A silencer having an outer housing; and a central perforated tube through which air flows. The silencer further includes an additional perforated structure located between the central perforated tube and the outer housing, a first chamber is formed between the central perforated tube and the additional perforated structure, and the additional perforated structure is configured such that at least one second chamber is formed, which is at least partially located radially outside of the first chamber, where the second chamber is communicated with the first chamber by perforates. The disclosure further relates to a vehicle engine having the silencer. The silencer is compact in structure, and has a better broadband silencing effect.

An engine cover covers an engine; and an intake pipe through which the air is introduced into the engine. An intake silencer is provided adjacent to the intake pipe and suppresses air pressure fluctuations of air in the intake pipe to reduce intake sound. A portion of the intake silencer is covered with the engine cover, and a remaining portion is exposed with respect to the engine cover. An advantage is that secondary noise generated by the intake silencer and a temperature increase of air suctioned into the engine are simultaneously suppressed.

The present invention relates to a vehicle silencer comprising: a first case provided in a vehicle; a second case coupled to the first case; a resonant chamber positioned between the first case and the second case; and a passing hole formed by penetrating the second case, such that the inside of the second case and the resonant chamber communicate with each other therethrough, wherein the second case includes a first passing member formed such that the thickness thereof gradually decreases toward a first direction.

A supercharger assembly comprises a housing, a rotor bore with an outer wall, an outlet in an outlet plane, an inlet in an inlet plane perpendicular to the outlet plane, and an outlet divider wall. The supercharger assembly comprises a first recess, a first perforated material covering the first recess, and an outlet resonator. The first recess is separated from the outlet by the outlet divider wall. The first recess is located between the outer wall and the first perforated material.

A straddled vehicle includes an air cleaner and a resonator. The air cleaner includes an air cleaner case, an air-cleaning element arranged inside the air cleaner case, and a duct that is attached to the air-cleaning element. At least a portion of the duct is arranged inside the air cleaner case, and the duct guides the air toward the air-cleaning element. The resonator has an outer wall arranged around the duct. The duct and the outer wall together define at least a portion of a resonance chamber of the resonator.

A resonator includes: an inner pipe having first openings penetrated into an outer peripheral surface thereof from an inner peripheral surface thereof and second openings spaced apart from the first opening; a first cover adapted to allow a first resonant space to be formed between the outer peripheral surface of the inner pipe and the inner peripheral surface thereof, the first resonant space communicating with the internal space of the inner pipe through the first openings; and a second cover adapted to allow a second resonant space to be formed between the outer peripheral surface of the inner pipe and the inner peripheral surface thereof, the second resonant space communicating with the internal space of the inner pipe through the second openings.

A device (1) for lowering flow noises has opposed first and second connection pieces (2, 3), and outer and inner sleeves (4, 5) between the connection pieces. A radial collar (6) is between the sleeves (4, 5) and forms separated volume chambers. Openings (11) in the inner sleeve (5) connect the volume chambers to a line space (13) enclosed by the inner sleeve (5). A sealing ring (15) at the free end (14) of the collar (6) defines a ring cap with a lateral surface (21) that reaches over the collar (6) and seals against the sleeve (4, 5) adjacent the free end (14) of the collar (6) and that has a surface (23, 26) that seals against either an end face (25) of the collar (6) or a side surface (28) of the collar (6) extending parallel to the radial collar (6).

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.

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.

A high frequency attenuating device for an air flow induction system of a vehicle employing a thermoformed fibrous mat of any shape that fits robustly inside the duct. The dissipative nature of the fibrous mat helps in achieving broadband attenuation in the high frequency regime. The ability to manufacture the fibrous mat into any shape helps with restriction, targets different attenuation bands, and makes it more feasible to manufacture. Hybrid solutions are possible when combined with low frequency perforated silencers or high frequency QWT arrays injection molded onto them.