Abstract: An acoustic damper arrangement for a combustor which has an inner liner configured for use at a first temperature during operation and an outer liner configured for operation at a second temperature lower than the first temperature during operation is disclosed, the acoustic damper arrangement comprising: a plurality of flexible sheets; and at least one hollow body having an interior volume, each of said at least one hollow body being fixed to one of the plurality of flexible sheets, wherein the acoustic damper arrangement is configured to be fixed to both the inner liner and the outer liner such that the interior volume of the at least one hollow body is in communication with a chamber formed by the inner liner, and the plurality of flexible sheets accommodate expansion and contraction of the inner liner relative to the outer liner.

Abstract: In one embodiment, a system includes a variable geometry resonator configured to couple to a fluid path upstream from a combustor of a turbine engine. The variable geometry resonator is configured to dampen pressure oscillations in the fluid path and the combustor.

Abstract: An exhaust system for exhausting multiple cylinders of a small engine, wherein the exhaust system includes a plurality of exhaust units is described herein. Each exhaust unit of the exhaust system is operatively and fluidly connected to a separate cylinder of the small engine such that the exhaust gases from each cylinder remain separated as they pass through different exhaust units of the exhaust system. The exhaust system includes at least two exhaust units, and of the exhaust units is separated by an inner chamber wall that is shared by adjacent exhaust units yet prevents fluid communication between the adjacent exhaust units.

Abstract: A noise reducer for reducing engine noise of a jet engine having a central axis and a main exhaust nozzle. The noise reducer includes a tubular member having ports at a distal end and is aligned along the central axis. The ports are located in the exhaust stream of the engine outside the main exhaust nozzle. A gaseous flow is injected into the exhaust stream from the ports in an angled direction with respect to the central axis.

Abstract: A gas turbine engine exhaust mixer has a plurality of circumferentially distributed alternating inner and outer lobes. The outer lobes protrude into the annular bypass passage of the engine, whereas the inner lobes protrude into the main gas path passage of the engine. The inner and outer lobes respectively define alternating troughs and crest with radial interconnecting walls therebetween. The mixer has a jagged trailing edge including a plurality of tabs extending from each radial wall between the troughs and the crests.

Abstract: A volute for a radial turbomachine is proposed. The turbomachine includes a radial compressor or a radial turbine. The volute is in particular for a radial compressor. The volute has a substantially annular cavity which is delimited at least by a first radial side surface. At least one substantially annularly circumferential groove is formed in the side surface.

Abstract: An example auxiliary power unit (APU) exhaust silencer includes cooling features to protect the outer skin and other components from heat generated by gases passing through an exhaust duct. Cooling air flow through a cooling air passage in thermal contact with the exhaust silencer carries heat away from other nearby components and the aircraft skin.

Abstract: Disclosed is a method for producing a modified aircraft bypass turbojet engine having reduced sound output, in which the method is based on modifying an initial configuration of a rear portion of the turbojet engine to produce a modified rear portion of the turbojet engine. The modified rear portion includes a modified outer convex rear part shaped with a modified concave inner rear part that delimits an intermediate space beyond an initial cold stream outlet orifice. The intermediate space has a thickness at least equal to the thickness (E) of a sound deadening coating, which is placed in the intermediate space.

Abstract: The invention relates to a two-stroke engine for an engine-driven tool, including a muffler, especially for a manually operated engine-driven tool such as a maintenance device for gardens or green spaces, for a hand-held tool such as a chain saw, a hand-held circular saw or an angle grinder or for a small motorcycle, a boat engine and the like, wherein the flow channel between the muffler inlet and the first chamber is formed so as to promote flow such that the exhaust gas entering the muffler inlet mainly enters the first chamber due to its inertia and once the first chamber is full flows back again. The counterpressure of the exhaust gas is produced at a point in time in which the piston releases the outlet and the fuel-air mixture at least for its most part has entered the combustion chamber through the at least one transfer passage.

