Abstract: An exhaust system for a snowmobile includes a muffler housing, the bottom end of the muffler housing including a muffler exhaust outlet configured to emit exhaust. The exhaust system includes a muffler housing cover spaced from the muffler housing to define an airflow channel therebetween, the muffler housing cover forming a bottom opening. The exhaust system also includes a gas combiner at least partially surrounding the muffler exhaust outlet on the bottom end of the muffler housing and extending through the bottom opening of the muffler housing cover. The gas combiner receives air from the airflow channel and the exhaust from the muffler exhaust outlet to emit a combined air-exhaust stream.

Abstract: The invention presented is a crossover section for a vehicle exhaust system that includes a middle pipe and two outer pipes, each outer pipe in contact with and attached to the middle pipe. Diversion gates extend from the middle pipe into each of the outer pipes to divert a sample of exhaust gas into the middle pipe. A sensor, such as an oxygen sensor, is provided to measure one or more components of the combined exhaust. Also provided is an exhaust system that includes the inventive crossover section and a vehicle that includes one or more of the inventive exhaust systems.

Abstract: A muffler for exhaust gases of a combustion engine includes walls forming a chamber through which the exhaust gases pass, a first inlet in the walls of the chamber configured to receive the exhaust gases from an exhaust duct of the engine, a first outlet in the walls of the chamber through which the exhaust gases exit the chamber, and a conduit having a second inlet and a second outlet, wherein a substantial length of the conduit is positioned within the chamber.

Abstract: A Tier 4 ready silencer that can accept both DOCs and DPFs to meet Tier 3 and can interface with an SCR system to meet Tier 4. The invention includes a silencer compartment with empty filter/catalyst banks in the shape of a V. DOCs and DPFs can be added and arranged in the V-shaped banks as needed. Various exhaust fins direct exhaust flow through the filters/catalysts. Multiple exhaust inlets to the device provide the most direct route possible from the engine outlets. A mixing tube and an SCR system can be added to the output port to comply with Tier 4.

Abstract: A muffler for a combustion engine includes walls forming a chamber, a first inlet, a first outlet, and a conduit. The first inlet is designed to receive exhaust gases from an exhaust duct of the engine. The exhaust gases pass through the chamber when moving from the first inlet to the first outlet. The exhaust gases then exit the muffler through the first outlet. The conduit extends between a second inlet and a second outlet. The second inlet is configured to receive fresh air entering the muffler. The fresh air then exits the conduit and is introduced into the exhaust gases through the second outlet.

Abstract: An exhaust gas-cooling device for use on an exhaust gas conveyance system of a vehicle having an exhaust gas passageway to emit exhaust gases from an engine to an outlet includes an exhaust passageway pipe in fluid communication with the engine, and a micro-venturi mixing chamber pipe in fluid communication with and located downstream of the exhaust passageway pipe. The micro-venturi mixing chamber pipe defines the outlet of the exhaust gas-cooling device and has at least one aperture disposed on a pipe body of the micro-venturi mixing chamber for introducing ambient air into the micro-venturi mixing chamber pipe.

Abstract: In a method for adjusting a Helmholtz resonator (10), in which a resonator volume (11) is connected to a space (13) to be provided with damping along an axis (29) via a constriction (12) having an acoustic impedance, the acoustic impedance of the constriction (12) is altered in order to adjust the Helmholtz resonator (10).

Abstract: A marine muffler comprises an elongate cylindrical housing having an inlet and an outlet and defining an internal volume partitioned, by an angularly disposed internal baffle, into a lower chamber in communication with the inlet and an upper chamber in communication with the outlet. A vertically disposed duct is insertably secured to the baffle to allow exhaust gas and exhaust cooling water to flow from the lower inlet chamber to upper outlet chamber. The exhaust duct may preferably be further adapted with internal structure forming a plurality of individual flow conduits or passages. The duct is preferably positioned such that a plurality of flow passage inlets are positioned in proximity to the lower cylindrical housing wall, with flow passage outlets positioned in proximity to the upper housing wall. The lower duct wall may further be adapted with sidewall apertures for improving exhaust flow dynamics therethrough.

Abstract: A muffler for a small two-cycle engine includes: a muffler body having an expansion chamber; an exhaust-gas guide member covering an outlet for exhaust gas, the outlet being provided on the muffler body and a cover hood that covers a discharge port for exhaust gas, the discharge port being provided on the exhaust-gas guide member. A guide that guides the exhaust gas in the exhaust-gas guide member is gradually widened toward a top surface of the cover hood as proceeding to the discharge port.

