Abstract: A device for reducing the jet noise of a turbine engine includes an outer cover having an inside wall defining the outside of an annular passage for passing a bypass stream from the engine, the wall of the outer cover including a plurality of microjet circuits, each including intakes for taking a gas stream from the bypass stream flow passage and leading to a single feed duct, which in turn opens out into the trailing edge of the outer cover via at least one ejection grating suitable for splitting the intake gas stream into a plurality of gas streams of right sections of dimensions less than a right section of the feed duct.

Abstract: An afterbody for a turbojet engine having a central axis, provided with a nozzle comprising two doors facing each other between two lateral beams. The doors pivot around axes defining a pivot direction, between a retracted position, in which a middle portion of the downstream edge of the doors forms the edge of the outlet section of the nozzle combined with the downstream edges of the two lateral beams, and a deployed position, in which the middle portions of the downstream edges of the pivoting doors come together so as to block the channel between the two lateral beams in order to reverse the thrust of the turbojet engine gases. The edge of the outlet section of the nozzle further having a crown of noise-reducing chevrons alternating with indentations and the afterbody.

Abstract: An exhaust impingement cooling device for reducing heating effects of an exhaust plume on an impinged surface. An exhaust nozzle exit screen is positioned across an exhaust plume flow path, and includes a plurality of flowpath diverging apertures that spread at least a portion of an exhaust plume that is being emitted along the exhaust plume flow path from an exhaust plume source. Flow control jets are arrayed within the exhaust plume flow path in respective positions where their operation will augment the flow of exhaust plume gases through the screen, thereby increasing the momentum and mixing of the exhaust plume with cooler ambient air.

Abstract: A tail trim assembly for an exhaust pipe in a vehicle which may be mounted at a rear portion of the exhaust pipe that may be formed at an end of a vehicle muffler and discharges exhaust gas and condensed water from the muffler to the outside, may include a main body fitted around the rear portion of the exhaust pipe, at least a welding part formed at an end of the main body and welded to the exhaust pipe, and a collecting part formed at a rear end of the main body, wherein the rear end of the main body and a rear end of the rear portion in the exhaust pipe may be spaced with a predetermined gap to collect the condensed water discharged from the exhaust pipe therethrough.

Abstract: A nozzle allowing the reduction of noise generated by aircraft jet engines having at least one output ring which disturbs the propulsion jet, and having at least one pair of conduits from which the propulsion of jet air is ejected at the output of the nozzle. The conduits of each pair are disposed convergent with respect to each other in order to generate a triangle of interaction of the air jets at the output ring.

Abstract: A duct 26 has circumferentially distributed features capable of scattering acoustic energy associated with fluid dynamic shocks 34 extending in a shock orientation direction D. Each feature is oriented, over at least a portion of its length, substantially perpendicular to the shock orientation direction. The features may be splices 42 used to connect segments of an acoustic liner 30, partitions 56 in a stability enhancing casing treatment 32, or other features capable of scattering acoustic energy associated with shocks.

Abstract: Flow restrictors for aircraft inlet acoustic cores, and associated systems and methods are disclosed. A system in accordance with one embodiment of the invention includes an inlet flow surface having multiple openings, and an acoustic treatment positioned adjacent to the inlet flow surface. The acoustic treatment can have multiple cells in fluid communication with the openings in the inlet flow surface. A fluid collector passage can be positioned to collect liquid entering the acoustic treatment through the multiple openings, and can have an exit aperture through which the liquid drains. The fluid collector passage can include at least one flow restrictor positioned to at least restrict the flow of air from the exit aperture through the fluid collector passage to the multiple openings.

Abstract: A device for reducing engine exhaust noise in an aircraft engine includes a number of oscillating jets which direct an oscillating flow into the engine exhaust. The oscillating jets are connected via channels to a turbomachinery source of high pressure gas, where the source is located upstream from the engine exhaust portion. The high pressure gas passes through the oscillating jets, which have a nozzle with a triangular shaped orifice and an exhaust pipe, and exits the oscillating jets having a oscillating flow. The oscillating flow mixes with the engine exhaust thus reducing the noise created by the engine exhaust.

Abstract: A fogging device (26) for introducing water and/or vapor into an intake air flow (10, 27) of a gas turbine (1–3) includes a sound-absorbing device (31, 35). This device may in particular be designed in the form of Venturi tubes (31), the water (29) being fed to the air flow (27) via nozzles (33) arranged at the narrowest location. In this way, the spraying of water for increasing the power output or for generally regulating the gas turbine can at the same time be combined with a silencer, and this in a comparatively simple construction.

Abstract: A silencer (25a) for the attenuation of noise occurring in an intake airstream (10, 27) of a gas turbine (1–3) includes a device or devices (31, 32, 33, 34) for the introduction of water and/or steam into the intake airstream (10, 27). These devices may be designed, in particular, in the form of Venturi tubes (31), the water (29) being supplied, in particular above the saturation limit, to the airstream (27) via nozzles (33) arranged at the narrowest point. In this way, the silencing can be combined at the same time with the introduction of water for increasing the power output or for the general regulation of the gas turbine, this being achieved with a comparatively simple design.

