Abstract: An acoustic liner for a gas turbine engine includes an acoustic panel that is curved about a central axis. The acoustic panel includes a support backing, a face sheet, and a cellular structure disposed between the support backing and the face sheet. The face sheet has elongated slots that extend along respective slot centerlines in the plane of the face sheet. The slot centerlines are sloped at oblique angles to the central axis.

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 vane for use in a gas turbine engine includes an airfoil having a suction side and a pressure side, and a transpirational flow acoustic liner disposed in the airfoil. The liner includes a face sheet defining a portion of an outer surface of the airfoil and having a plurality of first apertures, a segmented member coupled to the face sheet, and a backing sheet coupled to the segmented member the segmented member such that the segmented member is positioned between the face sheet and the backing sheet. The segmented member includes a plurality of chambers in fluid communication with the outer surface via the plurality of first apertures. The backing sheet has a plurality of second apertures.

Abstract: Systems and methods are presented for dampening noise in a rotating machine having a rotatable shaft defining an axis of rotation. An acoustic panel assembly may comprise an annular casing, a hook, and an acoustic panel carried by the hook. The acoustic panel comprises a radially inner skin, a radially outer skin, and an acoustic treatment member having a plurality of walls extending between the radially inner skin and the radially outer skin thereby defining a plurality of radially oriented cells. A portion of the cells adjacent a first axial edge of the acoustic panel are filled with a reinforcement material and shaped to form a lip having sufficient strength to support a portion of the acoustic panel. The panel is positioned so that the lip is axially and radially retained by the hook.

Abstract: An exhaust sound control system for vehicles includes an exhaust valve device that controls the volume of exhaust sound by controlling the amount of exhaust gas flowing through a muffler. In a sporty driving mode, exhaust sound is permitted to be transferred to the interior of the vehicle, and in a silent driving mode, the volume of exhaust sound transferred to the interior the vehicle is minimized. The volume of exhaust sound transferred to the interior of the vehicle is varied depending on the driving mode desired by the driver. Accordingly, the sensorial quality related to sound generated while driving is improved.

Abstract: A gas turbine engine has a resonator ring that is formed by two circumferentially extending rings. The first and second circumferentially extending rings have located within them baffles. Both the first ring and the second ring are able to mitigate acoustic frequencies generated by the gas turbine engine.

Abstract: A method of manufacturing a fan case assembly for a gas turbine engine, the fan case assembly comprising a fan case and a fan liner, wherein the method comprises: providing a mounting ring configured to extend about an inner circumference of the fan case; providing a gasket at an axial end of the mounting ring, wherein the gasket extends around the inner circumference of the fan case; providing the fan liner at the axial end of the mounting ring with the gasket, wherein the fan liner extends around the inner circumference of the fan case; and heating the fan case assembly so as to cure a resin provided between the fan case and fan liner, wherein the heating causes the mounting ring to expand radially relative to the fan case such that the gasket is brought into engagement with the fan case and unwanted migration of resin away from between the fan case and fan liner is restricted.

Abstract: An assembly including two juxtaposed acoustic panels. Resistive faces of the acoustic panels are in the continuation of one another. A first resistive face extends as far as the first end wall of a first panel. The first end wall is in contact with a second end wall of a second panel in the region of the first resistive face and of the second resistive face. A connecting piece is interposed between the first end wall and the second end wall over a part of the length thereof so that the connecting piece does not extend as far as the first and second resistive faces. That makes it possible to form an acoustic cladding that is continuous, exhibiting no non-acoustic zone or reduced-acoustic zone at the junction between the acoustic panels of which it is formed. A nacelle of an aircraft propulsion unit is one application.

Abstract: The disclosure relates to a flow deflector for a discharge valve system of a double flow turbomachine compressor. The flow deflector comprises a wall provided with a plurality of ejection channels positioned to discharge a discharge air flow. The ejection channels are arranged in rows along aligned directions, substantially parallel to an axial plane of the deflector. The ejection channels of each row are oriented at a defined angle between a normal line to the wall and axes of the ejection channels, and decreasing between an upstream edge and a downstream edge of the wall, as defined according to the direction of movement of the air flow.

Abstract: A sound attenuation device includes an acoustic panel having a first end and a second end spaced from the first end. The first end is configured for attachment to a first mount and the second end is configured for attachment to a second mount. The acoustic panel comprises a permeable skin and a septum, the septum having a length extending between the first end and the second end.

