Abstract: An air duct of an internal combustion engine has an inner pipe providing a flow channel and a housing with a first housing part and a second housing part, wherein the inner pipe is arranged in the housing. The first housing part and the second housing part enclose a chamber between the inner pipe and the housing. The inner pipe has at least one section with perforations in a wall of the inner pipe, wherein the perforations completely penetrate the wall of the inner pipe. A cylindrical acoustic component at least partially encloses the at least one section of the inner pipe at an outer side of the inner pipe. A wall of the cylindrical acoustic component is provided, at least in sections thereof, with continuous openings. The flow channel is acoustically connected via the perforations and via the continuous openings to the chamber.

Abstract: There is provided a muffler structure of a saddle-type vehicle. The muffler structure is disposed at a downstream side of an exhaust pipe extending from an exhaust port of a cylinder head. A pipe is connected to the exhaust pipe and inserted into a muffler main body. The muffler main body includes a cylindrical portion and a reduced diameter portion joined to a downstream side end portion of the cylindrical portion and having a diameter reduced toward the downstream side thereof. The pipe includes a center pipe passing through the cylindrical portion, and a tail pipe disposed in the reduced diameter portion. An expansion chamber is formed by a space in the reduced diameter portion in the vicinity of the tail pipe.

Abstract: A muffler for an exhaust system of an internal combustion engine includes a housing, a through pipe that conducts exhaust gas during operation of the muffler and is guided through the housing, and a branch pipe fluidically branching off from the through pipe within the housing. The branch pipe has an upstream end at the through pipe and ends freely and open at an end face with a downstream end within the housing. The branch pipe has a length from the upstream to the downstream end or up to a lateral recess which has a cross-sectional area which is greater than half a pipe cross-section of the branch pipe. The branch pipe has downstream perforations in a section from ? of the length as measured from the upstream end A total area of the downstream perforations is smaller than half the pipe cross-section of the branch pipe, and no perforations or upstream perforations have a total area of at most 10% of the pipe cross-section of the branch pipe being present in a section before ? of the length.

Abstract: A damping device, in particular for damping or avoiding pressure surges, such as pulses, in hydraulic supply circuits, preferably in the form of a silencer, has a damping housing surrounding a damping chamber and having a fluid inlet (3) and a fluid outlet (5). A fluid receiving chamber (7) extends between the fluid inlet and the fluid outlet. A fluid flow crosses the damping chamber in a throughflow direction (11) from the fluid inlet (3) to the fluid outlet (5). Parts of the fluid receiving chamber (7) extend transversely with respect to the throughflow direction (11). The fluid receiving chamber (7) immediately adjoins the fluid inlet (3) and the fluid outlet (5). A guide element (51) is provided in the damping chamber. The fluid flow flows against the guide element changing the flow speed of the flow at least in sections.

Abstract: A mass airflow sensor according to the present disclosure includes a housing, a sensor element, and a flow deflector. The housing defines an airflow passage configured to receive air flowing in a first direction. The sensor element is disposed in the airflow passage and generates a signal indicating a mass flow rate of air flowing through the airflow passage. The flow deflector is disposed in the airflow passage downstream of the sensor element, extends from an inner wall surface of the airflow passage, and is configured to inhibit air flow through the airflow passage in a second direction that is opposite of the first direction.

Abstract: A heating, ventilation, and/or air conditioning (HVAC) system has a fan component defining a radially interior space and a radially exterior space and a tube disposed in the radially exterior space, the tube being in fluid communication with the radially interior space at a first angular location and a second angular location different from the first angular location.

Abstract: An aircraft such as a gyroplane has a thrust propeller, a tail unit, a fuselage, and a keel tube that links the tail unit to the fuselage. The keel tube has a structure that reduces sound. The sound-reducing structure has a flow line-shape, is arranged at least partly below the thrust propeller, and extends from the keel tube in directions normal a vertical longitudinal plane of the gyroplane. The sound-reducing structure may extend asymmetrically from the keel tube and may be located along the longitudinal axis of the gyroplane on the keel tube within an angle between 10 degrees forward and 30 degrees rearward a vertical line extending to the keel tube from the intersection of the thrust propeller rotational axis and the thrust propeller rotational plane. The sound-reducing structure may also contain a sound-absorbent material or may comprise a hollow body with several openings.

