Abstract: Aspects of the invention are directed to an acoustic resonator with improved impingement cooling effectiveness. The resonator includes a plate with an inside face and an outside face. A plurality of passages extend through the plate. The resonator includes a side wall that extends from and about the plate. A plurality of cooling tubes are attached to the resonator plate such that an inner passage of each cooling tube is in fluid communication with a respective passage in the resonator plate. The resonator can be secured to a surface of a turbine engine combustor component to define a closed cavity. The ends of the cooling tubes are spaced from the surface. Thus, a coolant can enter the passages in the plate and can be directed to the surface so as to impingement cool the surface. The cooling tubes can minimize coolant loss by dispersion in the cavity.

Abstract: The insert for an engine exhaust system has at least one conical section of flexible mesh of metallic or other high temperature resistant fiber. Each section includes a rigid anchor or attachment ring having an outer diameter closely conforming to the inner diameter of the exhaust pipe, with the anchor ring being welded to the mesh material or the mesh being crimped between two concentric rings. A smaller diameter support ring may be provided at the opposite end of the conical mesh, with the support ring braced by a series of radial arms. A coil spring may be placed within the mesh for additional support, and/or the outer surface of the mesh may be wrapped with a glass fiber batt for additional sound control if desired. The device may serve to reduce the sound output of the exhaust system, and/or may serve as a spark arrestor as well.

Abstract: Repairs and overhaul procedures are scheduled and implemented with a surprisingly low frequency. Repair and overhaul procedures are implemented wherein conventional noise suppression exhaust sound attenuation systems receive structural and functional enhancements for promoting longevity of efficient system operations. Degradation deficiencies of conventional configurations of sound attenuation systems for exhaust augmenters and deflector panels are avoided or prevented so that insulation re-packing rates may be minimized. Apparatus and associated methodology establish and implement maintenance protocols for installing specially-designed kits in existing sound attenuation systems.

Abstract: The noise reducing equipment of the present invention is used in combination with a vertically oriented sound barrier wall to reduce the level of noise from a source of sound such as traffic generated on one side of the sound barrier wall and comprises an assembly composed of a predetermined number of interconnected resonant chambers mounted in tandem to said sound barrier wall in a relationship such that the assembly extends from said sound barrier wall on the side thereof opposite the source of sound with the resonant chamber closest to the sound barrier wall having a volumetric area larger than the volumetric area possessed by each of the other resonant chambers and an additional sound barrier section extending from the most distant resonant chamber relative to the location of the sound barrier wall. In addition, at least one external surface of the assembly should be coated with a photo-catalyst comprising titanium dioxide.

Abstract: Methods and apparatus are provided for an exhaust duct having an externally replaceable acoustic liner. The exhaust duct includes a forward section that is configured to be axially coupled with a bulkhead collar on the aircraft, a body section that is coupled to the forward section and a stinger cap that includes the replaceable acoustic liner. The replaceable acoustic liner is configured to be slideably received by the body section.

Abstract: A cooled acoustic liner useful in a fluid handling duct includes a resonator chamber 52 with a neck 56, a face sheet 86, and a coolant plenum 80 residing between the face sheet and the chamber. Coolant bypasses the resonator chamber, rather than flowing through it, resulting in better acoustic admittance than in liners in which coolant flows through the resonator chamber and neck. In one embodiment, the liner also includes a graze shield 88. Openings 40, 38 penetrate both the face sheet and the shield to establish a relatively low face sheet porosity and a relatively high shield porosity. The shielded embodiment of the invention helps prevent a loss of acoustic admittance due to fluid grazing past the liner. Another embodiment that is not necessarily cooled, includes the resonator chamber, low porosity face sheet and high porosity shield, but no coolant plenum for bypassing coolant around the resonator chamber.

Abstract: A liner assembly includes a plurality of aligned passages providing a large open area combined with openings much smaller than a length of the passages. The plurality of passages are disposed parallel with each other and include an opening transverse to incident sound waves. The passages are separated by walls and are blocked at an end distal from the openings. Sound waves incident on a face of the liner enter the passages and are dissipated by viscous losses. Sound energy is further dissipated as thermal energy to the walls of the passages. The long narrow passages provide the desired visco-thermal losses for sound energy in a broad frequency range.

