One aspect of the present disclosure provides a muffler including an exhaust pipe and a space forming member. The exhaust pipe has a cylindrical shape having a flow passage inside through which exhaust gas passes. The space forming member forms closed spaces between itself and the exhaust pipe, the closed spaces being branched from the flow passage and adjacent to the flow passage. Each of the closed spaces and the flow passage communicate with one another via a single communication hole.

A compact slip-in spark arrester having an interior shell (125) with a circular cross-section changing in diameter along its axial length which is axially aligned between an inlet cap member (115) and an outlet cap member (145). The tubular center section (130) of the interior shell (125) containing a centrifugal whirling means to remove any particulate matter from the exhaust flow by means of centrifugal force or deflection and trapping the particulate matter in an outer chamber (155) between the interior shell (125) and existing silencer shell (100).

A damping device, in particular for damping or preventing pressure impacts, like pulsations, in hydraulic supply circuits, comprising a damping housing (1) which surrounds a damping chamber and has at least one fluid inlet (13) and a fluid outlet (15) and a damping tube (21; 51) located in the flow path between the damping inlet and outlet, said damping tube having at least one branch opening (29; 73, 75, 77, 79, 81) passing through the tube wall and leading to a Helmholtz volume (27; 53, 55, 57, 59, 61) inside of the damping housing (1) for forming a Helmholtz resonator in a region positioned inside of the length of the damping tube, characterized in that a fluid filter (35) is arranged inside of the damping housing (1) in the flow path running between the fluid inlet (13) and fluid outlet (15).

A muffler includes an exhaust pipe, a shell, and a cover. The exhaust pipe includes communication holes and is configured to allow an exhaust gas to flow through an interior of the exhaust pipe. The shell is disposed outside the communication holes to cover the communication holes. The cover has a tubular shape. The cover is disposed between the exhaust pipe and the shell. The cover is disposed at a distance, which is specified in advance, from the exhaust pipe.

The resonator is configured to attenuate the noise in a duct delimiting an internal channel for the flow of a fluid according to a reference axis, of the type including an annular compartment configured to extend around the channel and provided with at least one orifice forming a neck for communication with the flow channel so as to form a resonance chamber. Accordingly, the compartment has an inner structure with a geometry shaped so as to produce a revolution annular asymmetry of the resonance chamber about the reference axis, adapted to generate a phase shift of an acoustic pressure wave reflected inside the chamber relative to an acoustic pressure wave incident from the main flow.

A muffler including a double-pipe structure to muffle sounds in two or more frequencies is provided. The muffler includes an inner and outer pipes with a clearance therebetween. The inner pipe includes a first and second outer surfaces, and, at one end, an opening communicating with the outer pipe. The clearance communicates with an exhaust passage via the opening. The second outer surface forms the opening and is situated closer to the center of the inner pipe than the first outer surface is. A space between the inner and outer pipes is closed due to a contact between the first outer surface and an inner-circumferential surface of the outer pipe. A part of the clearance is formed between the first outer surface and the inner-circumferential surface. The outer-circumferential surfaces of the inner pipe include at least one communication hole that communicates the inner pipe with the clearance.

A muffler for an exhaust system of an internal combustion engine, especially for vehicles with hybrid drive, includes a muffler housing (12), a heat exchanger unit (48), arranged in the muffler housing (12), for transferring heat from combustion exhaust gas to a heat transfer medium, an inlet pipe (38), a first outlet pipe (52) and a second outlet pipe (40). A first exhaust gas flow path (54), in the muffler housing, routs exhaust gas through the heat exchanger unit (48) to the first outlet pipe (52). A second exhaust gas flow path (56), in the muffler housing, routs exhaust gas to a second outlet pipe (40), bypassing the heat exchanger unit (48). A flow path blocking/releasing device (58) for blocking and releasing at least one exhaust gas flow path (54, 56), of the first exhaust gas flow path (54) and of the second exhaust gas flow path (56).

A selectively tunable exhaust noise attenuation device includes a body having an outer surface and an inner surface that defines an exhaust volume. An inlet is coupled to the body and fluidically connected to the exhaust volume. A first outlet is coupled to the body and fluidically connected to the inlet and selectively fluidically connected to the exhaust volume and a second outlet coupled to the body and fluidically connected to the exhaust volume. A first conduit including a primary exhaust gas flow path directly fluidically connects the inlet and the first outlet. A second conduit includes a first end and a second. The second conduit defines a secondary exhaust gas flow path. A valve is fluidically connected to one of the first and second conduits. The valve is arranged laterally off-set of the primary exhaust gas flow path.

A vehicle exhaust system includes a tubular component having an inner surface and an outer surface such that the inner surface defines a primary exhaust gas flow path and wherein the tubular component extends along a central axis from an inlet end to an outlet end. The tubular component comprises at least one ridge along the central axis. The at least one ridge extends at least partly along a circumference of the tubular component. Each ridge includes a first portion angularly devoid of apertures and extending inwardly from the tubular component and a second portion disposed downstream of the first portion. The second portion is angularly devoid of apertures and extends inwardly from the tubular component. The tubular component also includes a plurality of spaced apertures positioned along a portion of the circumference of the tubular component and downsteam of the second portion.

Provided acoustic devices include an external housing defining an expansion chamber and a wall extending through and partitioning the expansion chamber into a central chamber and a peripheral chamber adjacent the central chamber, wherein an inlet and outlet communicate with the central chamber, and wherein the wall includes a plurality of apertures formed therethrough to allow air movement to and from the central and expansion chambers, the plurality of apertures sized to provide an average flow resistance ranging from 100 MKS Rayls to 5000 MKS Rayls. The acoustic devices advantageously show significant sound attenuation while streamlining air flow to reduce pressure drop across the expansion chamber.