Abstract: A sealed compressor of the present invention comprises an electric component (110); a compression component (112); a sealed container (102) which accommodates the electric component (110) and the compression component (112) and stores lubricating oil (104) therein; and a suction pipe (170) which is provided to penetrate a wall portion of the sealed container (102), and through which a refrigerant gas suctioned into the sealed container (102) flows; wherein the compression component (112) includes a compression chamber (142) formed within a cylinder (134) and a suction muffler (146) through which the refrigerant gas flows; wherein the suction muffler (146) includes a muffling space (150), an exit pipe (154), an inlet pipe (152), whose suction port (151) opens in a substantially horizontal direction in the interior of the sealed container (102), a funnel-shaped refrigerant receiver section (160) provided to surround the suction port (151); and wherein the suction port (151) is placed such that its center (151A)

Abstract: Exhaust apparatus for four cycle (including Wankel) internal combustion engines is disclosed. The apparatus is configured to manage pressure waves created by expanding gas emitted from the engine combustion chambers, the net result being to enhance engine performance and attenuate noise over a wide range of engine RPMs.

Abstract: Systems and methods for acoustic feedback or resonance mitigation are provided. The systems and methods include an exhaust acoustic noise reduction apparatus having an exhaust port comprising an exhaust aperture, a first vane extending at least partially across the exhaust aperture, and a second vane extending at least partially across the exhaust aperture and intersecting the first vane, such that the first and second vanes are oriented to interfere with formation of an acoustic feedback loop and reduce an acoustic noise signature of the exhaust port.

Abstract: An exhaust gas carrying of an exhaust gas system of a combustion engine fulfills a sound-absorbing function and has an outer shell that comprises at least one sound-absorbing portion. The sound-absorbing portion is provided with micro perforations which have a sound-absorbing effect and through which exhaust gas is directly discharged to an external environment.

Abstract: A pass-through element for a motor vehicle front of dash panel system includes a body portion having an outer edge that surrounds a central web. A conductor pass-through member is provided in the central web, and a sound enhancing element provided in the central web alongside the conductor pass-through member. The sound enhancing element is configured and disposed to condition and conduct motor vehicle engine sound from an engine compartment to a passenger compartment through the motor vehicle front of dash system.

Abstract: An exhaust system for an internal combustion engine having a first exhaust tract assigned to a first group of cylinders of the internal combustion engine, and a second exhaust tract assigned to a second group of cylinders of the internal combustion engine, the first exhaust tract and the second exhaust tract being coupled to one another by a connecting line. A common bypass line branches off from the connecting line coupling the exhaust tracts.

Abstract: A fluid pathway is provided with a flow controller in at least a portion of its length wherein the flow controller comprises an active surface capable of influencing the fluid flow through the fluid pathway, the configuration of the active surface conforming to at least one logarithmic curve conforming to the Golden Section.

Abstract: An acoustic structure, including a pipe having a plurality of cavities that are partitioned by a partition, each of the plurality of cavities extending in a first direction that is a longitudinal direction of the pipe, wherein the pipe has at least one opening which permits the plurality of cavities to communicate with an exterior of the pipe, a position of each of the at least one opening in the first direction being a first position.

Abstract: An exhaust system for a vehicle features a pipe finisher including an inner sleeve. The inner sleeve has a reduced diameter portion spaced upstream from a downstream end of the inner sleeve. An exhaust pipe disposed in the inner sleeve, the exhaust pipe including a radially outward extending projection downstream of the reduced diameter portion of the inner sleeve.

Abstract: An air duct assembly supplies air from an air cleaner housing to an engine throttle and includes a first duct connected to the air cleaner housing and a second duct connected to the engine air intake. Open ends of the first and second ducts are spaced from one another and the second duct has a flared bell mouth at its open end. The second duct includes a sleeve that defines an attenuation chamber. A flexible bellows overlies the first and second ducts and the sleeve, and extends across the space between the first and second ducts to provide an airtight connection therebetween and flex during relative motion between the air cleaner housing and the engine air intake. A hydrocarbon adsorbing material can be housed within the attenuation chamber.

