Abstract: A noise attenuating device for reducing acoustic resonance in a cavity of an aircraft with an opening in a skin of the aircraft defining a first surface area and an opening peripheral edge includes a connection mechanism for securing the noise attenuating device in proximity to the opening in the skin of the aircraft and an exterior surface. The exterior surface defines a second surface area that is less than the first surface area of the opening and a device peripheral edge, which has a first section having an edge profile complimentary to at least a portion of the opening peripheral edge and a second section having an indented edge profile in relation to the first section such that when the noise attenuating device is secured within the opening, at least one gap is formed between the device peripheral edge and the opening peripheral edge.

Abstract: A compressor assembly having a high velocity muffler system which produces a particle-free compressor pump feed while reducing noise output from the compressor assembly during compressing operations. The high velocity muffler system is maintenance-free and comprises an inertia filter. The compressor assembly uses a method for producing a compressor pump feed and reducing noise during compressing operations by processing a gas through the high velocity muffler system which has an inertia filter and a muffler chamber to produce a compressor pump feed which can be compressed by a pump assembly.

Abstract: One aspect of the present disclosure provides a muffler including an exhaust pipe and a space forming member. The exhaust pipe has a cylindrical shape having a flow passage inside through which exhaust gas passes. The space forming member forms closed spaces between itself and the exhaust pipe, the closed spaces being branched from the flow passage and adjacent to the flow passage. Each of the closed spaces and the flow passage communicate with one another via a single communication hole.

Abstract: Disclosed are a silencer and a compressor with same. The silencer includes a housing, a gas inlet end of the housing being provided with a protrusion extending into an interior of the housing, a portion of the protrusion approximate to a gas outlet end of the housing being closed, and the gas inlet end of the housing being provided with at least two gas inlets around the protrusion. A part of a gas flow enters the housing through the gas inlets, and other part of the gas flow impacts the protrusion and then at least partially flows back and enters the housing through the gas inlets.

Abstract: A muffler, for an internal combustion engine exhaust system, includes a muffler housing (12) with a housing jacket (14) elongated in a housing longitudinal axis (A) direction and with an outer panel (16) connected to the housing jacket at both axial end areas thereof to define a muffler interior (18). An inner panel (20) is arranged in and divides the muffler interior. A muffling unit (24) includes an exhaust-gas-carrying inner pipe (26), an outer pipe (28) enclosing the inner pipe and muffling material (32) arranged between the inner pipe and the outer pipe. The inner pipe is accommodated in an opening (48) of an inner panel and in an opening (40) of one of the outer panels or of an additional inner panel. The outer pipe is permanently connected to the inner panel or/and to one of the outer panels or to the additional inner panel.

Abstract: A muffler for an exhaust system of an internal combustion engine includes a muffler housing (14) and at least one exhaust gas pipe group (19). The at least one exhaust gas pipe group (19) includes an outlet pipe (20) open towards an expansion chamber (26) formed in the muffler housing (14). Exhaust gas introduced via the at least one exhaust gas pipe group (19) leaves the muffler housing (16) via the outlet pipe (20). A first inlet pipe (38), of the at least one exhaust gas pipe group (19), has an inlet pipe end area (40), which is inserted into the outlet pipe (20) and extends in the outlet pipe (20). A second inlet pipe (48), of the at least one exhaust gas pipe group (19), is open towards the expansion chamber (26).

Abstract: Provided is a tail pipe in which a silencing effect at a discharge port is obtained. One aspect of the present disclosure is a tail pipe including: an inner tube including a discharge port configured such that an exhaust gas is discharged therefrom; an outer tube arranged so as to form a space between the outer tube and the inner tube by surrounding an outer peripheral surface of the inner tube, an upstream end of the outer tube in a flow direction of the exhaust gas being closed; and at least one communication hole allowing communication between an interior of the inner tube and the space.

