A device for controlling an exhaust sound of a vehicle includes a sound tunnel mounted near a muffler and an exhaust pipe so as to transmit exhaust sound to an interior of a vehicle, a sound introduction hole formed in the sound tunnel, and a catalytic assembly mounted in the sound tunnel so as to clog the sound introduction hole, the catalytic assembly functioning to reduce high-frequency noise and to filter exhaust gas, thereby reducing high-frequency noise included in the exhaust sound transmitted to the interior of the vehicle and thereby filtering the exhaust gas so as to prevent introduction of the exhaust gas into the interior of the vehicle.

A device for controlling an exhaust sound of a vehicle includes a sound tunnel mounted near a muffler and an exhaust pipe so as to transmit exhaust sound to an interior of a vehicle, a sound introduction hole formed in the sound tunnel, and a catalytic assembly mounted in the sound tunnel so as to clog the sound introduction hole, the catalytic assembly functioning to reduce high-frequency noise and to filter exhaust gas, thereby reducing high-frequency noise included in the exhaust sound transmitted to the interior of the vehicle and thereby filtering the exhaust gas so as to prevent introduction of the exhaust gas into the interior of the vehicle.

An exhaust muffler has an outer cylinder into which an exhaust gas from an engine is introduced and a muffling member made of a foamed ceramic material. The outer cylinder has an inner cylinder through which the exhaust gas passes, a part of the muffling member is supported by an outer wall of the inner cylinder via a holding member. The inner cylinder includes, in an area where the inner cylinder overlaps with the muffling member with respect to axial direction of the inner cylinder, a porous wall portion formed with communication holes communicating an inside and an outside of the inner cylinder. The holding member is arranged at a position where it does not overlap with a part of the porous wall portion, so that muffling effect is enhanced, and the muffling member having a low resistance to impact forces can be supported stably by the inner cylinder.

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 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.

The present invention aims to provide a sound-absorbing material having sound absorption performance with an average sound absorption coefficient of 0.65 or more in the frequency domain of 800 to 2000 Hz. The present invention relates to a sound-absorbing material including: a fiber layer including a plurality of holes open to a surface thereof and having a thickness of 3 mm or more; and an inorganic material layer formed on the surface of the fiber layer, the holes being blind holes each penetrating through the inorganic material layer and having a bottom inside the fiber layer.

Disclosed herein is a method and an insert device for an internal combustion engine including: a central exhaust passage; a first expansion chamber in an upstream portion of the exhaust system and in fluidic communication with the central exhaust passage; a second expansion chamber in a downstream portion of the exhaust system and in fluidic communication with the central exhaust passage and the first expansion chamber, forming a continuous expansion chamber throughout a length of the insert device.

Disclosed herein is a method and an insert device for an internal combustion engine including: a central exhaust passage; a first expansion chamber in an upstream portion of the exhaust system and in fluidic communication with the central exhaust passage; a second expansion chamber in a downstream portion of the exhaust system and in fluidic communication with the central exhaust passage and the first expansion chamber, forming a continuous expansion chamber throughout a length of the insert device.

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 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).