Abstract: A plurality of pellets include at least one of a snythetic, biomass, mineral, or polymer based material. The pellets can have a specific gravity of about 0.01 to about 0.3 g/cm3 and are dimensionally stable, substantially dust-free, substantially non-hygroscopic, and resistant to settling and compression.

Abstract: A system for dampening sound produced by an air blower such as that used to inflate an inflatable movie screen or other inflatable structures. The system can include an air blower and a muffler. The muffler is configured to reduce or dampen sound output from the air blower and includes one or more surfaces that enclose at least a portion of the blower. An opening may be formed in the muffler to facilitate air flow into the air blower. The blower can include a fan and the opening may allow air to pass through into a space in the interior of the muffler and to the fan, so that it can be output to the inflatable movie screen. The muffler may also include a second opening. The second opening can facilitate output of the air by the blower and to the inflatable movie screen.

Abstract: In an acoustic fluid machine, an acoustic resonator gradually reduces in diameter towards the top on which a valve device is provided to suck a gas into the resonator. The gas is compressed in the resonator by a circular-plate piston at the lower end of the resonator and discharged via an outlet of the valve device. The piston comprises a rubber plate fixed to the resonator and a metal plate attached on the rubber plate.

Abstract: The invention relates to a cowl for a turbomachine nozzle, the cowl including a plurality of repetitive patterns disposed to extend a trailing edge of said cowl and spaced circumferentially apart from one another. Each pattern is in the form of a quadrilateral having a base that is formed by a portion of the trailing edge of the cowl and two vertices that are spaced downstream from the base and that are connected thereto via two sides, each side having the shape of a parabola. Each pattern is asymmetrical relative to a midplane of the pattern containing a longitudinal axis of said cowl, and it comprises a first portion inclined radially towards the inside of the cowl, and a second portion inclined radially towards the outside of the cowl.

Abstract: An inlet door assembly and method for reducing noise from an auxiliary power unit (APU) contained within an aircraft housing is provided. The inlet assembly includes an inlet duct, an actuator, and a door. The inlet duct is configured to extend from the auxiliary power unit to the aircraft housing and has a sidewall that defines a flow passage through which APU noise propagates. The actuator is disposed at least partially within the inlet duct. The door coupled to the actuator. The actuator is also configured to selectively rotate the door between at least a first position, in which at least a portion of the door deflects APU noise in a first direction, and a second position, in which at least a portion of the door deflects the APU noise in a second direction.

Abstract: A vehicular exhaust resonator features an exhaust inlet conduit which narrows down in a manner such as to define a venturi effect region. Air entrainment apertures in the housing of the resonator provide fluid communication between outside cooling air and an air inlet chamber in the resonator. A further air inlet aperture in an outlet conduit section of the resonator is in fluid communication with the air inlet chamber. Due to the venturi effect inside the inlet conduit, a pressure drop is created to pull air from the outside into the air inlet chamber and then into an outlet conduit of the resonator for mixing with the exhaust gas to provide cooling thereof.

Abstract: The invention concerns a suction muffler for a refrigerating machine with a housing, in which at least one chamber is arranged and which has an inlet opening (7), an outlet opening and an oil discharge opening. It is endeavoured to avoid that too much oil remains in the chamber. For this purpose, an oil collecting room is arranged to be connected to the bottom end of the chamber, the oil discharge opening being arranged at the bottom end of said oil collecting room.

Abstract: In a fluidal machine with an impeller rotating to urge a fluid radially outwardly by a centrifugal force, a vane guiding the fluid discharged from the impeller, a vane member which includes a front end of the vane facing to the impeller so that the fluid discharged from the impeller strikes against the front end and which is prevented from contacting the atmosphere, and a casing surrounding the vane member and contacting the atmosphere, the vane member is discrete from the casing, a vibration propagation between the vane member and the casing is prevented or restrained, and a vibration of a pipe extending from the casing is absorbed.