Abstract: The present invention aims to provide a muffling structure of a vent pipe and a muffling structure of a case, which is capable of muffling in a wide frequency range and preventing vent resistance in the air pipe or the case from deterioration. Vent holes (11a) are formed in the peripheral wall of the vent pipe (11), a cover (12) is so provided on the peripheral wall of the vent pipe (11) as to cover the vent holes (!1a), and a bag-like body (13) in which activated charcoal (14) is contained is disposed in the space formed by the peripheral wall of the vent pipe (11) and the inner wall of the cover (12).

Abstract: An absorptive muffler assembly includes a first body and a second body surrounding the first body. A resilient mount having at least one resilient portion and at least one support arm supports the first body and isolates the second body from vibrations of the first body.

Abstract: A silencer for a motorcycle has a front cup which has a tapered tubular shape, a center sleeve which is connected to the front cup, and a tail cup which is connected to the center sleeve. Since the front cup has a tapered tubular shape, the front cup is arranged such that a front end of the front cup is positioned in the vicinity of a main frame. A distal end of the silencer can be shifted frontward in the longitudinal direction of a vehicle compared to a silencer of a prior art. As a result, a length of the silencer can be increased while avoiding interference between the silencer and legs of a rider and hence, silencing performance of the silencer can be enhanced. Since the distal end of the silencer can be shifted frontward in the longitudinal direction of the vehicle, the concentration of a mass can be acquired.

Abstract: A vehicle muffler, which is structured in a coiled fashion, has a tube extending through the circumferential wall. This tube is welded to the circumferential wall and fastened by mechanical deformation to a support wall of an inner insert piece.

Abstract: A vehicular muffler is configured and arranged to smoothly introduce exhaust gas into a sound-absorbing material disposed inside of an outer case which has a plurality of relatively short inner sleeves therein. The muffler includes a porous plate which is disposed inside of the outer case, and which is connected to an exhaust pipe, and the porous plate is operatively connected to an outlet pipe which discharges an exhaust gas to the outside environment through an opening formed in an outlet side of the outer case. In one embodiment, the inner sleeves are arranged substantially parallel to each other, and are fluidly connected to a joint exhaust feed pipe disposed inside the outer case. The inner sleeves are connected to the outlet pipe on the outlet side of the outer case.

Abstract: A fairing is configured for use with the exhaust stack of a heavy-duty vehicle. The exhaust stack has an exhaust pipe with an intake end for receiving exhaust gases from an internal combustion engine and a discharge end for discharging the exhaust gases. The fairing includes a streamlined exterior surface and a cavity for receiving the discharge end of the exhaust pipe. An aperture extends through a rear portion of the exterior surface so that exhaust gases discharged from the discharge end of the exhaust pipe pass through the cavity and out of the aperture. The fairing further includes a coupler to couple the fairing to the exhaust pipe.

Abstract: A system for reducing an acoustic load of a fluid flow includes a first pipe. The first pipe includes a first end and a second end and a first aperture and a second aperture, the first and second apertures being intermediate the first and second ends. A second pipe includes a first end and a second end and a third aperture intermediate the first and second ends. The second pipe is connected at its first end to the first pipe at the first aperture. A bypass pipe includes a first end connected to the second aperture of the first pipe and a second end connected to the third aperture of the second pipe. A method of reducing an acoustic load of a flow in a standpipe connected to a first pipe configured to carry a main flow includes providing a bypass flow from the first pipe to the standpipe.

Abstract: An apparatus comprising includes a conduit portion having a conduit inner surface and a conduit outer surface, and a plurality of chambers in fluid communication with the conduit portion. The chambers include a first chamber defined, at least in part, by a first outer housing and a first chamber volume. The first chamber is in fluid communication with the conduit portion. A fluid is permitted to flow between the conduit portion and the first chamber through a first flow area. The chambers also include a second chamber defined, at least in part, by a second outer housing and a second chamber volume. The second chamber is in fluid communication with the conduit portion. A fluid is permitted to flow between the conduit portion and the second chamber through a second flow area. The first chamber volume is generally equal to the second chamber volume and the first flow area is greater than the second flow area.