Abstract: A sound attenuating heat exchanger for an internal combustion engine includes a housing, a barrier wall and a fin. The housing includes an exhaust inlet, an exhaust outlet, a coolant inlet and a coolant outlet. The exhaust inlet is connected to the exhaust outlet by an exhaust flow passage. The coolant inlet is connected to the coolant outlet by a coolant flow passage. The barrier wall fluidly separates the exhaust flow passage from the coolant flow passage. The fin extends from the barrier wall into the exhaust flow passage, and includes a resonator adapted to attenuate sound waves traveling through exhaust gas within the exhaust flow passage. The barrier wall and the fins are adapted to exchange heat energy between the exhaust gas flowing through the exhaust flow passage and coolant flowing through the coolant flow passage.

Abstract: A method for designing and manufacturing an acoustic liner for jet aircraft engines employing a spherical wedge-shaped physical model employing conservation of mass and momentum. The model has three dimensions and four empirical parameters: the location of the far-field driving acoustic pressure; the location wherein the acoustic-mean-flow is pumped into and out of the resonator volume; and two parameters that describe the acoustic-mean flow rates pumped into and out of the resonator.

Abstract: An acoustic panel is provided that includes at least one cellular core arranged between at least an internal skin and an external skin, wherein the external skin incorporates at least one fastener able to collaborate in a disconnectable fashion with a complementary fastener associated with a structure to which it is to be attached.

Abstract: Honeycomb sections are bonded together with seams made up of an adhesive that is carried by a honeycomb seam support or 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 dampening structures.

Abstract: A resonance damper for damping acoustic oscillations within a combustor housing of a gas turbine engine is provided. The resonance damper includes a container, an opening, and a pipe. The container is configured to be attached to an interior wall of the combustor housing and has a cavity. The opening is provided on the container. The pipe is rigidly connected to the opening to define the resonance damper with the cavity.

Abstract: An exhaust silencer assembly for use with an auxiliary power unit includes an eductor and a discharge pipe. The eductor is disposed downstream of the auxiliary power unit and has an entrance opening at a forward axial end thereof. The entrance opening is configured to receive exhaust airflow from the auxiliary power unit. The discharge pipe extends from the auxiliary power unit and communicates with the exhaust silencer assembly downstream of the entrance opening of the eductor.

Abstract: A nacelle assembly for a bypass gas turbine engine includes a variable area fan nozzle having a first fan nacelle section and a second fan nacelle section. The variable area fan nozzle is in communication with a fan bypass flow path, the first fan nacelle section defines an intermittent trailing edge which defines a multiple of ports and the second fan nacelle section defines a multiple of doors, each of the multiple of doors match each of the multiple of ports such that a fan nacelle trailing edge is continuous when the second fan nacelle section is selectively translated to a closed position relative to the first fan nacelle section.

Abstract: A one-piece soundproofing panel which is attached within an circumferential air blower casing of a turbomachine, with an axis, in which circulates an airflow from upstream to downstream, is disclosed. The panel includes a circumferential rigid seat with a longitudinal cylindrical part, arranged to axially extend with respect to the axis A of the turbomachine, having an outside surface, intended to come to extend facing with an internal surface of the air blower casing, and an internal surface to which is applied a soundproofing coating; and an annular fastening flange, formed at the upstream end of the longitudinal cylindrical part, radially outwardly extending, the fastening flange being arranged to cooperate with a fastening flange of the air blower casing.

Abstract: A method for assembling a turbine engine including a compressor is disclosed. The method includes coupling an inlet including an inertial particle separator (IPS) and a first surface that is defined using a segment angle, to a gas turbine engine, and coupling the first surface substantially flush against a fuselage of an aircraft to reduce drag.

Abstract: High bleed flow muffling systems are disclosed. Example muffling devices according to at least some aspects of the present disclosure may include a first orifice plate and a second orifice plate at least partially defining a plenum arranged to receive the flow of a compressible fluid. The first orifice plate and the second orifice plate may be arranged to produce cross-impinging flow such that flow through the orifices of the first orifice plate into the plenum is directed at the wall of the second orifice plate and such that flow through the orifices of the second orifice plate is directed at the wall of the first orifice plate. Some example embodiments may include an inlet flow restrictor disposed upstream of the first and second orifice plates.