Abstract: A noise-absorbing device includes a substantially flat base and embossed and/or hollow elements each including at least one recess. This base reveals with the embossed and/or hollow elements, a configuration exhibiting a fractality zone of between 1 cm and 50 cm, of fractal dimension greater than 2.5 enabling the localization of the waves over the sound frequency range, in the vicinity of the elements.

Abstract: A liner assembly for an aircraft engine housing includes a noise attenuation structure that is covered by a face sheet. The face sheet covering the noise attenuation structure includes a surface having a plurality of circumferentially spaced apart acoustic energy absorption areas that are interspersed between a corresponding plurality of acoustic energy reflective areas. The acoustic energy reflective areas scatter higher order acoustic modes into a plurality of lower order modes. The difficult to attenuate lower order acoustic modes produced by the various acoustic energy cancel each other out to provide significant improvement in liner noise reduction efficiency.

Abstract: A duct liner assembly includes a noise attenuation layer for absorbing noise energy that is covered by a face sheet. The face sheet includes a seam that is covered by an acoustically active splice. The acoustically active splice includes a plurality of acoustic regions that provide for communication of noise energy to the noise attenuation layer to minimize creation of acoustically dead areas.

Abstract: A fan case assembly includes a noise attenuation layer that is covered by a face sheet. The face sheet includes a first plurality of openings. The noise attenuation layer includes a plurality of individual cells that are in communication with at least one of the first plurality of openings. Noise energy is communicated through the first plurality of openings into the individual cells and dissipated to reduce noise emissions. A seam in the face sheet is covered to protect the underlying noise attenuation layer from damage by a retainer. The retainer is bonded to the face sheet over the seam and includes a second plurality of holes that communicates noise energy through the retainer to the noise attenuation layer. Communication of noise energy through the retainer provides an acoustically active seam that aids in the dissipation of noise energy and thereby reduces the level of sound emitted from the engine.

Abstract: A passive acoustic liner system (50) for attenuating a sound field comprising, in acoustic series, a mode-scattering segment (48) and a sound-absorbing segment (40), wherein the mode scattering segment (48) provides a reactance between ?12 and ?2 ?c and the sound absorbing segment (40) provides a reactance between ?1 and 0 ?c thereby providing a reactance discontinuity such that mode-scattering of the sound field enables the sound-absorbing segment (48) to further absorb the scattered sound.

Abstract: An insulator dash (20) installed on the interior side surface side of a dash panel (10), comprising a single sound absorbing layer (21) formed of a fiber assembly or a laminated assembly having light and soft skin layers (22,23,26,27,28) laminated on the surface of sound absorbing layer (21), wherein, since the reflected noise reflected from the inner surface of an instrument panel (40) is taken again from the front surface side into the sound absorbing layer (21) for sound absorption in addition to the sound absorbing and shielding performance of the insulator dash (20), the sound absorbing performance in the instrument panel (40) can be increased, whereby the weight can be reduced and a rise of sound pressure in the instrument panel (40) can be abolishing a conventional sound shielding layer so as to increase a silentness in a cabin.

Abstract: An apparatus and method of making an improved sound reducing panel is disclosed suitable for use in an outdoor or a hazardous environment. The improved sound reducing panel comprises a water resistant sound absorbing member with a porous covering sheet overlaying a face surface of the sound absorbing member. A support frame is disposed about an outer perimeter of the sound absorbing member. An attachment secures the improved sound reducing panel to the support frame. In one embodiment, a sound blocking member is located adjacent to the sound absorbing member.

Abstract: Sound attenuating laminates, and methods of making the same, are provided. Heat is applied to a surface of a non-woven, fibrous layer of material to form a stratum of melted fibers having a density greater than that of the remainder of the fibrous layer. The density of the melted fibers is effective in attenuating noise traversing the fibrous layer of material. Upholstery material, such as carpeting, is attached to the surface of the heated fibrous layer. The fibrous layer and upholstery material are then subjected to compressive molding pressure to obtain a desired shape. The compressive molding pressure may further tune the sound attenuating properties of the fibrous layer by selectively changing the densities of portions of the fibrous layer.