Abstract: A muffler for an internal combustion engine exhaust system includes a housing having an inlet and outlet headers enclosing opposite ends of an outer shell. A partition divides a housing interior into first and second chambers, the first chamber having sound absorbing material positioned therein. The partition has an aperture allowing fluid communication between the first and second chambers. A through pipe extends through the inlet and outlet headers and the partition and has a plurality of perforations enabling fluid communication between the through pipe and the first chamber. A valve assembly has a valve flap positioned inside the through pipe for rotation with an axle pivotally coupled to the pipe between a closed position and an open position. The valve is positioned downstream of the pipe perforations such that all of an exhaust gas flowing through the muffler passes through the valve regardless of the valve flap position.

Abstract: A venturi muffler is made of a plurality of metallic tubular stepped members which are stacked together and define at least one sound-reflective chamber which opens through an annular venturi passage into an axial flow passage of the venturi muffler thereby creating a partial vacuum in the annular chamber. The annular chambers include aligned openings through which exhaust gasses flow but are also reflected by walls of the sound-reflective chambers. Therefore, the exhaust sound or noise is dampened by the cancellation of sound waves 180 degrees out of phase with each other, the creation of a partial vacuum through which sound cannot propagate or propagates minimally, and by the heat removed by all of the metallic heat-conductive venturi-forming segments of the venturi muffler.

Abstract: One embodiment of the invention includes a product including a fuel-cell exhaust diffuser; an air funnel; and at least two exhaust tubes attached to the diffuser.

Abstract: The present invention aims to provide a muffling structure of a vent pipe and a muffling structure of a case, which is capable of muffling in a wide frequency range and preventing vent resistance in the air pipe or the case from deterioration.

Abstract: A resilient mount useful in a muffler assembly includes a support arm, a bracket arm and at least one resilient portion. In one example, the resilient portion comprises neoprene to provide a cushion between the support arm and the bracket arm. The resilient mount is for supporting at least one absorptive body within a housing and isolating the housing from vibrations of the absorptive body.

Abstract: The present invention is for a triangular cross section symmetrical engine exhaust muffler for an internal combustion engine. Its internal design provides baffles symmetrically disposed about a plane centrally located equidistant from the ends of a tube having a triangular cross section. The design has three baffles spaced to minimize backpressure but angled to enhance acoustic reflections within the chamber formed by the tube having a triangular cross section, baffles, and the affixed endplates including the inlet/exhaust ports. These acoustic reflections serve to modify the sound emanating from the exhaust manifold or manifolds of the internal combustion engine. The muffler chamber also serves to smooth out the pulsating gas flow emanating from the engine as a result of the combustion cycle.

Abstract: A refrigerant compressor has a hermetically tight compressor housing inside of which a piston-cylinder unit operates. A suction muffler through which refrigerant flows to the intake valve of the piston-cylinder unit is provided on the cylinder head. The inlet of the suction muffler has a cross section via which refrigerant flows into the suction muffler. A compensating volume is provided inside of which refrigerant oscillates and which is connected to the suction muffler and the interior of the compressor housing. The cross section of the inlet also acts as the connecting port between the compensating volume and the filling volume. The compensating volume is formed by an outer tube directed into the compressor housing, which tightly surrounds the intake port of the inlet while surrounding the section of the refrigerant suction pipe that is connected to the evaporator of the compressor and extends into the interior of the compressor housing.

Abstract: A passive, exhaust pressure actuated valve assembly for placement inside a tubular exhaust conduit is pivotally mounted to an off-center axle for rotation between fully closed and fully opened positions. A bias element forces the valve flap toward the fully closed position. The valve flap is shaped in a manner enabling use of the interior surface of the exhaust conduit to define stops at the full closed and full opened positions. The valve flap shape, in conjunction with the bias element arrangement, enables the flap to lie substantially parallel to a longitudinal axis of the conduit in the fully opened position, which provides for minimum back pressure in the conduit. The valve assembly finds particularly advantageous use inside a bypass through pipe of a muffler assembly.