Abstract: Nozzle exit configurations and associated systems and methods are disclosed. An aircraft system in accordance with one embodiment includes a jet engine exhaust nozzle having an internal flow surface and an exit aperture, with the exit aperture having a perimeter that includes multiple projections extending in an aft direction. Aft portions of individual neighboring projections are spaced apart from each other by a gap, and a geometric feature of the multiple can change in a monotonic manner along at least a portion of the perimeter.

Abstract: An acoustic damper is fixed to a vibration source to be provided along an outer surface of the vibration source, forms a passage that takes in air vibration generated by the vibration source, and is provided with an acoustic portion having a partition member closing the downstream side of the passage with respect to the propagation of the air vibration to serve as resistance against the air vibration, in which the acoustic portion allows air vibration to propagate in a reverse direction, and has partition members arranged so as to serve as resistance against the air vibration in respective directions. This allows to prevent from generating stress due to pressure fluctuation caused when reducing vibration, and to achieve a relatively compact size.

Abstract: An object is to provide a combustor that requires a small mounting space for an acoustic damper, that can achieve size reduction, and that can improve the ease of maintenance. A combustor (5) of the present invention includes a combustion cylinder (19) that defines a combustion area (23) therein and an acoustic damper (31) that has a damper cover having an acoustic-damper resonance space communicating with the combustion area (23). The damper cover is provided along the combustion cylinder (19) so as to extend in a direction intersecting an axial direction (L) of the combustion cylinder (19).

Abstract: A gas-turbine exhaust cone has an outer wall with a plurality of recesses, a honeycomb-structured layer arranged at the inside of the outer wall and extending along said inside of the outer wall, an inner wall connected to the honeycomb structure and extending essentially parallel to the outer wall, and at least one annular chamber centered on a central axis and adjoining the inner wall. The inner wall has passage recesses connecting the area of the honeycomb structure to the annular chamber, with the annular chamber being subdivided in the circumferential direction by at least one partition wall into several chambers. The partition wall is made from a sheetmetal-like material and has a plurality of raised and/or recessed areas in a uniform arrangement formed by shaping of the sheetmetal-like material.

Abstract: An acoustic dampener comprises a first wall, orifice plate, and second wall. The first wall separates a first fluid source from a second fluid source. The first wall has a hole for allowing fluid communication between the first fluid source and a first cavity of the acoustic dampener. The office plate separates the first cavity of the acoustic dampener from a second cavity of the acoustic dampener. The second wall has a hole for allowing fluid communication between the first cavity of the acoustic dampener in the second cavity of the acoustic dampener. The second wall separates the second cavity of the acoustic dampener from the second fluid source. The second wall has a hole for allowing fluid communication between the second cavity of the acoustic dampener and the second fluid source. In one embodiment, the acoustic dampener is formed in a combustion chamber liner of a gas turbine engine.

Abstract: Methods and devices for increasing the sound attenuation properties of a noise suppression device are provided. Various embodiments include sound-attenuating cavities with improved sound capturing openings. In some embodiments, the sound capturing openings include holes surrounded by projections. In other embodiments, the sound capturing openings include angled slats. Embodiments also include sound capturing devices that include the improved sound capturing openings, such as silencers, vent hoods, barrier walls, air exchanges, and air intake and exhaust ducts.

Abstract: A resonator system for a turbine engine can improve acoustic performance and cooling effectiveness. During engine operation, a combustor liner exhibits alternating hot and cold regions in the circumferential direction corresponding to the non-uniform temperature distribution of the combustion flame. Accordingly, high flow resonators are formed with the liner in substantial alignment with the hot regions of the fluid flow within the liner, and low flow resonators are formed with the liner in substantial alignment with cold regions of the fluid flow within the liner. As a result, appropriate amounts of cooling can be provided to the liner so that cooling air usage is optimized. Alternatively or in addition, the liner can include two or more rows of resonators, which can provide an enhanced acoustic damping response. The resonators in the first row can be aligned with or offset from the resonators in the second row.