Abstract: There is provided a method for filling a silencer with glass fiber, for filling an internal space between a case and an inner pipe with glass fiber in a silencer in which a porous inner pipe penetrates through a pair of through holes in the case, the method including shifting the inner pipe in a penetrating direction from a normal position where the inner pipe is secured to the case, inserting a nozzle auxiliary portion into an interior of the case from a through hole opened by the inner pipe being shifted, supplying glass fiber into the interior of the case from a nozzle of a glass fiber supply machine connected to the nozzle auxiliary portion, and filling the internal space between the case and the inner pipe with glass fiber.

Abstract: The invention relates to a fluid pipe arrangement (100), in particular for a charged air duct of an internal combustion engine, comprising a housing (10) having a longitudinal extension (L). The housing (10) includes a first fluid duct (20) having a first fluid inlet (22) and a first fluid outlet (24) for a first fluid and at least one second fluid duct (30) having a second fluid inlet (32) and a second fluid outlet (34) for a second fluid. Thermal insulation means (40) are provided between at least a portion (38) of the second fluid duct (30) and at least a portion (28) the first fluid duct (20).

Abstract: An apparatus for engine exhaust sound attenuation includes a housing, a plurality of baffle plates arranged within the housing. The baffle plates are disposed apart from each other to define a plurality of intermediate chambers. The plurality of intermediate chambers includes a first resonant chamber proximate to the outlet chamber, a second resonant chamber proximate to the inlet chamber, a first intermediate chamber proximate to the second resonant chamber, and a second intermediate chamber proximate to the first intermediate chamber and the first resonant chamber. An inlet tube and an outlet tube are included. A first tube directs a flow of exhaust from the inlet chamber to one of the plurality of intermediate chambers via an interior of the first tube. Additionally, a second tube directs the flow of exhaust from a second one of the plurality of intermediate chambers to the outlet chamber via an interior of the second tube.

Abstract: A sound suppression chamber for a heating, ventilation and air conditioning (HVAC) air handling assembly including a first end, a second end, and a middle portion. The first end includes an aperture that resonates with airflow from the HVAC air handling assembly, the airflow from the HVAC air handling assembly generating an incident sound wave corresponding to a target tone. The second end is closed and opposite the first end. The middle portion extends between the first end and the second end. The first end, the second end, and the middle portion defining a cavity of the sound suppression chamber. The sound suppression chamber generates a reflected wave that is 180 degrees out of phase from the incident sound wave and reflected into the HVAC air handling assembly through the aperture to suppress the target tone.

Abstract: A method of sub-ambient pressure processing of blow-molded polymer foams and skin-over-foam sandwich panel configurations for lightweight components having improved structural properties. The method can create either skinned or un-skinned foams that offer smooth interior and exterior surfaces, zero or controlled surface porosity, skins of pre-defined thickness, and foam cells that are expanded and oriented normal to the material plane, effectively spherical or polyhedral in nature, and offering improved bending and compressive strength.

Abstract: A pressure pulsation trap is provided. The pressure pulsation trap includes a channel extending from an inlet to an outlet, and a plurality of branches extending from the channel, each of the branches having different lengths than one another. The different lengths are configured such that the branches attenuate noise and/or vibration over a range of operating frequencies.

Abstract: An improved catalytic converter includes a Coanda chamber assembly connected upstream of a catalytic reaction chamber, where the exhaust pipe is to be connected to the Coanda chamber assembly. The Coanda chamber assembly forms a Coanda chamber that has at least one narrower section and at least one wider section immediately downstream of the narrower section, with openings formed at the narrowest point of a narrower section. In operation, when engine exhaust gas is fed into the Coanda chamber, the gas pressure increases at the narrower section, and drops when the gas enters the wider section. As a result, air is sucked into the Coanda chamber via the openings and mixes with the exhaust gas. This lowers the exhaust temperature and enhances the efficiency of the catalytic reactions in the catalytic reaction chamber.

