An internal combustion engine includes an exhaust conduit having an exhaust port fluidically coupled to ambient fluid and having an internal cross-sectional area and an engine cylinder fluidically coupled to the exhaust conduit. A fluidic amplifier is disposed within the exhaust conduit and is fluidically coupled to the engine cylinder. The amplifier is further fluidically coupled to a source of primary fluid and is configured to introduce the primary fluid and at least a portion of fluid from the engine cylinder to the exhaust port.

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.

A timbre scaled internal combustion exhaust system includes: an inlet collector including a single entrance duct at a first end of the collector in fluid communication with an exhaust flow from an internal combustion engine and an exit duct at a second end of the collector; a plurality of non-perforated parallel tuning tubes in fluid communication with the plurality of exit ducts of the inlet collector, the plurality of tuning tubes having lengths and diameters selected based on a desired note of the timbre scaled exhaust system; an outlet collector including a plurality of entrance ducts in fluid communication with the at least first and second tuning tubes and a single exit duct in fluid communication with an outlet of the exhaust system. The inlet collector splits the exhaust flow through the plurality of tuning tubes to create individual notes, and wherein the outlet collector combines the split exhaust flow to create a desired sound of internal combustion engine exhaust.

An apparatus and method for attenuating sound from an engine exhaust. The relative lengths of the expansion chambers and other components within the apparatus provide a quadruple tuning effect which attenuates sound over a wide frequency range. Attenuation at higher frequencies is also increased and extended by the use of acoustically lined internal baffle tubes inside the apparatus housing.

A mixer for an exhaust system of an internal combustion engine for mixing exhaust gas and reactant includes a mixing chamber, a reactant dispensing arrangement for dispensing reactant into the mixing chamber axially between an upstream mixer wall and a downstream mixer wall, an inlet opening arrangement in the upstream mixer wall, an outlet opening arrangement in the downstream mixer wall, a flow guiding arrangement arranged between the upstream mixer wall and the downstream mixer wall, wherein the flow guiding arrangement provides a first flow path leading from the inlet opening arrangement to the outlet opening arrangement and a second flow path leading from the inlet opening arrangement to the outlet opening arrangement, wherein each flow path has at least two flow channels leading from the inlet opening arrangement to the outlet opening arrangement.

A sound bypass device configured to transmit engine-generated sound pulses from an engine to a sound outlet whilst preventing flow of gases to the sound outlet, the sound bypass device comprising: an input tube configured to conduct the engine-generated sound pulses from the engine; and a sound transmission device connected to the input tube at a first end and to the sound outlet at a second end, the sound transmission device comprising: a first volume connected to the first end, a second volume connected to the second end, and a flexible diaphragm separating the first volume from the second volume and configured to transfer variations in pressure in the first volume to the second volume; wherein the first volume has a cross-sectional area that is greater at the diaphragm than at the first end and the second volume has a cross-sectional area that is greater at the diaphragm than at the second end.

A flow guide and a method therein, including dividing by a divider a mixing chamber to input and output sides; supporting a mixing tube in the mixing chamber, receiving exhaust gas by an intake section from the input side; guiding the received exhaust gas by a swirl guide to flow inside the mixing tube towards the second end as a rotating and advancing main flow; mounting a reactant doser by a reactant doser mount such that when in use, it provides reactant to a dosing section; guiding exhaust gas through the divider by the mixing tube; receiving at least most of the rotating and advancing exhaust gas flow by the dosing section; providing a stem guide around the doser when mounted facing the rotating flow, and defining by the stem guide a central opening surrounding the doser when mounted; and guiding, using a passage structure of the stem guide, a side flow out of the rotating flow to a carrier flow around the doser via the central opening.

An exhaust gas system for an internal combustion engine includes a first exhaust gas line leading into a first muffler; a second exhaust gas line arranged fluidly parallel to the first exhaust gas line and leading into a second muffler, wherein the first and second exhaust gas lines are respectively connected upstream of the first and second muffler at a branch to a common exhaust gas feed line; a control valve arranged in the first exhaust gas line upstream of the first muffler; and a damping device fluidly arranged between the branch and the control valve and adapted for damping exhaust gas resonance vibrations.

An exhaust device includes left and right exhaust pipes and mufflers connected to a downstream side of the left and right exhaust pipes. The pair of left and right exhaust pipes respectively includes a merging portion. A catalyst is provided to the merging portion respectively. The pair of left and right exhaust pipes respectively includes, on a downstream side of the catalyst, a branching portion that has one side thereof extending to the muffler and the other side thereof extending to a connecting pipe. An oxygen sensor is provided to one side on a downstream side of the pair of left and right branching portions.

A heat-resistant body has a cavity for exhaust gas, which is open at opposite ends. The body has first wall portions, each of which delimits a first portion of the cavity. Each first wall portion has an outer region and an inner region which has planar protrusions which each extend from the outside region inward into the associated first cavity portion, the planar protrusions tapering along the longitudinal extent in their width directed perpendicularly to the longitudinal extent and being mutually laterally spaced. Each planar protrusion of a first wall portion is rotated or shifted relative to a planar protrusion of an adjacent first wall portion. The body has second wall portions, each of which delimits a second portion of the cavity and is disposed between two adjacent first wall portions. The cross-sectional area of each second cavity portion is larger than the cross-sectional area of each first cavity portion.