Abstract: An intake duct for an internal combustion engine includes a tubular side wall. The side wall includes a first molded body and a second molded body that are separate from each other in a circumferential direction of the side wall. The first molded body includes first and second joints. The second molded body includes first and second joints. The first and second joints of the first molded body and the first and second joints of the second molded body are joined to each other. The first molded body includes a rib protruding toward the second molded body and extending in an axial direction of the side wall. The rib is located inward from the first and second joints of the first molded body. The second molded body includes an accommodation recess that accommodates the rib. The accommodation recess is located outward from the rib.

Abstract: An acoustic liner can include a support layer having a set of partitioned cavities with open faces, a first facing sheet and second facing sheet both having perforations and operably coupled to the support layer such that the facing sheets overlie and close the open faces, and an aerogel layer operably coupled to the second facing sheet.

Abstract: A ground testing device for a turbomachine, including an aircraft engine (12) extending axially from an air inlet to a nozzle, a shroud (20) having an axis of revolution (A) and surrounding at least partially the engine (12) so as to create an annular air flow between the engine (12) and the shroud (20) when the engine (12) is in operation, and a framework (22) allowing the shroud (20) to be supported.

Abstract: Casings and methods for manufacturing casings are provided. For example, a casing defining radial, axial, and circumferential directions is provided. The casing comprises an annular inner wall and an annular outer wall, each extending along the axial direction, with the outer wall radially spaced apart from the inner wall. The casing also comprises an auxetic structure extending from the inner wall to the outer wall and including a plurality of lattice elements. Each lattice element extends circumferentially and radially from the inner to the outer wall, and the lattice elements are axially spaced apart from one another. The auxetic structure may define at least one aperture for fluid flow from one portion to another of the auxetic structure and/or may be configured to vary the thermal characteristics of the casing along the axial direction. The casing may be integrally formed as a single monolithic component, e.g., by additive manufacturing.

Abstract: A bypass valve for a combustor, including: a housing; an opening in the housing; a pneumatically actuated component within the housing; a passage coupling the opening in the housing and a duct of the combustor; a chamber formed by the housing and the pneumatically actuated component, the chamber containing a volume of air; and a control valve for controlling a pressure within the chamber to selectively displace the pneumatically actuated component to open and close the passage.

Abstract: A method includes assembling a silencer baffle configured to mount in a fluid conduit along a fluid flow path, where assembling the silencer baffle includes coupling together a plurality of baffle sections via mating interlock structures.

Abstract: A containment structure for surrounding a rotatable machine includes a double-walled inner shell having a forward end, an aft end, and a substantially cylindrical body extending therebetween. The inner shell includes an inner wall at least partially surrounding a bladed portion of the bladed rotor, and an outer portion that branches radially outward from the inner wall. The containment structure also includes a substantially cylindrical back sheet coupled to the outer portion and disposed radially outward of the inner wall.

Abstract: A system includes a silencer baffle which mounts in a fluid conduit along a fluid flow path. The silencer baffle includes a first baffle section having first and second baffle portions which couple together laterally about a support structure extending between opposite sides of the fluid conduit.

Abstract: Disclosed is flutter damper including a first cavity having a radially inner side in fluid communication with a flow path, and a second cavity having a radially inner side in fluid communication with a radially outer side of the first cavity, and the flutter damper having an impedance characteristic at one or more target frequencies defined as ftarget=fS,ND+?·ND wherein fS,ND is a resonance frequency corresponding to a structural mode of a rotating component, ND is a nodal diameter count of the structural mode, and ? is a rotational speed of the rotating component, and wherein the flutter damper has the following impedance characteristic at the one or more targeted frequencies R?2?c ?3?c?X??0.6?c wherein R is the real part of the impedance characteristic, X is the imaginary part of the impedance characteristic, ? is air density, and c is speed of sound.

Abstract: A flutter damper is disclosed, which includes a chamber configured to fluidly communicate with a gas flow, the chamber being filled with an open celled foam bulk damper, and wherein the chamber is configured for peak acoustical energy absorption at a frequency range that is associated with one or more fan flutter modes.

Abstract: A combustor including a first perforated layer including a first opening having a first diameter, wherein the first opening is configured to receive a flow of fluid including a fuel and air mixture; and impart a first rotational instability to the flow of fluid that is dependent on the first diameter; and a second perforated layer surrounding a combustion area, wherein the second perforated later includes a second opening having a second diameter, and wherein the second layer is located between the first layer and the combustion area.

