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.

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 engine exhaust device includes: a first catalyst; a second catalyst; and a tubular connecting member. The connecting member includes: a first opening; a second opening; and a bend connecting. A downstream end surface of the first catalyst is connected to the first opening, and an upstream end surface of the second catalyst is connected to the second opening. The downstream end surface and the upstream end surface form a dihedral angle within a range from 60 to 120 degrees. A part of the upstream end surface of the second catalyst includes an overlap that is close and opposed to a part of a surface of the first catalyst. The bend of the connecting member includes: a first wall; a second wall; and a connector. The first wall has a curve. The curvature radius of the first wall is greater than the predetermined curvature radius.

An exhaust muffler includes a first muffler section connected to an exhaust pipe and a second muffler section connected to the first muffler section. Exhaust gases delivered from the exhaust pipe are discharged from the first muffler section and the second muffler section out of the exhaust muffler. The first muffler section includes a tubular member made up of an inner pipe to which the exhaust pipe is connected and an outer pipe covering the inner pipe, and a connector connecting the tubular member and the second muffler section to each other. The first muffler section has a first expansion chamber defined therein between the inner pipe and the outer pipe. The inner pipe houses therein a valve for changing an amount of exhaust gases passing through the inner pipe. The first muffler section includes a curved portion that is curved vertically as viewed in side elevation of the vehicle. The exhaust muffler has a second expansion chamber defined in the second muffler section rearward and upward of the first muffler section, the second expansion chamber having a cross-sectional area larger than a cross-sectional area of the first expansion chamber. There is thus provided an exhaust device for an internal combustion engine, which includes a muffler compact in a longitudinal direction 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.

An engine exhaust device includes: a first catalyst; a second catalyst; and a connecting member shaped into a tube and forming a part of the exhaust path, and connecting the first catalyst to the second catalyst. A downstream end surface of the first catalyst and an upstream end surface of the second catalyst form a dihedral angle within a range from 60 degrees to 120 degrees. A part of the upstream end surface of the second catalyst is close to and faces a part of a side surface of the first catalyst. On a cross-section including a central axis of the first catalyst and being parallel to a central axis of a second catalyst, a length of the part of the side surface of the first catalyst is longer than or equal to 10% and shorter than 50% of an entire length of the first catalyst.

A mix box for an exhaust system of an internal combustion engine, the mix box being used to incorporate additives into an exhaust gas flow and including at least one inlet tube, at least one outlet tube and a housing for accommodating the inlet tube and the outlet tube, wherein: the housing delimits a volume of the mix box in relation to the surroundings; the inlet tube has an inflow section located inside the housing, which inflow section is provided with at least one inflow opening for introducing the exhaust gas into the housing; the outlet tube has a metering device designed as an injection nozzle at the end of the outlet tube and has an outflow section located inside the housing, which outflow section has a length (La) and is provided with at least one outflow opening for discharging the exhaust gas from the housing; a flow zone is provided between the inlet tube and the outlet tube and the flow zone, over at least 30% of its length (La), is free of flow guiding elements which deflect the flow in a circumferential direction and which have an outer face and an inner face inside the volume.

The disclosure relates to an exhaust gas cooling device for an internal combustion engine, having a housing which can be connected to an exhaust gas line of the internal combustion engine and has an axis of symmetry and having a Venturi assembly coupled to the housing for introducing exhaust gas and ambient air and having an outlet line emitting an exhaust gas-ambient air mixture into the environment, wherein: the Venturi assembly has a Venturi channel which can be coupled fluidically to the exhaust gas line and an inlet opening delimited by the Venturi channel and the exhaust gas line for ambient air; the Venturi channel is used to conduct an exhaust gas-ambient air mixture and opens, with the inlet opening, into a mixing chamber; the Venturi channel has an outlet opening and the outlet opening has an inflow opening, wherein the outlet opening and the inflow opening are spaced apart from one another; the Venturi channel and the outlet line, with the inflow opening, open into the housing.

An engine exhaust device includes: a first catalyst; a second catalyst; and a tubular connecting member. The connecting member includes: a first opening; a second opening; and a bend connecting. A downstream end surface of the first catalyst is connected to the first opening, and an upstream end surface of the second catalyst is connected to the second opening. The downstream end surface and the upstream end surface form a dihedral angle within a range from 60 to 120 degrees. A part of the upstream end surface of the second catalyst includes an overlap that is close and opposed to a part of a surface of the first catalyst. The bend of the connecting member includes: a first wall; a second wall; and a connector. The first wall has a curve. The curvature radius of the first wall is greater than the predetermined curvature radius.

A muffler for an exhaust system of an internal combustion engine includes a housing, a through pipe that conducts exhaust gas during operation of the muffler and is guided through the housing, and a branch pipe fluidically branching off from the through pipe within the housing. The branch pipe has an upstream end at the through pipe and ends freely and open at an end face with a downstream end within the housing. The branch pipe has a length from the upstream to the downstream end or up to a lateral recess which has a cross-sectional area which is greater than half a pipe cross-section of the branch pipe. The branch pipe has downstream perforations in a section from of the length as measured from the upstream end A total area of the downstream perforations is smaller than half the pipe cross-section of the branch pipe, and no perforations or upstream perforations have a total area of at most 10% of the pipe cross-section of the branch pipe being present in a section before of the length.