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 air intake coupling has at least one noise suppression hole formed therein. A gas-air mixer elbow is fluidly coupled to the air intake coupling. A burner box assembly is fluidly coupled to the gas-air mixer elbow via a gas-air plenum box. A heat-exchange tube has a first end that is fluidly coupled to the burner box assembly. A fan is fluidly coupled to a second end of the heat-exchange tube via a cold-end header box.

An air intake coupling has at least one noise suppression hole formed therein. A gas-air mixer elbow is fluidly coupled to the air intake coupling. A burner box assembly is fluidly coupled to the gas-air mixer elbow via a gas-air plenum box. A heat-exchange tube has a first end that is fluidly coupled to the burner box assembly. A fan is fluidly coupled to a second end of the heat-exchange tube via a cold-end header box.

The invention relates to the field of power engineering and can be used in heating systems, more particularly in water heaters or boilers, in disposal systems fueled by the combustion of associated gas, and in electrical energy generating systems. A pulse combustion apparatus comprises a combustion chamber 14, at least one resonant channel 28 connected to the combustion chamber 14, a device 15 for removing heat which is linked to the combustion chamber and to the resonant channel and which consists of at least one chamber and/or at least one tube for a heat-exchanging agent 16. A device for supplying air and combustible gas, which is connected to the combustion chamber 14, comprises at least one gaseous medium nonreturn valve 17 and at least one guard chamber 18 of said valve 17. The at least one gaseous medium nonreturn valve 17 is directly or indirectly linked to the device 15 for removing heat via a vibration isolator 19, 24.

An acoustic liner includes a first face sheet, a second face sheet spaced from the first face sheet, and a plurality of sidewalls extending between the first face sheet and the second face sheet. The plurality of sidewalls defines a plurality of cells. Each cell of the plurality of cells defines a cavity between the first face sheet and the second face sheet. A bulk absorber is disposed within at least one cell of the plurality of cells. The bulk absorber further defines the cavity of the at least one cell of the plurality of cells. The first face sheet defines a plurality of apertures extending through a thickness of the first face sheet. Each aperture of the plurality of apertures is aligned with a respective cell of the plurality of cells.

A hollow plank of a combustor liner defining a combustion chamber including an inner wall having a plurality of inner openings and one or more inner holes, an outer wall having one or more outer openings and a plurality of outer holes, a plurality of lateral walls coupled to the inner wall and the outer wall to define a cavity, and a partition wall connected to the plurality of lateral walls and dividing the cavity into a first sub-cavity and a second sub-cavity. The one or more outer openings communicate with the first sub-cavity and communicate through a plurality of tubes with the second sub-cavity. The plurality of inner openings communicate with the second sub-cavity and communicate with the first sub-cavity through one or more bypass tubes. The first sub-cavity or the second sub-cavity, or both, are frequency tuned to reduce combustion dynamic frequencies.

An acoustic liner includes a first face sheet, a second face sheet spaced from the first face sheet, and a plurality of sidewalls extending between the first face sheet and the second face sheet. The plurality of sidewalls defines a plurality of cells. Each cell of the plurality of cells defines a cavity between the first face sheet and the second face sheet. A bulk absorber is disposed within at least one cell of the plurality of cells. The bulk absorber further defines the cavity of the at least one cell of the plurality of cells. The first face sheet defines a plurality of apertures extending through a thickness of the first face sheet. Each aperture of the plurality of apertures is aligned with a respective cell of the plurality of cells.

A gas turbine engine may include a combustion section having a fuel nozzle, a swirler, and a ferrule configured to mount and center the fuel nozzle with the swirler. The combustion section may further include a damper on a cold side of the combustion section. The damper may have an acoustic cavity, a damper neck, and a cavity feed hole. The damper may operate as Helmholtz cavity to absorb a hydrodynamic or acoustic instability present in a region within the swirler.

An air intake coupling has at least one noise suppression hole formed therein. A gas-air mixer elbow is fluidly coupled to the air intake coupling. A burner box assembly is fluidly coupled to the gas-air mixer elbow via a gas-air plenum box. A heat-exchange tube has a first end that is fluidly coupled to the burner box assembly. A fan is fluidly coupled to a second end of the heat-exchange tube via a cold-end header box.

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.