Abstract: A muffler that inhibits reduction in engine performance and reduces exhaust noise volume includes a conduit that passes through an expansion chamber. A partition wall is provided at a central section of the conduit. An upstream section upstream from the partition wall includes an outflow section that has a side surface in which outflow holes are formed that allow exhaust gas to flow out to the expansion chamber. A downstream section downstream from the partition wall has an inflow section that has a side surface formed with inflow holes that allow exhaust gas to flow in from the expansion chamber. An inner diameter of at least one section of the downstream section is smaller than an inner diameter of the outflow section.

Abstract: An exhaust pipe for an internal combustion engine includes an inner tube carrying a flow of exhaust gas and surrounded by an outer tube, with an insulating layer disposed between the inner tube and the outer tube. The inner tube has at least one region formed with a nub-shaped profile in contact with the flow of exhaust gas.

Abstract: Mufflers having polymeric bodies that are protected from being overheated from the exhaust pipe by having an air gap between the exhaust pipe and the polymeric body are disclosed. Also disclosed is a process for making muffler systems wherein the muffler polymeric bodies have a cross section that is constant over the length of the muffler polymeric body. The muffler systems are inexpensive to make and install.

Abstract: A pulsation dampener for receiving a fluid medium containing pressure pulsations. The pulsation dampener can include a body having an inner surface, an inlet, and an outlet, and a fluid path defined at least partially by the inner surface of the body. The fluid path can include a first chamber in fluid communication with the inlet and having a first cross-sectional area, a second chamber positioned adjacent the first chamber and having a second cross-sectional area different from the first cross-sectional area, and a third chamber in fluid communication with the outlet and positioned adjacent the second chamber opposite the first chamber and having a third cross-sectional area different from the second cross-sectional area. The fluid path can be configured such that the second cross-sectional area is greater than the first cross-sectional area and the third cross-sectional area.

Abstract: A system for reducing an acoustic load of a fluid flow includes a first pipe. The first pipe includes a first end and a second end and a first aperture and a second aperture, the first and second apertures being intermediate the first and second ends. A second pipe includes a first end and a second end and a third aperture intermediate the first and second ends. The second pipe is connected at its first end to the first pipe at the first aperture. A bypass pipe includes a first end connected to the second aperture of the first pipe and a second end connected to the third aperture of the second pipe. A method of reducing an acoustic load of a flow in a standpipe connected to a first pipe configured to carry a main flow includes providing a bypass flow from the first pipe to the standpipe.

Abstract: An apparatus for sonic coupling between an intake tract or engine compartment and a vehicle interior of a motor vehicle has a housing into which sound enters from the intake tract via a first line, and out of which sound exits into the vehicle interior via a second line. A transmission body is arranged in the housing, the transmission body having a gas-tight separating wall between a sound inlet into the housing and a sound outlet out of the housing. The position of the separating wall is held essentially constant by a positioning device. A transmission wall between the separating wall and the housing provides an acoutis transfer function that is adjustable. The separating wall runs generally perpendicular to the longitudinal axis of sound propagation and the transmission wall runs at an angle ? to the longitudinal axis of sound propagation.

Abstract: Described herein is a pipe/silencer device assembly comprising a connection element, which has a through hole, having an axis, and a branching off hole, which is fluidically connected to the through hole wherein the assembly comprises: first connection means adapted for co-operating with a first duct; a second duct, fluidically connected to the connection element; and a blind silencer duct, fluidically connected to the branching off hole.

Abstract: A silencer for attenuating a sound includes an inner duct in which gas flows, and an outer duct surrounding the inner duct with a gas layer formed between the outer duct and the inner duct. The sound is generated in one of an upstream side of the inner duct in a gas flow direction, a downstream side of the inner duct in the flow direction, and an inside of the inner duct. The inner duct includes a thin film over its entire surface. The film has a first reinforcement section formed in a direction parallel to the flow direction, and a plurality of vibrating surfaces. The film is bent at the first reinforcement section. Each combination of adjacent two of the plurality of vibrating surfaces is connected by the first reinforcement section. The first reinforcement section of the inner duct is fixed to the outer duct.

