An air-intake device comprises a vehicle body frame including a head box; and a pair of right and left main frames, wherein the head box includes: a casing section which extends between a front opening and a rear opening of the head box and is formed with a main air passage; and a pair of right and left extending sections coupled to the pair of main frames, respectively, wherein at least one extending section is provided with a branch air passage which branches from the main air passage, and wherein a separating wall is provided between the main air passage and the branch air passage and has a communication hole, and wherein when a vehicle body is viewed from a side, at least one extending section is extended rearward to a location at which at least a front region of the communication hole is covered by the extending section.

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 engine intake structure comprises an intake passage member 18 which defines an intake passage 36 for supplying air to an internal combustion engine 12, and which also defines a resonator chamber 40 in communication with the intake passage 36; and an in-vehicle device 14 located in an engine room 10 of a vehicle and having a preset reference temperature for temperature control, the intake passage member 18 being located above and adjacent to the in-vehicle device 14. The intake passage 36 extends above the in-vehicle device 14 so as to at least partially overlap the resonator chamber 40 as viewed in a vertical direction, thereby forming a two-layer structure, which makes the in-vehicle device 14 less affected by ambient temperature in the upper part of the engine room 10.

An apparatus for reducing flow noise of an air intake system of a vehicle is provided as an assembly of a body member and a cover member. An acoustic metamaterial unit includes a chamber having a predetermined size, an inlet flow path, and an outlet flow path provided therein and is connected to a pipe of an air intake system. The apparatus advantageously reduces or removes high-frequency flow noise occurring in a turbocharger by using the acoustic metamaterial unit. The size and shape of the acoustic metamaterial unit is standardized such that the acoustic metamaterial unit is used compatibly regardless of the type of vehicles, which can make it possible to advantageously reduce costs and improve salability.

A space-saving broadband resonator configured to install within and utilize inner space of other components and includes a resonator insert having a tubular pipe elongated along a central axis, the tubular pipe having a circumferential outer wall having a plurality of perforation holes spaced apart and extending radially through the circumferential outer wall. An interior of the tubular pipe forms a gas flow duct. A plurality of annular disk-shaped walls provided on and projecting radially outwardly from the tubular pipe. Adjacent annular disk-shaped walls spaced axially part from each other define resonator chambers therebetween. A bell mouth is formed at the second axial end of the tubular pipe, the bell mouth flared radially outwardly.

An intake system of a vehicle is configured so that air moves along a ‘U’-shaped movement path from an entrance of an intake duct portion into which outside air is introduced to a position where a filter is mounted, and is configured so that the intake duct portion, an air cleaner body portion, and an external resonator are formed integrally with each other.

An air induction system includes an air duct and an air permeable membrane. The air duct is configured to deliver intake air to an engine. The air duct includes a cylindrical wall defining a bore and an enclosure projecting from an outer radial surface of the cylindrical wall and defining a cavity therein. The cylindrical wall has an opening extending therethrough that enables airflow from the bore to the cavity in the enclosure. The air permeable membrane is configured to cover the opening in the cylindrical wall.

A vehicle shown herein is a side by side utility vehicle having frame configured to effectively transfer various loads throughout the frame as whole. The vehicle may further or alternatively include a routing tray configured to retain various fluid lines of the vehicle, a transmission including a passive duct acoustical attenuation device, a door seal configured to allow the frame to contact the seal at an angle, a modular door actuating mechanism, and/or a modular skid plate.

Disclosed herein is a meta-muffler for reducing broadband noise. The meta-muffler includes: a flow pipe through which a fluid flows; an outer barrel disposed outside the flow pipe to be spaced apart from the flow pipe; and multiple metastructures arranged in a flow direction of the fluid and each comprising an opening opened parallel to the flow direction of the fluid, a resonance chamber disposed between the flow pipe and the outer barrel and communicating with the flow pipe through the opening, and a neck adjustment member extending from the outer barrel toward the flow pipe to be spaced apart from the opening in the flow direction of the fluid. The meta-muffler can increase transmission loss of noise flowing through the flow pipe through maximization of energy loss of sound waves entering the resonance chamber of the metastructure and can effectively attenuate noise over a wide band ranging from low frequencies to high frequencies.

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.