Abstract: A sound suppression system for reducing or eliminating sound produced by the operation of a breast vacuum pump includes a sound suppressing muffler assembly having an air entry port adapted to communicate with an air outlet port of a vacuum pump or other air flow generating device. The sound suppressing muffler assembly also includes a muffler housing defining an internal space communicating with the air entry port, and an opening in the housing leading to atmosphere. The muffler housing has a tortuous air path in the muffler housing. In one embodiment, sound absorbing porous foam structure is disposed in the tortuous air path. The at least one sound absorbing porous structure absorbs sound energy from the air as the air moves through the at least one air path toward the opening in the muffler housing. In further embodiments, a tortuous air path is provided between an air entry port and an opening to atmosphere in the muffler assembly.

Abstract: The present application provides an acoustic nozzle for an inlet bleed heat system using a flow of compressor discharge air. The acoustic nozzle may include an outer casing, an acoustic attenuation medium within the outer casing, a number of exit apertures positioned in the outer casing, an air pipe in communication with the outer casing, and a reduced flow area positioned about the outer chamber and the air pipe for the flow of compressor discharge air.

Abstract: A vehicle charge air cooler of a vehicle engine air induction system. The vehicle engine air induction system could also be equipped with a turbocharger or a supercharger located upstream of the vehicle charge air cooler. The vehicle charge air cooler has an inlet housing. The inlet housing includes an inlet chamber and a resonator chamber. The inlet housing includes an inlet chamber and at least one resonator chamber. The inlet chamber is defined by an exterior wall of the inlet housing and at least one in interior wall disposed within the inlet housing. The resonator chamber includes an insulation material, an exterior wall region, and an interior wall wherein the insulation material is disposed between the interior and exterior walls. The interior wall defines at least one aperture and divides the resonator chamber from the inlet chamber. The insulating material is configured to attenuate sound waves.

Abstract: A rugged noise muffler system is configured to substantially surround sound-emitting openings in a working unit or structure, to absorb sound emitted from the sound-emitting openings. A barrier component, formed as a housing, covers a sound emitting opening to inhibit sound from emanating from the housing, except at an open end of the housing. Each sound emitting opening in the working unit or structure requires a housing positioned over same. The housing includes a hood portion and an elongate portion that includes the open end of the housing. The inner surfaces of the hood portion and an elongate portion are lined with sound absorbing material. The emitted sound first enters the hood portion, is partially absorbed therein and any unabsorbed sound passes into and is substantially absorbed in the elongate portion as the sound travels towards the open end of the housing.

Abstract: Projection row (2) and recess row (3) are alternately and successively formed in a direction (Y-direction) perpendicular to a direction (X-direction) of their rows, thereby forming a corrugated cross-sectional shape of a cross-sectional wave shape. Between projection row (2) and recess row (3), there is provided inclined wall surface (4) having a wave shape in plan view. Each of projection row (2) and recess row (3) has a shape in a cross-section along X-direction that is formed into a corrugated cross-sectional shape of a wave shape. Pitch and height difference between valley portion (5) and crest portion (6) in the corrugated cross-sectional shape along this X-direction are smaller, as compared with a relationship between projection row (2) and recess row (3) in the corrugated cross-sectional shape along Y-direction.

Abstract: An acoustic filter includes holes and is configured to receive sound waves generated by an audio driver of a playback device. The sound waves comprise sound waves of a first frequency that radiate according to a first radiation pattern and sound waves of a second frequency that radiate according to a second radiation pattern that is less directed along an axis of the audio driver than the first radiation pattern. The second frequency is lower than the first frequency. The acoustic filter is configured to attenuate the sound waves of the first frequency so that the attenuated sound waves of the first frequency are emitted from the acoustic filter according to an effective radiation pattern that is less directed along the axis of the audio driver than the first radiation pattern and pass the sound waves of the second frequency in substantial accordance with the second radiation pattern.