Abstract: An assembly useful in reducing aircraft engine noise such as turbofan engine noise comprises: (a) a core portion comprising at least one entrance end and at least one exit end for the passage of acoustic energy therethrough; (b) a first member having an exterior face and an interior face, wherein the first member is adjacent to at least a part of the core portion, and the first member has a plurality of openings therein to permit the passage of acoustic energy therethrough; and (c) a second member having an exterior face and an interior face, wherein the interior face of the second member is adjacent to the core portion. The core portion may be a honeycomb acoustic structure, and the first member may be perforated to permit the passage of acoustic energy into and out of the conduit portion.

Abstract: A blast compression wave absorbing device comprises a container filled with gas or air under pressure below ambient pressure (under vacuum). The device is positioned close to the facility or structure being protected, in atmosphere or under water. When a blast compression wave reaches the device, in accordance with various embodiments of the invention, the container collapses, ruptures, or its interior is being connected to the environment through rupturable diaphragm or fast-actuating valve. The ambient air starts to fill the internals of the container generating a negative pressure wave, which interferes with blast compression wave and produces a resulting pressure wave with reduced pressure and impulse affecting the facility or structure to be protected.

Abstract: The present invention concerns an automotive protective mat (1), also known as throw in mat or protective mat. This mat comprises a microporous stiffening layer (2) (acoustical membrane). This layer may be composed of several sheets. The overall air flow resistance is between 500 Ns/m3–4000 Ns/m3. It is essential for this mat (1) that it is hydrophobic. In order to achieve an enhanced acoustical effectiveness a decoupling layer (6) is foreseen between the microporous stiffening layer (2) and the vehicle floor (8). This decoupling layer might be incorporated in the mat (1) or constituted by the underlaying carpet or sound absorber of the vehicle floor. Further layers or sheets such as adhesive layers, non skid layers, face fabrics or carpets and/or loft layers can be added to the claimed mat.

Abstract: An aircraft engine assembly is provided that is adapted to reduce noise produced by an engine included in the engine assembly. The engine assembly includes a nacelle having an inlet section and a main section that is houses the engine and fan assembly associated with the engine. The inlet section is coupled to the main section at a main bulkhead junction between the inlet section and the main section. A one piece annular acoustic panel is located within a recess in an internal wall of the nacelle. The annular acoustic panel extends from a forward portion of the inlet section to a forward portion of the main section such that the bulkhead is covered by the annular acoustic panel.

Abstract: An internal duct of an aircraft engine pod may include a fan and a tubular air intake having a first acoustic attenuation internal tubular piece. The first acoustic attenuation internal tubular piece is acoustically homogeneous, is of the resonator type, and has no internal assembly fish-plate. Additionally, the internal duct may include a tubular fan casing and a tubular transition part for connecting the air intake to the fan casing. An internal face of the tubular transition part is acoustically homogeneous also. Moreover, the internal face of the first acoustic attenuation internal tubular piece and the internal face of the tubular transition part are disposed in aerodynamic continuity.

Abstract: An enfolding sound barrier manifests a high effect of abating noise as compared with the conventional sound barrier and is capable of enhancing durability and field workability and securing a view of the environment satisfactorily. The enfolding sound barrier has a sidewall 13 or a different sidewall capable of being seen through and an enfolding body 1 which is constructed in an enfolding shape. The enfolding body 1 includes a bent member 2 furnished with a plurality of bent parts 2a and which is attached to the sidewall 13 for application to an express highway or railroad, or attached to the different sidewall for application to an ordinary road.

Abstract: A honeycomb acoustic unit is provided, the unit comprising first and second honeycomb layers, the layers being made of honeycomb core, each being formed by metallurgical bonds, and a deformable septum having two opposing sides, the first and second honeycomb layers being metallurgically bonded to the two opposing sides of the deformable septum.

