An intake manifold is for a marine engine having a throttle for controlling flow of intake air to the marine engine. The intake manifold has a plenum for receiving the intake air from the throttle, a plurality of intake runners which extends from upstream ends for receiving the intake air from the plenum to downstream ends for discharging the intake air to the marine engine, and a quarter wave resonator extending from an open end coupled to the plenum to a closed end, the quarter wave resonator having a tuned elongated cavity configured to attenuate sound emanating from the marine engine via the plurality of intake runners.

Methods and systems are presented for diagnosing a breach of an evaporative emissions system. The methods and systems include repurposing a resonator as a vacuum reservoir to reduce a pressure of an evaporative emissions system so that it may be determined if there is or is not a breach of the evaporative emissions system.

An acoustic component is provided with a flow channel for a fluid. The flow channel has an inlet pipe and an outlet pipe. A flow channel section is arranged between the inlet pipe and the outlet pipe, wherein the flow channel section has a silencer volume connected in the flow channel section via openings to the flow channel. A flow deflection device is arranged at least in the flow channel section with the silencer volume, wherein the flow deflection device deflects a flow of the fluid in the flow channel section with the silencer volume away from the openings. The openings in the flow channel section are arranged in a sheltered zone of the flow deflection device.

A bracket 10 has a U-shaped cross section in which a pair of facing plate portions 15 extend from both side edges of a bottom plate portion 12 so as to face each other, and is fixed to a vehicle body side for mounting a predetermined component. The bottom plate portion 12 and the pair of facing plate portions 15 partition a bracket inner space 16, and the bottom plate portion 12 is provided with a through hole 20 which makes the bracket inner space 16 communicate with an outside. A resonator 23 is fixed to the bracket 10 in a state where the resonator 23 is accommodated in the bracket inner space 16. A ventilation passage 29 makes the resonator 23 communicate with the intake duct 21 through the through hole 20.

An apparatus of amplifying sound waves may include a metamaterial structure having a metamaterial inside thereof, an inlet through which air flows into the metamaterial structure, and a penetration portion formed to penetrate a portion of one side of the metamaterial structure, a membrane member coupled to the penetration portion, and a resonance member surrounding the membrane member and coupled to the metamaterial structure and including a space inside thereof and a discharge port fluidically communicating with an outside thereof and the internal space.

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.

An intake sound amplifier amplifies intake sound that is transmitted from an engine mounted in an engine compartment of a vehicle to a cabin. The intake sound amplifier includes a first passage branched from an intake passage, through which intake air is introduced into an engine; a device body that includes a vibrating body vibrated by pulsation of the intake air and is connected to a downstream end of the first passage; and a second passage that is connected to a downstream end of the device body and extends to the cabin side. The device body is located outward in a vehicle width direction of a side frame that extends in a vehicle front-rear direction and separates inside of the engine compartment from outside in the vehicle width direction.

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.

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.

In a structure for mounting resonators to a duct, the duct including openings is provided with a plurality of duct-side mounting pieces, and the resonators formed separately from the duct and including communication ports coupled to the openings are provided with a plurality of resonator-side mounting pieces that are mounted to the duct-side mounting pieces. Coupling portions of the duct and the resonators are configured to ensure turning the resonators when the resonators are mounted to the duct. On the plurality of duct-side mounting pieces disposed with intervals in a peripheral direction of the coupling portions, mounting surfaces are formed to be opposed to turning directions of the resonators when mounting the resonators to the duct, the resonator-side mounting pieces being abutted against and mounted to the mounting surfaces. Accordingly, it is possible to turn the resonators when mounting them to the duct and improve attachment work.