Abstract: An exhaust system for an internal combustion engine has special accommodations for preventing the pooling of water in the passageways of the exhaust system. One or more of the components of the exhaust system such as mufflers and or sections of exhaust tubing etc. have absorbent liners disposed at points within said exhaust system where water is likely to pool. The absorbent liners wick moisture away from the inner surfaces of the exhaust components in which they are disposed. Moisture is held within the absorbent liners until the temperature of the exhaust system rises enough to evaporate the moisture at which time the water vapor exits the exhaust system with the combustion products of the internal combustion engine. The absorbent liners are of a size and shape and are positioned within the exhaust system components such that they present minimal restriction to flow of combustion products through the exhaust system.

Abstract: The invention concerns an arrangement for a discharge system for combustion gases from a motor-driven vehicle which gives the vehicle a low IR signature. According to the invention, the gas outflow channel (28), at least in an area of the channel adjacent to the discharge aperture (32), has a boundary wall (34) which is perforated right up to the open discharge aperture (32) and surrounded by a cooling air channel (38). The arrangement is such that cooling air can sweep over the inner side as well as the outer side of the perforated wall (34).

Abstract: An exhaust muffler (20) for an internal combustion engine (25) includes a tapered tube (28) and an outer tube (40) axially aligned with and surrounding the tapered tube (28) so that an annular passage (42) is formed between the tapered tube (28) and the outer tube (40). The tapered tube (28) has an exhaust inlet end (30) for receiving exhaust gases (76) from the engine (25) and an exhaust outlet end (34). The outer tube (40) has an air inlet end (50) for receiving air (49) external to the engine and an air outlet end (52). The external air (49) flows in the annular passage (42) toward the air outlet end (52). The flow of the external air (49) creates a low pressure region (54) downstream of the exhaust outlet end (34) to accelerate the receipt of exhaust gases (76) from the engine, and elliptical holes (62) in the tapered tube (28) allow the smooth flow of exhaust gases (76) from tapered tube (28) to mix with the external air (49) to achieve effective noise attenuation.

Abstract: An exhaust muffler for small marine craft that can be located in the rear portion of the bilge and straddle the drive shaft and the shaft log. The muffler has a shell formed from sides, ends, top and bottom walls. The bottom wall is provided with a concave depression to receive the shaft and shaft log. A preferred configuration of the depression is a semi-conical surface having a base proximate the inlet wall. Further, the top and bottom walls are configured to conform to the undersurface of the deck and the inside of the hull, respectively. An inlet pipe, or a multiple number of inlet pipes, receive exhaust gases and water from the exhaust manifold of the craft engine and direct this combination into the muffler above a water pool. Gases pass through the water pool and exit through an outlet pipe (or a plurality of outlet pipes). A downwardly extending conduit within the outlet pipe(s) provides a correct amount of lift such that an amount of water exits the muffler which is the same as the amount entering.

Abstract: An integral formed fluted tube intended, for example, for use as a sound suppression device in mufflers, exhaust ejectors, etc. is disclosed. The tube is formed of a cylindrical portion with generally circular inlets and outlets and a constricted portion between those ends and within the constriction, a plurality of bypasses therethrough. The constriction may also include a frontal portion having a generally concave surface which rises to an apex and thereafter forms a plurality of convex rear portions toward the outlet end. Other embodiments are shown in the Figures. The device may be used integrally within a muffler to obtain a venturi effect for an exhaust ejector and sound suppressor.

Abstract: An ejector comprising a housing (30, 81) and an ejector insert (40, 82) received therein to form a venturi which is eccentric with the housing, and a muffler-ejector assembly (25), including such an ejector (80), so mounted that the inlet axis (78) of the exhaust tube (71) may be made to approach or even coincide with the axis (59) of the casing (60) without enlarging the lateral dimensions of the latter.

Abstract: Splitter type exhaust silencers are improved by providing means for preventing dust particles from depositing upon sound deadening fibers exposed to the dust carrying exhaust gas stream by providing a dust-free boundary layer gas stream to flow protectively over the fiber and insulate the exhaust gas stream from the fiber. In alternate protective means, thin sheets or strips of strong material such as metal foil are mounted protectively near the exposed fiber which vibrate in the exhaust stream passing thereover and tend to continuously displace and/or prevent dust from settling upon the fiber. The thin sheets may be used alternately or together with the dust-free boundary layer gas stream to prevent dust deposition upon the fiber.