Abstract: One-piece soundproofing panel intended to be attached within an circumferential air blower casing of a turbomachine, comprising an axis, in which circulates an airflow from upstream to downstream, the panel including a circumferential rigid seat comprising a longitudinal cylindrical part, arranged to axially extend with respect to the axis A of the turbomachine, comprising an outside surface, intended to come to extend facing with an internal surface of the air blower casing, and an internal surface to which is applied a soundproofing coating and an annular fastening flange, formed at the upstream end of the longitudinal cylindrical part, radially outwardly extending, the fastening flange being arranged to cooperate with a fastening flange of the air blower casing.

Abstract: An apparatus and method for inducing waves within a container arranged to permit a through-flow of fluid flowing generally from an inlet of the container to an exit of the container, wherein the container has wave inducing means located at the exit of the container, the wave inducing means being operable to vary the area of the exit thereby inducing waves within the container. The apparatus may form part of a combustor test rig.

Abstract: A gas-turbine exhaust cone has an outer wall with a plurality of recesses, a honeycomb-structured layer arranged at the inside of the outer wall and extending along said inside of the outer wall, an inner wall connected to the honeycomb structure and extending essentially parallel to the outer wall, and at least one annular chamber centered on a central axis and adjoining the inner wall. The inner wall has passage recesses connecting the area of the honeycomb structure to the annular chamber, with the annular chamber being subdivided in the circumferential direction by at least one partition wall into several chambers. The partition wall is made from a sheetmetal-like material and has a plurality of raised and/or recessed areas in a uniform arrangement formed by shaping of the sheetmetal-like material.

Abstract: A method for processing at least one surface element wherein at least one layer of a deformable, medium-tight material is respectively attached to each side of the surface element, inserts the surface element and attached deformable layers between at least two molding tool parts and applies a pressure to at least one area of a surface section of the inserted surface element in response to a predetermined shaping temperature by introducing a medium between one of the deformable layers and a first molding tool part. The pressure acts directly against the deformable layer so that the surface element together with the deformable layers is shaped into at least one adjacent cavity of a second molding tool part due to the pressure created. A possibility of molding surface elements, which can currently not be shaped via gas pressure, into complex geometries, namely into spatially bent geometries, is created with this method.

Abstract: A gas-turbine exhaust cone includes a cone shaped outside cone 1 closed in a flow direction, an inside cone 2 arranged in the outside cone 1 over at least part of the length of the exhaust cone, with the inside cone 2 being connected to the outside cone 1 via at least one helical partition wall 3, thereby forming an interspace 4 between the outside cone 1 and the inside cone 2. The interspace 4 is connected to inlet openings 5 at its inflow side and opens at an exit side 6 towards an interior 7 of the outside cone 1. A dampening element 8 is arranged in the outside cone 1 adjacent to the exit side 6 of the interspace 4.

Abstract: A tube for moving gas between an entry end into which gas is introduced and an exit end through which gas exits the tube, the tube comprising a plurality of adjoining adjacent? guides, each guide comprising an outer half of a smoothly-curved, modified torus, and an outer rigid tube wall. Each guide forms an internal cavity with a cavity mouth opening into an inner portion of the tube, the cavities shaped such that a vortex forms within each of the cavities as gas passes through the tube, and the flow of fluid in the tube is unidirectional and axial from the entry end to the exit end.

Abstract: An exhaust silencer assembly includes an exhaust duct and an exhaust silencer. The exhaust silencer is disposed about the exhaust duct and has a plurality of solid baffles and at least one perforated baffle The exhaust silencer assembly is disposed downstream of an auxiliary power unit and at least partially attenuates the downstream noise of the combustion gases that result from operation of the auxiliary power unit. In one embodiment, at least one of the plurality of solid baffles is disposed to extend axially between generally radially extending solid baffles, perforated baffle(s), or partially perforated baffles. The axially extending solid baffle allows for cavity depth variation in the silencer to optimize tuning of particular frequencies from the auxiliary power unit.

Abstract: The soundproofed exhaust duct for a turbine engine comprises a perforated inner shell defining a flow passage, and a solid outer shell, the inner and outer shells defining between them a space that is closed at the upstream and downstream ends of said space. A core extends between the inner and outer shells at a distance therefrom, and contains at least one sound energy dissipating layer made up of hollow beads that are held against one another. A frame with upstream and downstream portions connected together by longitudinal members supports the core and partitions it into a plurality of boxes that are filled with hollow beads that are held between perforated textures, the frame being secured to the outer shell and/or to the inner shell via at least one of its upstream and downstream portions.