Abstract: An intake duct assembly for an auxiliary power unit system is provided. A first inlet adapter includes at least one hole through the duct wall. A fire containment apparatus forms a first passage to direct intake air between exterior wall of the aircraft and the enclosure. An inner duct mounted on the first inlet adapter at a first position downstream of the at least one hole and mounted on the second inlet adapter. An outer sheath is mounted on the first inlet adapter at a second position upstream of the at least one hole and mounted on the second inlet adapter. The outer sheath circumscribes the inner duct to form at least a portion of a barrier annulus between the inner duct and outer sheath in fluid communication with the first passage via the at least one hole in the first inlet adapter.

Abstract: Aircraft, air conditioning systems, and air diffusers that may be used to create a quiet, comfortable environment within an aircraft cabin are disclosed. The systems and apparatuses are configured to flow air at a rate that meets and/or exceeds the FAA minimum requirement of 0.55 lbs/min (about 250 g/min) per occupant. In use, even at higher flow rates, the systems and apparatuses are configured to create a quiet cabin experience, by contributing little to ambient cabin noise. Thus, the systems and apparatuses may be used to provide fresh air at a comfortable rate and a comfortable noise level.

Abstract: Aircraft, environmental control systems, and air diffusers that may be used to create a quiet, comfortable environment within an aircraft cabin are disclosed. The air diffusers include a duct, a grille, and a porous flow conditioner positioned at least partially within an outlet plenum of the duct. The porous flow conditioner is configured to create backpressure and to reduce a velocity of air flowing out of the porous flow conditioner, relative to air flow unaffected by the porous flow conditioner. The porous flow conditioner may be configured to reduce noise generated by air flow through the air diffuser assembly, relative to air flow unaffected by the porous flow conditioner. The porous flow conditioner may be configured to reduce noise generated by air flow downstream of the porous flow conditioner.

Abstract: A muffler for a positive displacement pneumatic motor includes a case, an inlet, a diffuser, a pathway, and sound absorbing material. The inlet and the diffuser are attached to the case. The pathway extends between the inlet and the diffuser and allows ice to travel through the muffler. The sound absorbing material is positioned in the pathway and includes more than one duct through which gas passes.

Abstract: A steam diffusing apparatus may include a steam inlet tube having steam-dispersion openings adjacent a lower end thereof and a mass of filaments surrounding the plurality of steam dispersion openings. The steam diffusing apparatus may also include a retaining tube surrounding the mass of filaments, a housing surrounding the retaining tube and having outlet openings therein, and an upper end cap coupled to an upper end of the housing and having an opening therein receiving the steam inlet tube. A lower end cap may be coupled to a lower end of the housing.

Abstract: A muffler for an exhaust system of an internal combustion engine comprises: a casing having an inner space, an inlet pipe for sound to enter the muffler, an outlet pipe for sound to exit the muffler, and a separation wall arranged to extend from the inlet pipe to the outlet pipe and being embodied in a manner such as to define first and second acoustical ducts extending through the casing to allow sound propagating along the first acoustical duct to enter the inner space of the casing and to thereafter exit the inner space of the casing again, and to allow sound propagating along the second acoustical duct to acoustically bypass the inner space of the casing.

Abstract: A cyclonic separator for a vacuum cleaner that includes a cyclone stage, a chamber and a silencer. The chamber has a plurality of ports through which fluid from the cyclone stage enters the chamber. The silencer is located in the chamber and includes a plurality of baffles. Fluid entering the chamber through the ports collides with the baffles, which act to reduce noise.

Abstract: A muffler for a motor vehicle has a muffler housing with a packing void into which an envelope containing a loose fill material is installed during assembly. The envelope contains elongated strands of continuous strand fiberglass, woven as a fiberglass mesh fabric, and having a thin organic polymer coating to reduce sliding and/or being formed with a Leno or gauze weave structure. The envelope is joined at one or more stitched seams, preferably with cotton thread, to enclose a volume. The volume is packed with uncoated continuous strand fiberglass roving, filling the volume to complement the packing void. The cotton thread and the thin polymer coating are consumable by hot gas in the exhaust path, but produce minimal smoke and odor due to their compositions and the small proportion of the packing volume and surface area that the consumable portions occupy.

