An exhaust device (108) for a vehicle is provided. The exhaust device (108) includes an outer shell (202), an inlet (206) to receive exhaust gases, an outlet (208), an inner shell (204) received within the outer shell (202), a pair of partition walls (216) and a Helmholtz neck (220). The inner shell (204) defines an inner volume (210). A plurality of first circumferential openings (212) extending through the inner shell (204) fluidly communicates the inlet (206) with the inner volume (210). A plurality of second circumferential openings (214) extending through the inner shell (204) fluidly communicates the outlet (208) with the inner volume (210). The pair of partition walls (216) is disposed between the inner shell (204) and the outer shell (202). The pair of partition walls (216), the inner shell (204) and the outer shell (202) define a Helmholtz chamber (218) therebetween. The partition walls (216) seal the Helmholtz chamber (218) from the inlet (206) and the outlet (208). The Helmholtz neck (220) is disposed on the inner shell (204) or one of the pair of partition walls (216).

An exhaust device (108) for a vehicle is provided. The exhaust device (108) includes an outer shell (202), an inlet (206) to receive exhaust gases, an outlet (208), an inner shell (204) received within the outer shell (202), a pair of partition walls (216) and a Helmholtz neck (220). The inner shell (204) defines an inner volume (210). A plurality of first circumferential openings (212) extending through the inner shell (204) fluidly communicates the inlet (206) with the inner volume (210). A plurality of second circumferential openings (214) extending through the inner shell (204) fluidly communicates the outlet (208) with the inner volume (210). The pair of partition walls (216) is disposed between the inner shell (204) and the outer shell (202). The pair of partition walls (216), the inner shell (204) and the outer shell (202) define a Helmholtz chamber (218) therebetween. The partition walls (216) seal the Helmholtz chamber (218) from the inlet (206) and the outlet (208). The Helmholtz neck (220) is disposed on the inner shell (204) or one of the pair of partition walls (216).

An acoustic damper includes a low porosity layer section and a housing. The low porosity layer section is formed in a liner of a gas turbine combustor and has an arrangement of elongated generally S-shaped slots formed therein. The housing has a plurality of feed apertures. The housing is coupled to the low porosity layer section thereby defining a cavity such that air outside the housing is configured to flow through the apertures and through the elongated generally S-shaped slots in the low porosity layer section, thereby transforming acoustic energy into thermal energy and aiding in providing an acoustic dampening effect for the gas turbine combustor during operation thereof.

An acoustic damper includes a low porosity layer section and a housing. The low porosity layer section is formed in a liner of a gas turbine combustor and has an arrangement of elongated generally S-shaped slots formed therein. The housing has a plurality of feed apertures. The housing is coupled to the low porosity layer section thereby defining a cavity such that air outside the housing is configured to flow through the apertures and through the elongated generally S-shaped slots in the low porosity layer section, thereby transforming acoustic energy into thermal energy and aiding in providing an acoustic dampening effect for the gas turbine combustor during operation thereof.

A vacuum clear and an electric motor module (100) therefor are provided. The electric motor module (100) includes an outer casing (1) provided with an air inlet (10) at a front side thereof and an air outlet (11) at a rear side thereof; an electric motor assembly (2) arranged in the outer casing (1), and cooperating with the outer casing (1) to define an air passage in communication with the air inlet (10) and the air outlet (11); and a silencer (3) arranged at the air inlet (10), defining at least one resonant cavity therein, and the at least one resonant cavity having a side wall provided with a throat in communication with the resonant cavity.

A vacuum clear and an electric motor module (100) therefor are provided. The electric motor module (100) includes an outer casing (1) provided with an air inlet (10) at a front side thereof and an air outlet (11) at a rear side thereof; an electric motor assembly (2) arranged in the outer casing (1), and cooperating with the outer casing (1) to define an air passage in communication with the air inlet (10) and the air outlet (11); and a silencer (3) arranged at the air inlet (10), defining at least one resonant cavity therein, and the at least one resonant cavity having a side wall provided with a throat in communication with the resonant cavity.

Provided is a flow modification component for use with a muffler, which can be a Helmholtz resonator muffler, a side branch muffler, or a Y-pipe. The flow modification component includes a porous plate adapted for incorporation into a passage to a sound muffling portion connected to a through passage pipe of the muffler or Y-pipe. One or more openings are formed on the porous plate to allow low frequency acoustic waves to pass through into the passage to the sound muffling portion while reducing large-scale turbulent eddies that produce undesirable resonant tones within the aperture tube to small-scale turbulent eddies. The openings having sufficient porosity such that the resulting sound frequency is determined by size, shape, number, and spacing of the openings. The flow modification component can also include a dissipative material component in an internal port passage of the muffler to further reduce resonant tones.

Provided is a flow modification component for use with a muffler, which can be a Helmholtz resonator muffler, a side branch muffler, or a Y-pipe. The flow modification component includes a porous plate adapted for incorporation into a passage to a sound muffling portion connected to a through passage pipe of the muffler or Y-pipe. One or more openings are formed on the porous plate to allow low frequency acoustic waves to pass through into the passage to the sound muffling portion while reducing large-scale turbulent eddies that produce undesirable resonant tones within the aperture tube to small-scale turbulent eddies. The openings having sufficient porosity such that the resulting sound frequency is determined by size, shape, number, and spacing of the openings. The flow modification component can also include a dissipative material component in an internal port passage of the muffler to further reduce resonant tones.

The present invention aims to provide a sound-absorbing material having sound absorption performance with an average sound absorption coefficient of 0.65 or more in the frequency domain of 800 to 2000 Hz. The present invention relates to a sound-absorbing material including: a fiber layer including a plurality of holes open to a surface thereof and having a thickness of 3 mm or more; and an inorganic material layer formed on the surface of the fiber layer, the holes being blind holes each penetrating through the inorganic material layer and having a bottom inside the fiber layer.

A vehicle exhaust system includes an exhaust component comprising a wall having an outer surface and an inner surface that defines an internal exhaust component cavity. At least one hole is formed in the exhaust component to extend through the wall of the exhaust component from the outer surface to the inner surface. A membrane is configured to overlap the at least one hole, wherein the membrane is moveable relative to the wall in response to pressure fluctuations.