across their surface or thickened portions (3, 5) of the same or a different material in some sections.

Abstract: A sound-insulating curtain includes a sound-absorbing core formed by laminating porous sheets and films, is covered by covers, and sewn in an integrated manner. Even after being integrally laminated, adjacently laminated layers are not excessively restrained in places other than sewn areas, and therefore displacement and deformation between layers caused by sound pressure can be tolerated. Sound absorption effects are appropriately produced by each layer, which tolerates such displacement and deformation, while reliably maintaining integrity during handling. Thus, the entire curtain maintains the ability to absorb sounds, efficiently attenuates noise that attempts to pass through the curtain, and suppresses the transmission of noise, thereby enabling noise to be reliably prevented from passing through the curtain.

Abstract: An acoustic panel includes a first cellular layer with cells having a first axis, a second cellular layer with cells having a second axis, and a perforated septum layer separating the first layer and the second layer. The cells of both layers have an end distal to the septum layer and an end which meets the septum layer, and the maximum diameter of the cells of the first layer is less than the maximum diameter of the cells of the second layer.

Abstract: A method for producing a double-layer or triple-layer sound-absorbing panel (10) is specified, said panel consisting of a support panel (20) and at least one cover panel or coating (30, 35) of the support panel (20), the cover panel or coating (30, 35) being fixedly connected to the support panel (20). In this case, an open-pore (121) support panel is provided as the support panel (20) and the sound-absorbing panel (10) is arranged on each side (12, 13) provided with a cover panel or coating (30, 35) with a device opposing said side emitting a laser beam, the upper face (12) of said panel (10) being subjected to the laser beam, which is designed to burn away material from the cover panel or coating (30, 35) facing said laser beam over the depth in the direction of the laser beam in a plurality of holes (31).

Abstract: A nacelle assembly according to an exemplary aspect of the present disclosure includes, among other things, a core nacelle defined at least partially about a core engine, a fan nacelle mounted at least partially around the core nacelle to define a fan bypass flow path, and a variable area fan nozzle in communication with the fan bypass flow path. The variable area fan nozzle has a first fan nacelle section and a second fan nacelle section downstream of the first fan nacelle section. The first fan nacelle section and the second fan nacelle section are axially movable relative to one another to define an auxiliary port to vary a fan nozzle exit area and adjust fan bypass airflow. The auxiliary port is defined between the first fan nacelle section and the second fan nacelle section. The first fan nacelle section comprises a first acoustic system which provides an acoustic impedance configured to attenuate a noise characterized by a leading edge of the second fan nacelle section.

Abstract: Honeycomb cores for use in aerospace applications include two honeycomb core sections operably joined at a splice joint, the splice joint defined by a foam adhesive that is sandwiched between a sheet of film adhesive. Methods of assembling honeycomb cores also are disclosed herein.

Abstract: The present invention relates to panels that can be used to cover interior surfaces in buildings, for instance in auditoriums, open-plan offices etc., where the panels can be used in buildings with thermally activated building systems (TABS) in which balancing of acoustics and thermal comfort is a well-recognized challenge. According to a first embodiment of the invention there is provided a panel comprising one or more sound-absorbing elements (3) and sub-regions (7, 8, 9) that connect the front (11) of the panel with the rear (12) of the panel, and in which sub-regions (7, 8, 9) sound-absorbing elements (3) are not present, whereby said sub-regions (7, 8, 9) ensure thermal transmission through the panel.

Abstract: Honeycomb sections are bonded together with seams made up of an adhesive that is carried by a linked-segment seam support. The seams are particularly useful for splicing together curved honeycomb sections that contain acoustic septum. The curved acoustic honeycomb sections are spliced or seamed together to form engine nacelles and other acoustic damping structures.

Abstract: A cellular material barrier system for reducing sound transmission. The cellular material system includes a planar cellular metamaterial arrangement which includes at least one unit cell, the unit cell includes a sound normalizing arrangement, and a planar metamaterial arrangement coupled to the sound normalizing arrangement on a first side, the planar metamaterial arrangement includes a plate, and a frame affixed to the plate, the sound normalizing arrangement configured to normalize incident sound received at non-normal angle to thereby convey sound at normal angles to the planar metamaterial arrangement, the unit cell further comprising a back layer that is coupled to the sound normalizing arrangement on a second side, opposite the first side, the back layer is made from a porous material, including at least one of a fibrous layer, polymeric foams, ceramic foams, and metallic foams.

Abstract: Sound absorbency is imparted on a panel, which has increased strength and rigidity, by laminating a foam resin that is not originally permeable and does not absorb sound, and surface sheets that are not originally permeable and do not absorb sound. A sound absorption panel 1, obtained by laminating a foam resin 20 comprising closed cells and aluminum alloy sheets 10 (metal sheets), has a plurality of holes 30 formed therein, which penetrate the foam resin 20 and the aluminum alloy sheets 10 in the thickness direction. The holes 30 are formed by forcing a needle 40 (hole-forming means) through the foam resin 20 and the aluminum alloy sheets 10.

Abstract: An inlet for an aircraft engine nacelle having an acoustic barrel panel, a septum buried or sandwiched within the acoustic barrel panel, and a perforated face sheet. The inlet may be located forward of an engine and/or an engine fan housed within the aircraft engine nacelle. Both the septum and the perforated face sheet may have perforations or holes therein of varying sizes and varying distances apart from each other. The smaller the area of the perforations or holes and the further apart they are from each other, the higher the impedance of a given area of the septum or the perforated face sheet. The impedance of the septum and/or the perforated face sheet may progressively increase in a direction away from the engine fan.

Abstract: The bandwidth or acoustical range of a nacelle or other type of acoustic structure is increased by acoustically coupling honeycomb cells together to form pairs of acoustic cells that have an effective acoustic or resonator length that is up to twice that of either acoustic cell taken alone.

Abstract: The present invention relates to a method for manufacturing a body provided with a honeycomb structure, which body is designed preferably axis-symmetrical, with sheet-metal parts being provided with a wave-like structuring by means of a forming process and formed to ring elements, with the sheet-metal parts being shaped and designed in a substantially identical way as regards their structuring, with adjacent sheet-metal parts being arranged offset to one another and then joined together to form the honeycomb structure.