A silencer insert (10) for a silencer of an exhaust system includes a first and a second partition wall (11, 12) and a connecting wall (13) arranged therebetween. The first partition wall (11) defines a first plane (E1), the second partition wall (12) defines a second plane (E2), and the connecting wall (13) defines a third plane (E3). At least one of the first partition wall, the second partition wall, and the connecting wall includes at least one perforated area (15). The connecting wall (13) is formed in one piece with the first partition wall (11) and the second partition wall (12). The first plane encloses with the second plane an angle of not more than 60°, the first plane and the second plane being particularly in parallel. A silencer is provided including a housing (1) receiving the silencer insert (10). A method is provided for manufacturing the silencer insert.

A thermal management assembly is provided for both removing heat and absorbing acoustic energy. The thermal management assembly includes a heat sink base component and a plurality of thermally conductive fins disposed in a sparsely-arranged array in thermal communication with the heat sink base component. Each fin defines a two-sided Helmholtz unit cell disposed in a periodic array extending from the heat sink base component. Each unit cell includes a lossy resonator and a lossless resonator. The lossy resonator includes a first chamber portion bounded by at least one first boundary wall defining a first chamber volume, and a first neck forming an opening in the first chamber portion. The lossless resonator includes a second chamber portion bounded by at least one second boundary wall defining a second chamber volume, and a second neck forming an opening in the second chamber portion.

Acoustic treatments for components of gas turbine engines are described. The acoustic treatments include an acoustic resonator having a backing chamber defining a respective volume and a neck arranged relative to the backing chamber and defining an opening, wherein the neck has a length and a cross-sectional area. The acoustic resonator cell satisfies the following relationships: (1) l/L=0.2-0.8, where l is a length of the neck and L is a depth of the backing chamber and (2) a/A=0.02-0.20, where a is a cross-sectional area of the neck and A is a cross-sectional area of the backing chamber.

A muffler may include a shell, first and second baffles, an inlet pipe, first and second outlet pipes, and a communication pipe. The first and second baffles cooperate with the shell to define first, second and third chambers. The first inlet pipe may extend through the shell and may provide exhaust gas to at least one of the first and second chambers. Exhaust gas in the first chamber exits the muffler through the first outlet pipe. Exhaust gas in the second chamber exits the muffler through the second outlet pipe. The communication pipe may include first, second and third openings. The first opening is in communication with the first chamber. The second opening is in communication with the second chamber. The third opening is in communication with the third chamber. The first and second chambers may be in communication with the third chamber through the communication pipe.

An annular resonator with a multiplicity of perforations for installation into a combustor arrangement of a static gas turbine installation, wherein the resonator is produced from refractory ceramic. A combustor arrangement for a gas turbine installation with a combustor unit, has a combustor, with a transfer line, which is arranged downstream of the combustor unit and which is designed to conduct hot gas generated by the combustor to a turbine, and with at least one resonator.

One aspect of the present disclosure provides an exhaust unit including a housing, a wall member, a catalyst, and a muffler chamber. The housing includes a feed inlet and a discharge outlet. The housing is configured such that an exhaust gas of an internal combustion engine is introduced from the feed inlet, and the exhaust gas is discharged from the discharge outlet. The wall member is disposed in the housing, and forms a cylindrical flow path that guides a flow of the exhaust gas introduced from the feed inlet to curve along an outer circumference of an interior of the housing. The catalyst is disposed in the flow path. The muffler chamber communicates with the flow path in a downstream side of the catalyst in the flow path. The wall member serves as a part of a wall that defines an inside and an outside of the muffler chamber.

An exhaust device includes a housing, first and second pipes, and a spacer. The first and second pipes are at least partially disposed within the housing. The first and second pipes include respective first and second surfaces. A portion of the second pipe is disposed inside the first pipe. The first and second surfaces cooperate to define an annular volume into which the spacer is disposed to prevent direct communication between the first and second pipes. One of the first and second pipes is fluidly connected to an exhaust gas inlet. The other of the first and second pipes is fluidly connected to an exhaust gas outlet. One of the first and second surfaces defines a radial indentation. The other of the first and second surfaces defines a radial protrusion. The spacer is disposed at least partially within the radial indentation and is in direct communication with the radial protrusion.

A soundproofing device for a transmission according to the present disclosure is provided to transmit the power of one or more prime movers (for example, internal combustion engine and electric motor). The soundproofing device includes a Helmholtz resonator including: a wall that forms a Helmholtz resonance chamber; and an opening formed in the wall so as to cause the Helmholtz resonance chamber to communicate with the outside of the Helmholtz resonance chamber. The wall includes a transmission case that accommodates the transmission and a housing of a component mounted on the transmission (for example, PCU housing). The Helmholtz resonance chamber is formed between the transmission case and the housing.

An apparatus and method are provided for a drone elimination muffler to attenuate drone exhibited by engine exhaust systems. The drone elimination muffler comprises a hollow canister having a length and a diameter, and a tuned port comprising a first end connected to the canister and a second end connected to the exhaust system. The canister operates in concert with the tuned port as a dampener configured to substantially attenuate exhaust drone, or resonance, at one or more frequencies of engine operation. A valve is configured to switch the drone elimination muffler between a closed state in which the exhaust system operates without acoustic influence due to the drone elimination muffler, and an open state in which the drone elimination muffler directly influences the acoustic properties of the exhaust system.

A flow path duct system for a propulsion system of an aircraft includes a base defining a flow surface. The base has an internal surface and an external surface. A plurality of perforations are formed through the base between the internal surface and the external surface. A plurality of supports define a plurality of cavities. The plurality of supports extend outwardly from the external surface of the of the base. One or more of the plurality of cavities are in fluid communication with the one or more of the plurality of perforations. A backing surface is secured to the plurality of supports. The plurality of supports are disposed between the base and the backing surface. The one or more of the plurality of cavities are in fluid communication with an internal volume defined by the internal surface of the base through the one or more of the plurality of perforations. The base, the plurality of supports, and the backing surface can be integrally formed together as a monolithic, load-bearing structure.