Abstract: A muffler shell (1) for use in an exhaust system of a vehicle comprises an inner metal sheet (13) and an outer metal sheet (10). The outer metal sheet (10) is arranged to enclose the inner metal sheet (13). The muffler shell further comprises a vibro-acoustical dampening material (14) sandwiched between the inner metal sheet (13) and the outer metal sheet (10). Both the inner metal sheet (13) and the outer metal sheet (10) are corrugated sheets made of stainless steel having a thickness in the range of 0.15 mm to 0.30 mm. The vibro-acoustical dampening material has a thickness (T) in the range of 4 mm to 8 mm and a density in the range of 130 kg/m3 to 160 kg/m3.

Abstract: An aeroengine exhaust cone is arranged to extend from upstream to downstream along a longitudinal axis. The cone comprises a structural core of composite material made up of an axisymmetric part having an upstream endpiece at its upstream end and a downstream endpiece at its downstream end. The core provides structural strength to the cone. The cone has an acoustic attenuation system made of composite material and fastened on the structural core.

Abstract: An adsorption unit for combustion gas of an internal combustion engine has an adsorption housing having a chamber section with an inner wall. An adsorption element disposed in the adsorption housing is made of a gas-permeable adsorption medium that is formed to a hollow body and encloses an interior of the adsorption element. The hollow body has opposed open ends. A main flow passage extends through the hollow body and the combustion gas flows in main flow direction through the hollow body. The adsorption element has an exterior circumferential side facing away from the interior and delimiting together with the inner wall of the chamber section a bypass chamber surrounding the absorption element outwardly. In the main flow direction, the bypass chamber has a downstream end that is closed off and an upstream end that has at least one bypass opening that communicates with the main flow passage.

Abstract: A mat member includes inorganic fibers, a first surface and a second surface opposite to the first surface. The first surface has a plurality of needle penetration marks and/or a plurality of needle protrusion marks. The second surface has a plurality of needle protrusion marks and/or a plurality of needle penetration marks. A plurality of needle marks are formed in the mat member by needle punching and extend from the needle penetration mark to the needle protrusion mark. An inorganic fiber bundle which includes a plurality of the inorganic fibers oriented in a closed loop configuration is formed at the needle protrusion mark.

Abstract: A muffler providing a compact and low-profile form factor for small two-stroke engines is described, particularly useful for aerodynamic radio controlled aircraft. The muffler comprises a tuned internal header eliminating the need for an external header to mount the inventive muffler to the exhaust port of a two-stroke engine while maintaining enhanced engine performance, obviating the need for a conventional tuned-pipe exhaust.

Abstract: A muffler for a motor vehicle has a muffler housing with a packing void into which an envelope containing a loose fill material is installed during assembly. The envelope contains elongated strands of continuous strand fiberglass, woven as a fiberglass mesh fabric, and having a thin organic polymer coating to reduce sliding and/or being formed with a Leno or gauze weave structure. The envelope is joined at one or more stitched seams, preferably with cotton thread, to enclose a volume. The volume is packed with uncoated continuous strand fiberglass roving, filling the volume to complement the packing void. The cotton thread and the thin polymer coating are consumable by hot gas in the exhaust path, but produce minimal smoke and odor due to their compositions and the small proportion of the packing volume and surface area that the consumable portions occupy.

Abstract: A component of an exhaust system for a combustion engine, particularly of a motor vehicle, which at least in part regions includes a self-supporting jacket. The jacket includes a porous, open-pore or closed-pore cellularly constructed foam. The foam is of a self-supporting design. By using such a foam the insulation of the component can be improved.