Abstract: A method of and a device for attenuating the noise radiated by a free-expion gas jet throughout the audible-frequency range as well as in the ultrasonic and infrasonic frequency ranges. Concomitantly with the complete and shock-free expansion of the gas into the atmosphere, the acoustic field of the jet is organized by the substantial diminution of the low-frequency tones by causing them to pass from the annular section of the jet to the narrow annular section of the nozzle slot. This is followed by sound-wave diffraction on emergence from the slot in the presence of a baffle, and by a wave reflection towards the sound-absorption lining of the device housing. The final noise results from an intensive ejection of ambient air by the primary gas which, leaving the nozzle slot, entrains the air by means of turbulence, the air entering through the annular channels of the case, reaching the outer orifices of the nozzle, and dividing into two flows, namely inside and outside the nozzle.

Abstract: A low noise level, pressure fluid spouting device includes an inlet for introducing a pressure fluid therein at one end thereof; a nozzle connected to the inlet for jetting or emitting the pressure fluid therefrom, the nozzle having an annular inner wall of a predetermined diameter as a nozzle port thereof with an enlarged portion at the other end thereof for spouting the pressure fluid from the nozzle. The enlarged portion has a predetermined length (1.sub.o) from the entrance to the exit or open end thereof, and comprises an annular inner wall of a predetermined diameter (d.sub.2) larger than that of the nozzle means as an enlarged passage communicating with the nozzle port; and an outer wall which is tapered or gradually decreased in width towards the exit or open end portion of the enlarged portion with a predetermined angle of inclination (.theta.). The wall of the enlarged portion has a predetermined thickness (t) at the exit or open end portion of the enlarged portion.

Abstract: A muffler, especially for a portable internal combustion engine, particularly for driving a motor chain saw, which muffler comprises an exhaust gas receiving chamber which is defined by a chamber wall and by a pan-shaped housing wall including an inlet for the exhaust gases. Arranged on the inside surface of the chamber wall there is arranged an exhaust gas conveying passage communicating with the exhaust gas chamber and being adapted to deflect an exhaust gas current by preferably 90.degree.. This passage is adapted to convey the thus deflected exhaust gas current through an aperture in the chamber wall. Above this aperture on the outside of the chamber wall and projecting therefrom there is provided a bend from which the exhaust gas current through an outlet in the bend flows at least approximately parallel to a portion of the chamber wall.

Abstract: Disclosed is an exhaust silencer suitable for use with portable combustion engines, and particularly for use with chain saw engines, comprising a chamber having an inlet and outlet for receiving the engine exhaust; means disposed about the chamber outlet for reducing the kinetic energy of the exhaust flowing therethrough; and an air duct means mounted exteriorly of the chamber below the chamber outlet for cooling the chamber, the kinetic energy reducing means, and the exhaust gas by contact with a stream of ambient air flowing therethrough.

Abstract: A method of and a device for attenuating the noise radiated by a free-expion gas jet throughout the audible-frequency range as well as in the ultrasonic and infrasonic frequency ranges. Concomitantly with the complete and shock-free expansion of the gas into the atmosphere, the acoustic field of the jet is organized by the substantial diminution of the low-frequency tones by causing them to pass from the annular section of the jet to the narrow annular section of the nozzle slot. This is followed by sound-wave diffraction on emergence from the slot in the presence of a baffle, and by a wave reflection towards the sound-absorption lining of the device housing. The final noise results from an intensive ejection of ambient air by the primary gas which, leving the nozzle slot, entrains the air by means of turbulence, the air entering through the annular channels of the case, reaching the outer orifices of the nozzle, and dividing into two flows, namely inside and outside the nozzle.

Abstract: An exhaust system of an internal combustion engine especially adapted for use as a power source for a portable tool such as a chain saw, said exhaust system comprising a muffler enclosed within an engine casing and located within the passage of the cooling air flow for cooling the engine, and an exhaust gas dilution system consisting of an ejector connected to the outlet of said muffler and a diffuser disposed at such a position that the outlet of said ejector is opened into the inlet of said diffuser.

Abstract: Combination muffler and catalytic converter utilizes an axial flow monolithic catalytic element to treat exhaust gases from an internal combustion engine and partially reduce their sound. A perforated chamber around the catalytic element, a downstream perforated tube, and an upstream flow reversal chamber further reduce the sound. The device incorporates a venturi in the exhaust gas inlet path to add secondary air. Gas swirling and gas flow reversal structure is also provided to thoroughly mix the secondary air with the exhaust gases before the mixture is passed through a flow distribution plate and into contact with the catalytic element.