Abstract: Various embodiments relate to an air intake duct. The duct includes louvers forming an air inlet to a housing. Each louver includes an inlet section and an angled section, the angled section inclined with respect to the inlet section. The duct includes the housing positioned downstream of the louvers in an air flow direction. The housing includes a drain configured to permit separated water from an intake air passing through the louvers and into the housing to be drained from the housing. The duct includes an inner inlet duct that provides the intake air to a component. The inner inlet duct extends into the housing and positioned downstream of the louvers in the air flow direction. The inlet duct extends above the drain by a distance thereby forming a well in the housing between a top of the inner inlet duct and the drain.

Abstract: A gas ejection duct with acoustic treatment provided with at least one wall referred to as an “acoustic” wall for coming into contact with the gas. The acoustic wall comprises an inner skin and an outer skin that are spaced apart at least in part by a space, the acoustic wall including at least one internal mesh in the space, the mesh defining a plurality of cavities. Each cavity has the shape of a parallelepiped, each mesh extending longitudinally in a direction referred to as the “fabrication” direction that presents an acute angle greater than or equal to a predetermined angle relative to a horizontal plane, each of the inner and outer skins presenting an acute angle of inclination greater than or equal to the at least one predetermined angle relative to the horizontal plane.

Abstract: A method is provided of bonding a first component to a second component. The method includes: locating the first component against the second component to form an interface between the components, a curable adhesive being provided at the interface; locating a pressurizable, fluid-filled bladder against the first component such that the first component is sandwiched between the second component and the bladder; locating a backing member against the bladder such that the bladder is sandwiched between the backing member and the first component; pressurizing the bladder such that a consolidating pressure is exerted by the bladder on the first component to conform the first component to the second component; and curing the adhesive while the first component is conformed to the second component by the consolidating pressure.

Abstract: Noise attenuation units are disclosed that are connectable in a system as part of a fluid flow path. Such units include a housing defining an internal cavity and having a first port and a second port each connectable to a fluid flow path and in fluid communication with one another through the internal cavity, and a noise attenuating member seated in the internal cavity of the housing within the flow of the fluid communication between the first port and the second port. The noise attenuating member enables the fluid communication between the first port and the second port to flow through the noise attenuating member.

Abstract: A surface cooler for turbomachines includes an inner layer and an outer layer disposed adjacent to the inner layer and including a metal foam, a carbon foam, or a combination thereof, wherein the metal foam, the carbon foam or a combination thereof is configured to augment heat transfer and enhance acoustic absorption. Further, the outer layer includes a plurality of fins, wherein the plurality of fins are configured to augment heat transfer and enhance acoustic absorption, and wherein the plurality of fins includes metal foam, a carbon foam, or a combination thereof.

Abstract: The invention relates to an extension (30) of an intermediate frame for an aircraft turbine engine, that will project downstream from an outer ring of the intermediate frame, this extension comprising a downstream annular connecting part (64) preferably forming an annular groove (66) open radially outwards, into which the nacelle cowls will fit (38), the end (64) comprising at least one first angular sector (76b). According to the invention, the extension comprises a body (77) made from a single piece comprising a junction ring (74) and at least one second angular sector (76a) of said downstream annular connecting part (64), the first angular sector being added onto the extension body (77).

Abstract: A nacelle is provided for an aircraft propulsion system. The nacelle may include an outer barrel and an active laminar flow control system. The active laminar flow control system may include a plurality of suction sources and a plurality of arrays of perforations in the outer barrel. The active laminar flow control system may be configured with a plurality of zones. Each of the zones may include a respective one of the suction sources which is fluidly coupled with a respective one of the arrays of perforations in the outer barrel.

Abstract: A thrust reverser track beam is disclosed. The thrust reverser track beam may comprise a recess defined by a reception surface and/or a perimeter surface surrounding the reception surface and extending away from the reception surface, wherein the reception surface and the perimeter surface bound a recess that is configured to receive a noise suppressing structure. The thrust reverser track beam may further comprise the noise suppressing structure. The recess is generally triangular in shape and may extend away from a plane. The noise suppressing structure may be generally triangular in shape and may extend away from a plane. The noise suppressing structure may be coupled within the recess of the track beam and/or to the track beam.

Abstract: An existing acoustic honeycomb panel having a radius of curvature is cut into segments that have longitudinal and lateral sides that extend between the edges of the honeycomb. The segments are bonded together along their longitudinal or lateral sides to form a segmented acoustic honeycomb in which the radius of curvature is different from the radius of curvature of the original acoustic honeycomb panel. The shape of the longitudinal or lateral sides of the segments and the thickness of the adhesive bond can be controlled to provide segmented acoustic honeycomb panels that are tightly curved and which are suitable for use in demanding noise damping applications, such as jet engine nacelles.