Abstract: An acoustically resistive layer for an acoustic attenuation panel (22) forming a conduit in which there is an aerodynamic flow (18), adapted particularly for an aircraft turbo jet engine. The panel has at least one acoustically resistive layer (24), at least one porous structure (26) and a reflector (28) disposed opposite the incident wave. The acoustically resistive layer (24) is constituted by strips (30) disposed in the direction of the flow (18), interconnected by a plurality of splints (32) ensuring the absorption of force, particularly radially, the splints (32) having very small surfaces ensuring the continuity of the homogeneous character of the quantity of open surface of the acoustically resistive layer thus formed.

Abstract: The fine jet control type sound absorption system of this invention, aimed at absorbing low-frequency sound with both discrete frequency and broadband frequency to the same degree as already existing acoustic lining can do, is composed of two parts. One is a barrier wall covering an air space in which the concerning low-frequency sound propagates and having a multiplicity of small holes formed therein. The other is the means for causing a fine jet passing through these small holes into or out from the air space. This sound absorption system realizes a fine jet in the vicinity of the barrier wall for the purpose of canceling the sound inside the air space by means of the interference of the sound with the fine jets. Any of or a combination of shape of small holes, jet ejection angle or suction angle, amount of jet flow, thickness of a barrier wall back layer and air flow angle at which secondary air flows into the barrier wall back layer is selected.

Abstract: Tubular acoustic attenuation piece for an aircraft jet engine air intake. According to the invention, said tubular piece (1) is made up of shells (2) with a cellular core (5) assembled only by external fish plate strips (8), the facing edges (6) simply being edge faces of said shells (2) forming slots (9) between them.

Abstract: An acoustical barrier comprises a layer of molded firm-flexible foam that is generally configured to match the acoustical requirements in an environment and mounted against a sound-transmitting substrate and can have one or more areas of patterned recesses along a substrate-facing side or varying thickness tailored to the intensity of sound transmitted through the sound-transmitting substrate with or without a thin, impervious barrier layer overlying the foam layer.

Abstract: Aircraft engine pod with acoustic attenuation.

Abstract: Acoustic insulation barrier for railway lines, characterised in that it comprises, for each rail (10), two continuous arrays (18, 20) of sound-absorbing elements (22) positioned at opposite parts of the rail (10) and connected to the flange (12) of the rail (10).

Abstract: Tubular acoustic attenuation piece for an aircraft jet engine air intake.

Abstract: The object of the invention is an acoustically resistive layer for an acoustic attenuation panel (22) forming a conduit in which there is an aerodynamic flow (18), adapted particularly for an aircraft turbo jet engine, said panel comprising at least one acoustically resistive layer (24), at least one porous structure (26) and a reflector (28) disposed opposite the incident wave, characterized in that said acoustically resistive layer (24) is constituted by strips (30) disposed in the direction of said flow (18), interconnected by a plurality of splints (32) ensuring the absorption of force, particularly radially, said splints (32) having very small surfaces ensuring the continuity of the homogeneous character of the quantity of open surface of the acoustically resistive layer thus formed.

Abstract: Device for connecting two tubular pieces of an aircraft turbine engine.

Abstract: The present invention provides a sound barrier system 10 including a sound barrier panel 20 having a face skin panel 30 held in spaced relation from a back skin panel 40 by a filler material 50. Each sound barrier panel 20 is provided with a tongue and groove design that permits panels 20 to be stacked in an interlocking fashion without fastening hardware.

Abstract: An acoustic medium for temporary acoustic treatment of a room is formed from one or more continuous curtains, preferably, with pleated first and second major surfaces. Each pleated curtain preferably has one or more series of collapsible elongated tubular sections which form the pleats that make up the major surfaces of the curtain. Since the elongated tubular sections are collapsible, the curtain can be retracted by collapsing the elongated tubular sections and extended by opening the elongated tubular sections. The mat materials forming the elongated tubular sections and the pleated major surfaces of the curtain provide the curtain with an airflow resistance through the curtain, in a direction generally perpendicular to the planes containing the apexes of the pleats forming the first and second major surfaces of the curtain, that has the desired properties for absorbing or reflecting sound.