Abstract: An exhaust device of an engine includes an exhaust pipe connected to the engine, a silencer connected to the exhaust pipe and structured of an outer cylinder and an inner cylinder in which plural holes are formed, and a sound absorbing material disposed in a space formed between the inner cylinder and the outer cylinder. The exhaust device further includes a partition wall partitioning the space and supporting the sound absorbing material so that the sound absorbing material does not move in an axial direction of the silencer, and the partition wall includes a continuous hole allowing exhaust gas to flow through an upstream side to a downstream side of the partition wall in the space.

Abstract: An engine-driven power generator apparatus, which includes, within a case, an engine and a power generator drivable with the engine, and in which an operation panel is provided on a front cover and an air intake louver for introducing air into the case is provided within the case, includes: a waterproof cover covering the operation panel and the air intake louver; an air guide passage of a labyrinth shape provided within the waterproof cover and communicating the outside of the waterproof cover with the air intake louver; and a brush-shaped water separation unit provided in the air guide passage and having a plurality of pins projecting in a direction intersecting flows of air in the air guide passage.

Abstract: The present application relates in a first aspect to a muffler insert for motor vehicles, in particular for passenger cars and motor trucks. This muffler insert in the form of a shaped material made from glass fiber material is in this case present in the form of a wound continuous glass fiber material, the glass fiber material used comprising a textured glass fiber. In a further aspect, the application is aimed at a method for producing such a muffler insert, a glass fiber material being wound as continuous glass fiber, which is a textured glass fiber, around a carrier in order to form a shaped material, and this shaped material being used as a muffler insert, if appropriate after further processing steps.

Abstract: A muffler for a vehicle may include a main muffler in front of a rear suspension when viewing from a front of the vehicle, a plurality of baffles dividing an interior of the main muffler into a plurality of chambers, an inlet pipe installed substantially at an center of one side of the main muffler and passing through the plurality of the baffles, a discharge pipe installed at a lower side of the other side of the main muffler and passing through the plurality of the baffles, wherein the discharge pipe exhausts an exhaust gas flowed in the inlet pipe to an exterior of the main muffler, an intermediate pipe in fluidic communication with an outlet port of the inlet pipe, and a variable valve selectively opened or closed in response to a back pressure of the exhaust gas from an outlet port of the intermediate pipe.

Abstract: An exhaust system for an engine includes an exhaust pipe connected to an exhaust port of an engine and a muffler attached to the exhaust pipe and configured to reduce exhaust noise. The muffler includes an inner cylinder part connected to the downstream end of the exhaust pipe, an outer cylinder part configured to cover an outside of the inner cylinder part and noise absorbing materials disposed between the inner cylinder part and the outer cylinder part. A plurality of first communication holes providing communication between an inside and an outside of the inner cylinder part is formed in an upstream portion of the inner cylinder part. A plurality of second communication holes providing communication between the inside and the outside of the inner cylinder part is formed in a downstream portion of the inner cylinder part. Guide walls extend toward the inside of the inner cylinder part.

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 muffler for a vehicle may include a main muffler in front of a rear suspension when viewing from a front of the vehicle, a plurality of baffles dividing an interior of the main muffler into a plurality of chambers, an inlet pipe installed substantially at an center of one side of the main muffler and passing through the plurality of the baffles, a discharge pipe installed at a lower side of the other side of the main muffler and passing through the plurality of the baffles, wherein the discharge pipe exhausts an exhaust gas flowed in the inlet pipe to an exterior of the main muffler, an intermediate pipe in fluidic communication with an outlet port of the inlet pipe, and a variable valve selectively opened or closed in response to a back pressure of the exhaust gas from an outlet port of the intermediate pipe.