Abstract: An engine air intake system, which may include a supercharger or other air-handling device, includes a resilient coupling connecting an air intake connector, such as a throttle body, and an air inlet duct. The resilient coupling includes a bellows convolution for allowing limited motion between connected components. The coupling is molded with tuning volumes and connecting passages within the convolution with open sides to allow removal from the mold die. An associated connector closes the chambers upon assembly and forms noise reduction tuning for high frequency air pressure waves.

Abstract: The present invention describes an automobile exhaust pipes, and more particularly to an exhaust pipe capable of producing appropriate pressure to assist engine torque output when the engine is running at a low speed and expediting the waste gas to be discharged from an automobile when the engine is running at a high speed, so as to enhance the operating performance of automobile engines.

Abstract: The shell main body for a muffler includes an inner shell in a cylindrical shape with a cross-section of an imperfect circle defined by small arc portions alternating with large arc portions; and an outer shell wrapping the inner shell and formed in a cylindrical shape similar to the inner shell. An end portion of the inner shell and an end portion of the outer shell are overlapped in a circumstantial direction of the shell main body to form a shell overlap portion that is capable of discharging vapor in a gap of the large arc portions formed between the inner shell and the outer shell into one of an outside and an inside of the shell main body. This shell overlapping portion is located in one of the small arc portions.

Abstract: A cylindrical shell main body constituting a muffler main body is formed of two layers of an inner shell and an outer shell and has a cylindrical shape with a cross section that is not a perfect circle but is defined by alternated small arc portions and large arc portions similarly to an oval, or the like. The outer shell of the shell main body has, in each of their small arc portions, four radially projecting beads continuously extending in a circumferential direction along the small arc portions and being a predetermined distance apart from one another in an axial direction, thereby allowing an upper and lower gaps between the inner shell and the outer shell in the respective large arc portions of the shell main body to communicate with each other through passages formed by the beads.

Abstract: A fluid guideline with at least two structural elements made of substantially soundproof material has at least one opening for sound damping. An impedance change (in particular in the form of an impedance discontinuity) of the flow resistance of the fluid flowing through the fluid guideline is present between two adjacent structural elements, and the at least one opening is arranged in the region of the impedance change between two adjacent structural elements.

Abstract: An air induction system for inducting air into an engine of an automobile is disclosed. The air induction system has an air cleaner and an air inlet tube. The air cleaner is in fluid communication with the engine of the automobile for filtering intake air inducted into the engine. The air inlet tube is made of a first material and is connected at a first end to the air cleaner and open to ambient air at a second end. The inlet tube has a flexible portion that flexes as a result of internal pressure pulsations during the air induction event. The flexing reduces or eliminates acoustic standing waves that have significant pressure fluctuations at the same location in the air induction system as the flexible portion.

Abstract: A silencer for silencing and also for filtering exhaust gases, contains at least one acoustic resonator chamber (13, 14, 15, 16) (Helmholtz frequency), at least one porous body (7, 8) the porous body (7, 8) occupying at least part of the chamber and at least one connecting passage (17) for leading gas from each one of the acoustic chamber wherein the connecting passage (17) extend along the outher surface of the porous body, so as to lead along a helical flow path (19).

Abstract: The manufacturing method for the air intake apparatus has a holding-portion forming step, a temporarily fixing step, and a joining step. In the holding-portion forming step, a holding portion is formed. In the temporarily fixing step, the porous member is held by the holding portion. In the joining step, the holding portion and the porous member are joined together. Thus, an air intake apparatus, in which the opening is reliably covered with the porous member, can be manufactured. In the air intake apparatus manufactured by this manufacturing method, a peripheral portion of the porous member is doubly sealed with the holding portion that is an outer edge part of the opening. Consequently, the opening is reliably covered with the porous member, so that intake noise is reliably reduced.

Abstract: The present invention provides a noise attenuation assembly having at least one noise prevention pad disposed within an annular gap formed between a gas passage tube and an overlap tube. The noise prevention pad prevents the two tubes from coming in contact during thermal expansion of the tubes, and allows the tubes to contract without causing “tick and ping” noise, during a cool down.