Abstract: A noise attenuation panel used to attenuate noise in aircraft engines includes a cellular core and a facing sheet formed with an array of holes. The holes are laser drilled to provide: (i) hole size variation over the facing sheet; (ii) non-circular hole cross section; (iii) polygonal hole cross section; (iv) hole locations not contiguous with walls of the cellular core; and (v) inclined holes passing through the facing sheet in a direction inclined to the normal to the facing sheet.

Abstract: A method is disclosed for testing a jet aircraft engine at a time when an actual wind direction differs from a prevailing wind direction. The method is conducted in a ground runup enclosure (GRE), typically comprising a rear wall, a pair of side walls attached to the rear walls and an open front side opposite the rear wall, the front side facing in a prevailing wind direction. The method comprises moving the aircraft into the GRE, aligning the aircraft so that the air inlet of its engine faces the actual wind direction, and running the engine up to full power to test its condition. The method of the present invention permits the GRE to be used under a variety of unfavourable wind conditions, thereby improving its usability.

Abstract: An acoustic absorptive splitter consisting of two absorptive faces separated by a single on-quarter wavelength cavity support is disclosed as an equal substitute for a multi-layered splitter containing a central septum. This construction takes advantage of the reflective properties of the absorptive face sheets to support standing waves in the tuning cavities and in the duct cross modes. The utilization of these design principles permits significant silencer size and weight reduction. It also permits reduced splitter manufacturing costs by elimination of two layers of materials, difficult internal bonding and improvements in quality.

Abstract: A vehicle seat cover is designed to facilitate acoustic energy absorption by forming in the cover an optimal size and arrangement of perforations based on a target noise frequency range, the perforations allowing the noise to pass through the cover into the interior structure of the seat where the acoustic energy is dissipated in the form of heat.

Abstract: A sound barrier wall system for reducing the transmission of noise into residential and commercially sensitive areas. The sound barrier wall system includes a partition member having a plurality of rib members and a rear wall, and a plurality of support members positioned about the distal ends of the partition member. The partition member includes an upper slot and a lower tongue for allowing interlocking with adjacent partition members. The plurality of rib members extending from the rear wall form a sound dampening surface that breaks up the sound waves and deflects the sound waves away from a residential area. A plurality of cavities preferably extend into the inner surface of the rear wall of the partition member for further increasing the sound dampening capabilities.

Abstract: A broadband noise barrier includes Helmholtz-type resonator cavities. The barrier has a core section made up of one or more layers of cellular cavities of varying sizes sandwiched between a substantially planar face section placed toward a noise source, and an impermeable, substantially planar base section placed away from the noise source. The face section has apertures of specified sizes to permit disturbed air from the noise source to interact with the cavities in the core section. The variable cavity sizes permit resonant interactions with selected frequencies commonly associated with traffic noise, thus providing broadband acoustic absorption. Since the performance of the system derives from the resonator configuration rather than the constitutive properties of the materials used, the structure requires neither special materials, unconventional manufacturing processes, nor thick, heavy panel structures.

Abstract: The fine jet control type sound absorption system of this invention, aimed at absorbing low-frequency sound with both discrete frequency and broadband frequency to the same degree as already existing acoustic lining can do, is composed of two parts. One is a barrier wall covering an air space in which the concerning low-frequency sound propagates and having a multiplicity of small holes formed therein. The other is the means for causing a fine jet passing through these small holes into or out from the air space. This sound absorption system realizes a fine jet in the vicinity of the barrier wall for the purpose of canceling the sound inside the air space by means of the interference of the sound with the fine jets. Any of or a combination of shape of small holes, jet ejection angle or suction angle, amount of jet flow, thickness of a barrier wall back layer and air flow angle at which secondary air flows into the barrier wall back layer is selected.

Abstract: A dual membered sound wall panel constructed of two pre-formed half-panels. The half-panels have an inner surface that contains a plurality of connectors around their periphery and an outer surface. The outer surface may be textured if desired. The half-panels are each of concrete material with an embedded layer of mesh re-bar. The half-panels are oriented so that their inner surfaces are facing each other and the embedded connectors on each face are secured to each other. Additionally, between the half-panels are contained multiple spacer plates.