Abstract: A system for improved exhaust evacuation from an internal combustion engine made up of a core which is surrounded by an outer casing, an elongated tube, and a perforated chamber made up of two cup shaped portions. The first cup shaped portion is connected to an outlet tube and the second cup shaped portion is connected to the elongated tube. The second cup shaped portion has holes around the connection and the first cup shape portion does not.

Abstract: A muffler providing a compact and low-profile form factor for small two-stroke engines is described, particularly useful for aerodynamic radio controlled aircraft. The muffler comprises a tuned internal header eliminating the need for an external header to mount the inventive muffler to the exhaust port of a two-stroke engine while maintaining enhanced engine performance, obviating the need for a conventional tuned-pipe exhaust.

Abstract: A nozzle for delivering texturized fibrous material into a chamber of a muffler has a body including a texturized fibrous material passageway and a separate directional jet passageway. A method of filling a chamber of a muffler with texturized fibrous material includes the steps of extending a wand into the muffler so that a nozzle on the wand is received in the chamber, discharging a stream of texturized fibrous material into the chamber from a first passageway of the nozzle and discharging a directional jet into the stream of texturized fibrous material from a second passageway of a nozzle whereby the stream of texturized fibrous material is redirected into a desired filling direction to more efficiently fill the chamber.

Abstract: A method for manufacturing a sound absorber, the outer wall of which is provided with a plurality of recesses, with funnel-like cone elements each being assigned to the recesses inside the sound absorber, said cone elements having a larger opening facing radially outwards and a smaller opening facing radially inwards, with adjacent cone elements each being provided on a strip-shaped first carrier band, with cup elements being provided radially on the inside relative to the cone elements, and each cup element receiving one cone element, with adjacent cup elements each being provided on a strip-shaped first carrier band, with the first carrier bands being arranged adjacently in a first direction, and the second carrier bands being arranged adjacently in a second direction, with the directions crossing each other and the carrier bands being joined to one another and to the outer wall to form a rigid body.

Abstract: A horizontally installed muffler may include a housing, first and second tail pipes installed to front and rear ends of the housing through the housing, an introduction chamber formed inside the housing and to which an outlet of the exhaust pipe is connected, a first intermediate pipe fluid-connected to the introduction chamber and having a first discharge hole, a discharge chamber fluid-connected to the introduction chamber through the first discharge hole of the first intermediate pipe, wherein each end of the first and second tail pipes and the first discharge hole are disposed inside the discharge chamber, first and second resonance chambers formed inside the housing, a second intermediate pipe fluid-connected to the first and second resonance chambers through the discharge chamber and the introduction chamber and having an introduction hole disposed inside the introduction chamber and a second discharge hole disposed inside the discharge chamber.

Abstract: A double-walled exhaust system component having glass bubbles disposed between inner and outer pipes and method of making the same. The glass bubbles have a size distribution wherein, on a bulk volume basis, at least 90 percent of the glass bubbles have a size of less than 150 micrometers.

Abstract: A horizontally installed muffler may include a housing, first and second tail pipes installed to front and rear ends of the housing through the housing, an introduction chamber formed inside the housing and to which an outlet of the exhaust pipe is connected, a first intermediate pipe fluid-connected to the introduction chamber and having a first discharge hole, a discharge chamber fluid-connected to the introduction chamber through the first discharge hole of the first intermediate pipe, wherein each end of the first and second tail pipes and the first discharge hole are disposed inside the discharge chamber, first and second resonance chambers formed inside the housing, a second intermediate pipe fluid-connected to the first and second resonance chambers through the discharge chamber and the introduction chamber and having an introduction hole disposed inside the introduction chamber and a second discharge hole disposed inside the discharge chamber.

Abstract: A muffler providing a compact and low-profile form factor for small two-stroke engines is described, particularly useful for aerodynamic radio controlled aircraft. The muffler comprises a tuned internal header eliminating the need for an external header to mount the inventive muffler to the exhaust port of a two-stroke engine while maintaining enhanced engine performance, obviating the need for a conventional tuned-pipe exhaust.