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.

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 sound suppression assembly is provided for absorbing acoustic energy from an air circulation device. The assembly includes an air circulation device, such as an axial fan, and a plurality of sparsely-arranged two-sided Helmholtz unit cells disposed in a periodic array. Each unit cell includes a lossy resonator and a lossless resonator. The lossy resonator includes a first chamber portion bounded by at least one first boundary wall defining a first chamber volume, and a first neck forming an opening in the first chamber portion. The lossless resonator includes a second chamber portion bounded by at least one second boundary wall defining a second chamber volume, and a second neck forming an opening in the second chamber portion. The unit cells can be positioned in a circular pattern with the first neck of the lossy resonators directed to a source of acoustic energy from the air circulation device.

An exhaust system for an internal combustion engine of a motor vehicle includes a single exhaust-gas inlet line, two exhaust-gas outlet lines connected in an exhaust gas-conducting manner to the exhaust-gas inlet line, and an active silencing device. The active silencing device is connected in a sound-conducting manner to the two exhaust-gas outlet lines. Furthermore, a motor vehicle with such an exhaust system is provided.

An exhaust system for an internal combustion engine of a motor vehicle includes a single exhaust-gas inlet line, two exhaust-gas outlet lines connected in an exhaust gas-conducting manner to the exhaust-gas inlet line, and an active silencing device. The active silencing device is connected in a sound-conducting manner to the two exhaust-gas outlet lines. Furthermore, a motor vehicle with such an exhaust system is provided.

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.

An exhaust device (108) for a vehicle is provided. The exhaust device (108) includes an outer shell (202), an inlet (206) to receive exhaust gases, an outlet (208), an inner shell (204) received within the outer shell (202), a pair of partition walls (216) and a Helmholtz neck (220). The inner shell (204) defines an inner volume (210). A plurality of first circumferential openings (212) extending through the inner shell (204) fluidly communicates the inlet (206) with the inner volume (210). A plurality of second circumferential openings (214) extending through the inner shell (204) fluidly communicates the outlet (208) with the inner volume (210). The pair of partition walls (216) is disposed between the inner shell (204) and the outer shell (202). The pair of partition walls (216), the inner shell (204) and the outer shell (202) define a Helmholtz chamber (218) therebetween. The partition walls (216) seal the Helmholtz chamber (218) from the inlet (206) and the outlet (208). The Helmholtz neck (220) is disposed on the inner shell (204) or one of the pair of partition walls (216).

An exhaust device (108) for a vehicle is provided. The exhaust device (108) includes an outer shell (202), an inlet (206) to receive exhaust gases, an outlet (208), an inner shell (204) received within the outer shell (202), a pair of partition walls (216) and a Helmholtz neck (220). The inner shell (204) defines an inner volume (210). A plurality of first circumferential openings (212) extending through the inner shell (204) fluidly communicates the inlet (206) with the inner volume (210). A plurality of second circumferential openings (214) extending through the inner shell (204) fluidly communicates the outlet (208) with the inner volume (210). The pair of partition walls (216) is disposed between the inner shell (204) and the outer shell (202). The pair of partition walls (216), the inner shell (204) and the outer shell (202) define a Helmholtz chamber (218) therebetween. The partition walls (216) seal the Helmholtz chamber (218) from the inlet (206) and the outlet (208). The Helmholtz neck (220) is disposed on the inner shell (204) or one of the pair of partition walls (216).

A vacuum clear and an electric motor module (100) therefor are provided. The electric motor module (100) includes an outer casing (1) provided with an air inlet (10) at a front side thereof and an air outlet (11) at a rear side thereof; an electric motor assembly (2) arranged in the outer casing (1), and cooperating with the outer casing (1) to define an air passage in communication with the air inlet (10) and the air outlet (11); and a silencer (3) arranged at the air inlet (10), defining at least one resonant cavity therein, and the at least one resonant cavity having a side wall provided with a throat in communication with the resonant cavity.