Abstract: A low pressure turbine, in particular for a gas turbine engine, extends along an axis, has an annular conduit for guiding a gas flow and is provided with a plurality of stator arrays of blades and a plurality of rotor arrays of blades; the last of the stator arrays, considering the advancement direction of the gas flow, has a plurality of blades, which define a plurality of spaces between them in circumferential direction; the spaces are split by respective splitters into a radially outer conduit and into a radially inner conduit; the radial position of the splitters is in the neighborhood of a radial reference position such that at least one acoustic mode is of the cut-on type in the radially inner conduit.

Abstract: A hybrid structure comprises a metallic built-up sandwich structure, and a monolithic superplastic formed and diffusion bonded structure joined to the built-up sandwich structure.

Abstract: A turbine engine casing, including a substantially cylindrical wall and a single-piece annular panel for acoustic insulation mounted radially inside the wall, is provided. The panel includes a radially outer annular surface fitted with upstream and downstream first projecting members respectively arranged in the upstream and downstream portions of the radially outer annular surface of the panel. The wall includes a radially inner annular surface fitted with upstream and downstream second projecting members that are releasably fastened respectively to the upstream and downstream first projecting members.

Abstract: An aircraft auxiliary power unit sound attenuation apparatus includes a perforated body having a center aperture through which exhaust fluid passes, a backing member outwardly offset from the perforated body, a plurality of connecting members coupling the perforated body to the backing member to form a locally reacting sound attenuation member having a plurality of channels spanning outwardly from the perforated body to the backing member, and a bulk absorber disposed in each of the plurality of channels where the bulk absorber is in fluid communication with the exhaust fluid, where the locally reacting sound attenuation member is in fluid communication with an auxiliary power unit of an aircraft so that the plurality of channels are oriented in a direction crossing a pressure drop direction of an exhaust fluid flow passing through the center aperture and each channel circumscribes the center aperture.

Abstract: A silencer panel includes an acoustic absorbing material; and an enclosure surrounding the acoustic absorbing material. The enclosure includes at least one plastic, perforated side wall.

Abstract: The application provides a thermo-acoustic protection structure for a rotating machine. The thermo-acoustic protection structure includes an upper wall and a parallel lower wall, and between them is placed at least one acoustic absorbent material. The upper wall and the lower wall being connected with at least one connecting element of an extended form. The connecting element presenting, in transverse section, at least one portion, curved or rectilinear, that is non-orthogonal to the two walls. A length of the connecting element between the upper wall and the lower wall is greater than a distance between the upper wall and the lower wall. The connecting element further presents in transverse section at least one edge.

Abstract: A wall structure is provided with noise damping insulation properties, for an air intake manifold of a gas turbine. The wall structure includes a first structure for mechanically supporting an outer sheet, which separates the spaces on both sides of the wall in an airtight manner, and further includes a second structure for establishing noise damping insulation between the spaces on both sides of the wall. The second structure is secured to the first structure. A gas turbine including the wall structure is also provided.

Abstract: The present disclosure provides a method for manufacturing a sound attenuation panel having a first cellular core structure and a second cellular core structure joined in a junction area (J). The method includes: a) a joining edge of the first cellular core structure is joined to a corresponding joining edge of the second cellular core structure, thereby forming the junction area; b) the first cellular core structure and the second cellular core structure are placed between an inner skin and an outer skin of the panel. In particular, the method further has a step prior to step a), in which one junction reinforcement is inserted between the joining edge of the first cellular core structure and the corresponding joining edge of the second cellular core structure in the junction area.

Abstract: An intake silencer device is described herein. The intake silencer device includes an outer housing and a plurality of sequential arranged expansion chambers separated by walls. The intake silencer device further includes an inner tube positioned in each of the sequential chambers, each of the inner tubes including an opening providing fluidic communication between an interior of the tube and the corresponding expansion chamber, a size of the openings increasing in size sequentially in a downstream direction.

Abstract: An aircraft nacelle including a pipe (32), a peripheral wall (34), a lip (36), and a front frame (38) connecting the peripheral wall (34) and the pipe (32) and forming with the lip (36) a space (50) in which the hot air that is provided for frost treatment can circulate, with the pipe (32) including a coating (44) for the composite material acoustic treatment, is characterized in that the nacelle includes at least one element (52) made of a heat-conducting material inserted between the lip (36) and the pipe (32) ensuring the continuity of the aerodynamic surfaces of the lip (36) and the pipe (32) and the propagation of heat from the space (50) toward the rear of the nacelle, whereby the at least one element (52) includes a coating (54) for acoustic treatment that is made of a heat-resistant material.

