The phenomenon of resonance in a catalyst converter due to a flow of an exhaust gas is reduced without causing problems with vehicle layout, problems with manufacturing (higher manufacturing cost), or adverse influences on other facets of performance. An internal combustion engine includes an internal combustion engine main body having a fuel chamber formed in an interior, and a catalyst converter arranged in an exhaust flow channel of the internal combustion engine main body and provided with a catalyst for purifying the exhaust gas. The exhaust flow channel, which is upstream of the catalyst of the catalyst converter, is provided with a protuberance for disturbing the flow of the exhaust gas in the exhaust flow channel to reduce pressure pulsations of the exhaust gas.

A manifold system for an internal combustion engine, comprising a housing designed as a collecting manifold, which housing has two inlet openings and an outlet opening for connecting two outlets of an internal combustion engine to an exhaust gas system in regard to flow and at least one connection opening provided on the housing for connecting to an outer shell of a double-shell air-gap-insulated manifold, and comprising at least one air-gap-insulated manifold connected to the connection opening, which air-gap-insulated manifold has an inner shell having an inlet opening for connecting to an outlet of the internal combustion engine in regard to flow and having an outer shell, wherein all air-gap-insulated manifolds are completely formed from sheet metal and are structurally or geometrically identical and, on the housing, the size of a distance A2 between one of the two inlet openings and the outlet opening is between 30 mm and 300 mm or between 50 mm and 120 mm.

An exhaust mixer assembly includes a mixer housing, an inlet opening, an inlet plate, a support plate, a support plate opening, a conveying tube, an outlet plate, and an outlet plate opening. The mixer housing is coupled to the upstream housing. The inlet plate and the support plate define a first mixing chamber. The inlet opening is configured to receive exhaust from the upstream housing and deliver exhaust to the first mixing chamber. The support plate and the outlet plate define a second mixing chamber. The conveying tube is positioned in the second mixing chamber. The support plate opening is configured to receive treated exhaust from the first mixing chamber and deliver the treated exhaust to the second mixing chamber. The treated exhaust circumferentially flows through the second mixing chamber and through the conveying tube. The conveying tube delivers reductant to the outlet plate opening.

In an exhaust gas control apparatus for an internal combustion engine in which a catalytic converter is attached to an engine having a plurality of cylinders and a plurality of exhaust passages communicating with the plurality of cylinders, a diffusion portion that promotes a jet flow of a main flow of the exhaust gas flowing into the merging portion is provided at a merging portion connected to a downstream side of the exhaust passage. Further, on the inner wall of the merging portion facing the inlet of the exhaust gas provided in the exhaust passage, a dispersion face for three-dimensionally dispersing the main flow of the exhaust gas flowing linearly into the merging portion from the inlet is formed.

An exhaust mixer assembly includes a mixer housing, an inlet opening, an inlet plate, a support plate, a support plate opening, a conveying tube, an outlet plate, and an outlet plate opening. The mixer housing is coupled to the upstream housing. The inlet plate and the support plate define a first mixing chamber. The inlet opening is configured to receive exhaust from the upstream housing and deliver exhaust to the first mixing chamber. The support plate and the outlet plate define a second mixing chamber. The conveying tube is positioned in the second mixing chamber. The support plate opening is configured to receive treated exhaust from the first mixing chamber and deliver the treated exhaust to the second mixing chamber. The treated exhaust circumferentially flows through the second mixing chamber and through the conveying tube. The conveying tube delivers reductant to the outlet plate opening.

An exhaust duct assembly for conveying exhaust gases emanating from a combustion zone to atmosphere is disclosed. The assembly includes: an exhaust gas outlet for exhausting exhaust gas into the atmosphere; and an acoustic duct portion located upstream of the exhaust gas outlet, the acoustic duct portion having a peripheral wall defining a through-passage arranged and constructed to promote propagation of sound there-through. The acoustic duct portion has a length in a flow direction that is at least 50% of an average hydraulic diameter of the through-passage.

An exhaust mixer assembly includes a mixer housing, an inlet opening, an inlet plate, a support plate, a support plate opening, a conveying tube, an outlet plate, and an outlet plate opening. The mixer housing is coupled to the upstream housing. The inlet plate and the support plate define a first mixing chamber. The inlet opening is configured to receive exhaust from the upstream housing and deliver exhaust to the first mixing chamber. The support plate and the outlet plate define a second mixing chamber. The conveying tube is positioned in the second mixing chamber. The support plate opening is configured to receive treated exhaust from the first mixing chamber and deliver the treated exhaust to the second mixing chamber. The treated exhaust circumferentially flows through the second mixing chamber and through the conveying tube. The conveying tube delivers reductant to the outlet plate opening.