Abstract: An example core nacelle for a gas turbine engine includes a core cowl positioned adjacent to an inner duct boundary of a fan bypass passage having an associated cross-sectional area. The core cowl includes at least one groove that is selectively exposed to change the cross-sectional area.

Abstract: A gas turbine engine comprising a fan section, a compressor, a combustor and a turbine, includes a nacelle having an inner nacelle surface defining an inlet duct designed to reduce an inlet duct area of the inlet duct to increase acoustic attenuation. The gas turbine engine also includes a spinner, disposed forward of the fan section, that includes features to increase acoustic attenuation. In one embodiment of the present invention, the nacelle includes a nacelle contoured surface protruding radially inward from the inner nacelle surface to reduce the inlet duct area. In a further embodiment of the present invention, the spinner includes a spinner contoured surface for reducing the inlet duct area. In other embodiments, the nacelle and/or the spinner include an inflatable bladder, a SMA actuator, a fluidic actuator, or a combination thereof, selectively activated to increase acoustic attenuation during certain conditions of an aircraft.

Abstract: A resonator is provided, having an adaptable resonator frequency for absorbing sound generated by a gas stream of a gas turbine. The resonator includes a neck section, a chamber and a deformable element being deformable under influence of a change of a gas turbine temperature of the gas stream. The shape of the deformable element is predetermined with respect to a respective gas turbine temperature. The neck section and the chamber form a volume of the resonator. The neck section forms a passage coupling the volume with the gas turbine. The deformable element is thermally coupled to the gas turbine in such a way that the shape of the deformable element depends on the respective gas turbine temperature. The deformable element forms a spiral and is installed to the neck section in such a way that an effective diameter of the neck section depends on the gas turbine temperature.

Abstract: In order to improve an arrangement of a silencer on a combustion motor, whereby the silencer has a connection piece which with an end area adjoins an outlet in the cylinder of the combustion motor forms a flow connection between a combustion chamber of the combustion motor and the silencer in such a way a disturbance-free flow connection between a combustion chamber in the cylinder and the silencer is made possible, and more particularly to simplify the mounting of a silencer on the cylinder of a combustion motor, the internal diameter of the end area is made larger than the internal diameter of the outlet.

Abstract: Methods integrated tailcone muffler (ITM) is provided for minimizing noise generated while discharging pressurized air from one or more aircraft gas turbine engines. The ITM comprises a tail cone defining a conical backing cavity, the conical backing cavity having a large forward end and a narrow aft end and a porous exhaust liner with a first end and a second end, the first end coupled to an oil cooler eductor discharge plenum of a first gas turbine engine of the one or more gas turbine engines and a second end discharging to atmosphere via the narrow aft end of the conical backing cavity.

Abstract: Buzz saw noise propagates through inlet of aviation engine at high power settings. An inlet of aviation engine with blowing slot blowing air grazing over surface of buzz saw lining at speeds higher than inlet mean air flow speed for buzz saw noise control.

Abstract: A silencer for a gas turbine includes a first duct portion; a second duct portion connected to the first duct portion, the first and second duct portions forming an elbow region at the connection; and a plurality of elbow shaped vanes provided in the elbow region. The plurality of elbow shaped vanes have equal lengths and are spaced equally apart.

Abstract: A method for reducing noise emissions of an aircraft engine (3) having a gas turbine (7), includes providing a hot gas layer underneath at least one noise-emitting area of the aircraft engine.

Abstract: A sonic absorption device for an air pipeline of an aircraft, which sonic absorption device comprises at least one curved pipe section whose respective interior wall is clad with a sound absorption material, wherein within the curved pipe section at least one air guidance means is arranged for a flow optimization, wherein for further weight-neutral sound absorption the air guidance means arranged within the curved pipe section comprises a microperforation on at least one side surface.

