An exhaust heat recovery system may include a muffler including a muffler case, a pipe through which exhaust gas flows, a baffle partitioning an internal space of the muffler case into a first space and a second space, and a valve mounted on an end portion of the pipe to change a direction in which the exhaust gas flows, and a heat exchanger mounted outside the muffler to fluidically-communicate with both the first and second spaces, allowing the exhaust gas to be introduced thereinto and to be discharged therefrom, the heat exchanger including a cooling channel through which cooling water flows, and heat exchange between the exhaust gas and the cooling water being performed in the heat exchanger.

A silencing apparatus is provided with a shell, ventilation pipes communicating with the inside of the shell, insertion holes which are respectively formed in the shell so as to have sizes smaller than surrounding skirt parts and allow the ventilation pipes to be loosely inserted in, and partitions partitioning the inside of the shell. In the silencing apparatus, at least, a sound-absorbing chamber partitioned by the partition and positioned adjacent to the insertion hole is filled with a sound-absorbing fiber material, and a sound-absorbing fiber material filling gap between the insertion hole and the ventilation pipe is closed by an annular closing member. To provide a silencing apparatus allowing a sound-absorbing chamber to be filled with sound-absorbing fiber material without a gap, even in a complicated configuration having the inside of a shell partitioned by a partition.

A silencing apparatus is provided with a shell, ventilation pipes communicating with the inside of the shell, insertion holes which are respectively formed in the shell so as to have sizes smaller than surrounding skirt parts and allow the ventilation pipes to be loosely inserted in, and partitions partitioning the inside of the shell. In the silencing apparatus, at least, a sound-absorbing chamber partitioned by the partition and positioned adjacent to the insertion hole is filled with a sound-absorbing fiber material, and a sound-absorbing fiber material filling gap between the insertion hole and the ventilation pipe is closed by an annular closing member. To provide a silencing apparatus allowing a sound-absorbing chamber to be filled with sound-absorbing fiber material without a gap, even in a complicated configuration having the inside of a shell partitioned by a partition.

A device for reducing airborne and structure-borne sound has a flow channel with a flow channel wall (22, 22, 22) and at least one resonator chamber (40, 40, 40) adjacent the flow channel wall (22, 22, 22). The flow channel wall is formed by a sound absorber (30, 30, 30) at least in a part bordering the resonator chamber (40, 40, 40). The sound absorber (30, 30, 30) is covered towards the resonator chamber (40, 40, 40) by an acoustically reflecting inner wall (42, 42, 42) of the resonator chamber with at least one wall aperture (44, 44, 44). Openings (32, 32, 32) completely covers the wall aperture (44, 44, 44) of the inner wall (42, 42, 42) of the resonator chamber such that sound waves flowing through the flow channel must pass the sound absorber (30, 30, 30) to enter the resonator chamber (40, 40, 40).

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.

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.

A muffler structure contains: a body, a first cover unit, and a second cover unit. The body includes an accommodation tube, fiber cotton, and a first mesh portion. The accommodation tube has an accommodating space and an internal fence. The first cover unit includes a manifold connection portion, a first polygonal cap, a hollowly tubular mesh having multiple orifices, a second mesh portion, and a stainless steel mesh. The second cover unit is fixed on a rear end of the accommodation tube of the body opposite to the first cover unit, and the second cover unit includes a second polygonal cap and a silencer. The second polygonal cap is covered on the accommodation tube of the body, and the second polygonal cap has a receiving portion defined in a free end thereof and configured to accommodate the silencer.

Method and system for filling a muffler with fibrous material. The muffler includes a muffler shell comprising a first shell member and a second shell member, at least one partition extending between the first and second shell members, and at least one slot formed in the first shell member above the partition. The first shell member is positioned and held relative to the second shell member to form an open portion, a closed portion, and a space between an upper surface of the partition and the first shell member. Fluid is introduced into the space through a fluid delivery device inserted into the muffler shell through the slot, and fibrous material is introduced into the muffler shell through a filling nozzle inserted into the muffler shell through the open portion. The fluid delivery device and nozzle are removed after filling and the shell members are closed and affixed.

Arrangements related to carbon flocked tape are described. The flocked tape can include a first adhesive, a substrate, a second adhesive, and a plurality of fibers. The substrate can be formed from any suitable metal, polymer, and/or natural material. The fibers can be formed from milled recycled carbon fibers. The carbon fibers can be connected within the tape via an electrostatic flocking process. The flocked tape can allow for application, removal, and re-application. The carbon flocked tape can provide several benefits, such as electric and/or thermal conductivity, noise and vibration reduction, insulation and shielding, and altered fluid dynamics.

Arrangements related to carbon flocked tape are described. The flocked tape can include a first adhesive, a substrate, a second adhesive, and a plurality of fibers. The substrate can be formed from any suitable metal, polymer, and/or natural material. The fibers can be formed from milled recycled carbon fibers. The carbon fibers can be connected within the tape via an electrostatic flocking process. The flocked tape can allow for application, removal, and re-application. The carbon flocked tape can provide several benefits, such as electric and/or thermal conductivity, noise and vibration reduction, insulation and shielding, and altered fluid dynamics.