A muffler may include a thin plate mesh provided in an internal space of an inlet chamber formed at a side opposite to an outlet chamber of a muffler housing such that gas contained in exhaust fluid passes through the thin plate mesh by collision of the exhaust fluid against the thin plate mesh and water contained in the exhaust fluid is separated from the gas; a water movement guide fluidically-connected to the inlet chamber and the outlet chamber for allowing the water gathered at the front side of the thin plate mesh in the internal space of the inlet chamber to flow therein and move to the outlet chamber; and a muffler pipe connected to the inlet chamber and the outlet chamber for allowing the gas gathered at the rear side of the thin plate mesh in the internal space of the inlet chamber to move to the outlet chamber.

Disclosed is a silencer for fuel cell vehicles. The silencer for fuel cell vehicles includes a housing having an inlet configured to receive air and hydrogen flowing into the housing therethrough, an outlet, and a condensation water drain hole configured to discharge condensation water to the outside therethrough, a distribution plate disposed in the housing and having distribution holes to distribute air and hydrogen flowing into the housing, a rotary plate disposed in the housing closer to the outlet than the distribution plate, a motor connected to the rotary plate to rotate the rotary plate, and an anti-freezing unit extending from one end of the rotary plate to the condensation water drain hole.

In the present disclosure is proposed a novel sound attenuating element for, at least in part, providing adequate or preferably improved sound attenuating properties without excessively impeding flow while being susceptible to automated or machine assisted manufacturing or for providing the public with a useful alternative. The novel sound attenuating element is formed at least in part by an assembly of a plurality of components which are successively connected to each other, which each exhibit a curved shape, and which form at least one non-planar ruled surface when assembled.

A vehicle exhaust system includes a component housing defining an internal cavity and at least one exhaust gas treatment element positioned within the internal cavity. A resonator volume is connected in parallel with the internal cavity via at least one resonator element and insulating material is located within the resonator volume.

An exhaust system includes a housing comprising a first housing portion and a second housing portion separated by a common wall. The first housing portion has a first exhaust passage therethrough. The first exhaust passage has a first inlet receiving exhaust gasses from a turbocharger. The second housing portion has a second exhaust passage therethrough. The second exhaust passage has a second inlet receiving gasses from an exhaust bypass valve. The first passage and the second passage are non-intersecting within the housing.

A muffler includes an inner pipe and an outer pipe which, along with the inner pipe, forms a double-wall pipe. A cavity is provided between the inner and outer pipes. A first end of the double-wall pipe is closed between the inner and outer pipes, and a second end of the double-wall pipe has an opening between the inner and outer pipes. The cavity communicates with an exhaust channel via the opening. The cavity is formed as a result of the inner pipe being shaped in a manner such that a portion of an outer-circumferential surface of the inner pipe is positioned on an inner-circumferential side relative to a reference, the reference being a position of an outer-circumferential surface of the outer pipe.

To provide an air passage type silencer and an acoustic impedance change structure of which the absorbance is high, that suppresses generation of a wind noise, and that has a high sound attenuation effect in a low-frequency band. Provided is an acoustic impedance change structure through which a sound propagates, the acoustic impedance change structure including at least in this order: a first impedance matching region that is connected to an inlet portion and in which an acoustic impedance gradually decreases; an acoustic impedance constancy region; and an outlet portion, in which Z.sub.cham<Z.sub.in and Z.sub.cham<Z.sub.out are satisfied, where Z.sub.in is an acoustic impedance in the inlet portion, Z.sub.cham is an acoustic impedance in the acoustic impedance constancy region, and Z.sub.out is an acoustic impedance in the outlet portion, and a first terminal structure acoustically connected to the acoustic impedance constancy region is provided.

An exhaust gas purification device for a vehicle comprises a coil configured to generate an electromagnetic field, a magnetic flux concentrator, surrounding the coil and configured to conduct the electromagnetic field generated by the coil, and an exhaust gas purification substrate. The exhaust gas purification substrate comprises an upstream segment having an upstream section, and a downstream segment having a downstream section. The exhaust gas purification substrate further comprises at least one intermediate segment between the upstream segment and the downstream segment, the intermediate segment having a central section smaller than the upstream section and/or the downstream section.

A muffler may include a thin plate mesh provided in an internal space of an inlet chamber formed at a side opposite to an outlet chamber of a muffler housing such that gas contained in exhaust fluid passes through the thin plate mesh by collision of the exhaust fluid against the thin plate mesh and water contained in the exhaust fluid is separated from the gas; a water movement guide fluidically-connected to the inlet chamber and the outlet chamber for allowing the water gathered at the front side of the thin plate mesh in the internal space of the inlet chamber to flow therein and move to the outlet chamber; and a muffler pipe connected to the inlet chamber and the outlet chamber for allowing the gas gathered at the rear side of the thin plate mesh in the internal space of the inlet chamber to move to the outlet chamber.

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.