Abstract: An aircraft engine run-up hangar comprises a building defining a test chamber capable of receiving an aircraft therein, an air inlet structure, and an exhaust structure. The air inlet structure is formed in a front end part of a roof structure corresponding to a front end part of the building, the exhaust structure is connected to a rear end part of the building and defines an exhaust passage extending obliquely upward from the back end of the building, and one or a plurality of current deflecting members are disposed near a lower end of the air inlet structure to deflect air currents flowing through the air inlet structure into the building toward an aircraft housed in the building. A current-straightening structure is incorporated into the air inlet structure. A current-straightening space is defined under the air inlet structure.

Abstract: The object of the invention is a process for the production of a panel (9) with a fitted acoustically resistive layer, of the type comprising at least one central core with porous structure bounded on one side by a structural layer covered with a porous acoustically resistive layer and, on the other side, by a total acoustical reflector, in which, successively, acoustically resistive strips are laid down to form said layer on a mold (M) shaped like the panel to be obtained, said structural layer is emplaced, said core of porous structure is emplaced, said total reflector is emplaced, then the mold (M) is withdrawn from the panel, characterized in that the course of laying down on the mold (M) the acoustically resistive layer, the porosity of this latter is locally adapted to correspond with the characteristics of the sonic wave at the point of impact, the correlation between characteristics and impact region being previously determined with the help of conventional acoustical techniques applied to a test pane

Abstract: This invention relates to a double layer acoustic liner for attenuating noise and consisting of a plurality of cells formed in a plate in a manner to form an array of resonators, and a fluid processing device and method incorporating same.

Abstract: This invention relates to an acoustic liner for attenuating noise and consisting of a plurality of cells formed in a plate in a manner to form an array of resonators, and a fluid processing device and method incorporating same.

Abstract: Noise reduction sandwich panel, notably for an aircraft turbojet engine.

Abstract: In the manufacture of a noise attenuation panel for an aeroengine nacelle an adhesive film is applied to a front face of a cellular component of the panel. The adhesive film is caused to reticulate to the ends of the walls of the cells at the front face of the cellular component. A perforate facing component of the panel is bonded to the front face of the cellular component by adhesive flow from the cell walls to the facing component. To avoid unpredictable adhesive flow giving rise to cosmetic spots on the front face of the facing component the two components are brought together with the interposition of an adhesive flow control sheet and the reticulated adhesive caused to bond the two components together by adhesive flow under the control of the adhesive flow control sheet.

Abstract: A structure and method for absorbing and shielding sound from a source of sound are disclosed having at least four layers including a first panel layer 2, a sound absorbing material layer 3, a first air layer 4 and a second panel layer 6, which are located in a sequence from a source of sound. The sound absorbing material layer 3 has a ventilating property.

Abstract: The present invention relates to a noise suppressor capable of reducing the noise of a fluid vented at high pressure and high mass flow rate from an industrial source, to the environmentally acceptable noise level. The invention combines two principles of dissipation of fluid stream energy: first, stream pressure is reduced by passing the stream through a swirler to split the stream into a number of smaller tangential streams which dissipate their energy along the spiral flow path due to friction; and next, the resulting streams pass through a tightly packed granular bed to reduce further the pressure and velocity of the exiting jet to atmospheric pressure and subsonic velocity, respectively. Such jet will generate much lower noise level, as compared to high pressure jet with cellular structure and supersonic velocity.

Abstract: The invention relates to a noise-protection wall-segment, for example for roads, motorways or railways and such like, said noise-protection wall-segment including transparent sheets, preferably a transparent plastic sheets, and means fixing the sheets. The transparent sheet is shaped around a perpendicular to the installation surface of the assembled noise-protection wall, the term ‘shaping’ being understood to mean vaulting and/or folding. Moreover, in the case of plastic sheets, preferably made of acrylic glass, threads of synthetic material can be embedded in the sheet which counteract splintering in the event of fracture and constitute a recognized bird impact protection device.