Abstract: An exhaust system composed of a plurality of components for an internal combustion engine for connecting to a manifold, the exhaust system includes at least one, first section, which is provided indirectly or directly after the manifold in the flow direction, arid a second section, which is directly adjacent thereto in the flow direction, wherein the two sections are connected to each other by a mechanical decoupling element. The resonant oscillations in the range above 600 Hz are to be attenuated in the exhaust system by more than 15 dB and, at the same time, the exhaust system is to be sufficiently rigid and self-supporting and designed to be lastingly gas-tight. For this purpose, a single-walled arid self-supporting acoustic insulating element is integrated in the exhaust system in the flow direction upstream of, or in, the first section.

Abstract: In a method for adjusting a Helmholtz resonator (10), in which a resonator volume (11) is connected to a space (13) to be provided with damping along an axis (29) via a constriction (12) having an acoustic impedance, the acoustic impedance of the constriction (12) is altered in order to adjust the Helmholtz resonator (10).

Abstract: A radiated sound reducing structure that reduces radiated sound generated in a pipe through which gas passes includes a first pipe and a second pipe that is arranged inside the first pipe and has, on an outer peripheral surface, a linear contact portion that is in linear contact with a portion of an inner peripheral surface of the first pipe. Also, a radiated sound reducing structure in a pipe through which gas passes includes a first pipe and a second pipe formed in a pseudo-cylindrical concave polyhedral shell that is arranged inside the first pipe and has, on an outer peripheral surface, a point contact portion, that is in point contact with a portion of the inner peripheral surface of the first pipe.

Abstract: An aircraft configuration that may reduce the level of roaring jet exhaust noise, infrared radiation, sonic boom, or combination thereof directed towards the ground from an aircraft in flight. The aircraft's nacelles are mounted to the aircraft higher than the wings, with substantially vertical stabilizers outboard of the outermost engine. Noise shifting means are provided such as, for each nacelle, primary chevrons at the core nozzle, secondary chevrons at the fan nozzle, a partial bypass mixer, a long duct full flow mixer, or a combination thereof to provide a shift in spectrum distribution of jet exhaust noise from lower to higher frequency. Variable geometry chevrons may be used with increased immersion to provide such a shift just during noise-restricted portions of an aircraft flight profile. The aircraft aerodynamic structural surfaces serve as noise shielding barriers that more effectively block or redirect the frequency shifted noise up and away from communities.

Abstract: Disclosed is a muffler (1, 21, 41) integrated with a catalytic converter bed (9, 32, 52) including a polymeric muffler body (2, 22, 42), an inlet pipe (3, 23, 43) in flow communication with engine exhaust, said inlet pipe connected to a first body mounting adapter (5, 25, 45) so as to hold the inlet pipe a heat insulating distance from said polymeric muffler body, said inlet pipe in flow communication with an inlet of said catalytic converter bed (9, 32, 52), and a perforated exhaust pipe (4, 34, 44) in flow communication with an outlet of the catalytic converter bed, said perforated exhaust pipe mounted on a second body mounting adapter (6, 26, 56) so as to hold the perforated exhaust pipe a heat insulating distance from the polymeric muffler body; said inlet pipe and said perforated exhaust pipe holding said catalytic converter bed a heat insulating distance from the polymeric muffler body, said first body mounting adapter, polymeric muffler body, and second body mounting adapter forming a sealed internal c

Abstract: An end cap for a fuel injector of a turbine engine is disclosed. The end cap includes an annular first surface including a plurality of perforations. The annular first surface is exposed to a combustion chamber of the turbine engine. The end cap is coupled to an end face of the fuel injector to define an enclosed cavity. The enclosed cavity and the plurality of perforations form an array of Helmholtz resonators.

Abstract: A gas-turbine exhaust cone includes a cone shaped outside cone 1 closed in a flow direction, an inside cone 2 arranged in the outside cone 1 over at least part of the length of the exhaust cone, with the inside cone 2 being connected to the outside cone 1 via at least one helical partition wall 3, thereby forming an interspace 4 between the outside cone 1 and the inside cone 2. The interspace 4 is connected to inlet openings 5 at its inflow side and opens at an exit side 6 towards an interior 7 of the outside cone 1. A dampening element 8 is arranged in the outside cone 1 adjacent to the exit side 6 of the interspace 4.