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: An adsorption unit for combustion gas of an internal combustion engine has an adsorption housing having a chamber section with an inner wall. An adsorption element disposed in the adsorption housing is made of a gas-permeable adsorption medium that is formed to a hollow body and encloses an interior of the adsorption element. The hollow body has opposed open ends. A main flow passage extends through the hollow body and the combustion gas flows in main flow direction through the hollow body. The adsorption element has an exterior circumferential side facing away from the interior and delimiting together with the inner wall of the chamber section a bypass chamber surrounding the absorption element outwardly. In the main flow direction, the bypass chamber has a downstream end that is closed off and an upstream end that has at least one bypass opening that communicates with the main flow passage.

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: In a silencer, holes are disposed in one row with intervals to each other along one direction, holes forming the one row are disposed in a plurality of rows in a direction perpendicular to the one direction, and positions of the holes in adjacent rows are shifted in the one direction and disposed in a zigzag pattern. A disposition interval of the holes of an outer edge hole row forming one row in at least two sides opposite to each other in the silencing porous plate is set to be larger than a disposition interval of the holes of a row inside the outer edge hole row.

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: An air intake structure for a turbojet engine nacelle includes a substantially annular main structure having an internal wall, an external wall and an air intake lip structure connecting the external and internal walls upstream. The air intake structure also includes a first acoustic attenuation structure which has a holed acoustic skin, a cellular core and a solid rear skin with which the internal wall is equipped, and a second acoustic attenuation structure having a similar architecture fitted to a part of the air intake lip substantially near a junction with the internal wall. The rear skin of the first acoustic attenuation structure is aligned with the rear skin of the second acoustic attenuation structure, both of rear skins being structural.

Abstract: The invention relates to a primary cowl for a turbofan comprising a primary body generating a primary stream to be ejected through a primary nozzle, and a secondary body generating a secondary stream to be ejected through a secondary nozzle, the primary cowl being shaped so as to be positioned downstream from the primary body and to define, on the inside of the turbofan, the path followed by the primary stream downstream from the primary nozzle and, on the outside, the path followed by the secondary stream downstream from the secondary nozzle. The primary cowl comprises a coupling to a system for supplying a pressurised gas and at least one perforation for injecting the pressurised gas, through the perforation, into the secondary stream. The primary cowl preferably comprises a ring which has perforations and which is rotated about the axis of rotation of the turbofan.

Abstract: An air pillow system for an air intake tract includes a plurality of inwardly extending ribs arranged in a distally spaced arrangement and defining a plurality of peripherally closed air pillow pockets. Each pocket has an open end opening towards an airflow stream to be guided. Each rib is configured with an inwardly extending length selected to correlate with a boundary of a low-loss airflow glide path. The air pillows operate to guide the airflow stream along the low-loss airflow glide path with reduced airflow stream turbulence and airflow pressure loss.

Abstract: A method for manufacturing a sound absorber, the outer wall of which is provided with a plurality of recesses, with funnel-like cone elements each being assigned to the recesses inside the sound absorber, said cone elements having a larger opening facing radially outwards and a smaller opening facing radially inwards, with adjacent cone elements each being provided on a strip-shaped first carrier band, with cup elements being provided radially on the inside relative to the cone elements, and each cup element receiving one cone element, with adjacent cup elements each being provided on a strip-shaped first carrier band, with the first carrier bands being arranged adjacently in a first direction, and the second carrier bands being arranged adjacently in a second direction, with the directions crossing each other and the carrier bands being joined to one another and to the outer wall to form a rigid body.

Abstract: A silencer for an auxiliary power unit of an aircraft includes an inlet, an outlet, a housing, and a flow channel of a porous material, arranged in the housing. Between the housing and the flow channel an intermediate space is created, which space is divided by at least one outer partition into outer cells arranged around the flow channel. A central body includes a casing that is permeable to gas at least in some regions and that is arranged in the interior of the silencer. The central body includes inner partitions dividing the central body into inner cells. The resonance frequency of the inner cells corresponds to the natural frequency of the first radial mode in a channel formed between the central body and the inner surface of the inlet. In this manner particularly good sound attenuation is achieved with a compact installation space of a silencer.