Abstract: An engine includes at least one pulse detonation chamber configured to receive and detonate a fuel and an oxidizer. The pulse detonation chamber has an outlet end and includes a porous liner adapted to fit within an inner surface of the pulse detonation chamber within a vicinity of the outlet end. The engine also includes a casing housing the pulse detonation chamber.

Abstract: The invention relates to an exhaust system for watercraft, having an exhaust pipe which leads from an engine system to an exhaust gas outlet, wherein a through-flow means for degrading the energy of seawater gushing through the exhaust gas outlet into said exhaust pipe is provided in the section of said exhaust pipe preceding the exhaust gas outlet, and that at least one settling basin is provided in the area of said means for degrading the energy of seawater, or upstream thereof in the direction of exhaust gas flow, and a drainage conduit leads from the deepest point of the settling basin into the surroundings of the vessel.

Abstract: A cooling tower sound attenuation apparatus having at least one sheet. The sheet has an upper and lower end and a first substantially straight region and a second region that is connected to the first substantially straight region. The apparatus additionally has a liquid collection basin along with a support structure that supports the sheet such that the lower end of the sheet is proximate to the liquid collection basin.

Abstract: A suction muffler in a reciprocating compressor is installed over a suction valve to attenuate complex sound pressure (noise) such as vibrational noise, valve sonance, flowing noise and pulsative noise produced from the suction valve when low temperature, low pressure refrigerant gas ejected from an evaporator is sucked into a cylinder via the suction valve and a suction portion of the cylinder. A Tesla valve having two distribution paths is mounted in the suction muffler to attenuate the complex sound pressure (noise) while preventing the reflow of the refrigerant gas into the suction muffler from the suction valve. As a result, the Tesla valve also enhances the cooling ability of the compressor and the attenuation effect.

Abstract: A marine engine muffler is provided having a silencing element with an inclined surface defining an array of elongate slotted apertures generally disposed in circumferential alignment. The slotted apertures are preferably defined by angled sidewalls such that exhaust gas flowing therethrough is forced to travel in a path that forms a reverse angle relative to the overall exhaust flow path thus conducting exhaust gases and entrained water to reverse direction while flowing through the silencing element. The conical silencing element is specifically sized to avoid resonant vibration within the operational RPM range of the engine and is further sized relative to the combined displacement of the engine and/or cylinder bank in fluid communication therewith to avoid resonant vibrations caused by reflected exhaust gas pressure waves generated by the internal combustion engine.

Abstract: A device for catalytic removal of a pollutant from an exhaust gas of a combustion system, particularly, a fossil-fired power plant or an internal combustion engine, includes an exhaust-gas duct for carrying exhaust gas, a reagent, a muffler having an injection space and a mixing space for mixing the reagent with the exhaust gas, an injection device for introducing the reagent into the exhaust gas in the injection space, at least one catalytic converter disposed in the exhaust-gas duct, and mixers disposed at least one of before and after the injection space with respect to a direction of flow of the exhaust gas. The mixers define a distance therebetween, and the distance is matched to a frequency of sound to be damped in the exhaust gas. According to the invention, the injection chamber and the downstream mixture chamber are embodied as a muffler in order to reduce the emissions of sound while enabling the production of a device having a compact structure.

Abstract: A muffler is provided for a marine propulsion system in which an initial portion causes a downward flow of exhaust gas and entrained water from an exhaust manifold. The transition section directs the exhaust gas toward an egress section which extends upwardly from the transition section. The various sections of the exhaust path can be configured to form one or more loops which define one or more water collection regions.

Abstract: An exhaust system is provided with a structure that separates water from an exhaust stream and also attenuates the noise of the exhaust system. Water laden exhaust is directed from an inlet conduit through a perforated surface to precipitate water from the water laden exhaust stream. After the water is precipitated out of the exhaust stream, the gaseous portion of the exhaust stream continues from the inlet chamber 24 to an outlet chamber 28 and exits from the housing structure by passing through a first outlet conduit. The precipitated water passes from the housing structure through a second outlet conduit.

Abstract: Methods and apparatus for suppressing cell howl with negligible impact on engine test conditions are described. The apparatus, in an exemplary embodiment includes a flow distorter configured to be positioned close to a nozzle exit of an engine nozzle, and a flow distorter support for maintaining the flow distorter at a selected location. The flow distorter is adjustably secured to the support so that a distance at which a tip of the distorter is located relative to support is adjustable.

Abstract: A muffler for reducing fluid flow noise in a hydraulic system comprises a cylindrical elastomer insert having multiple reinforced flow ports with different diameter porting, internal air chambers, and cast from an elastomer mixed with hollow glass spheres to form an insert of 40 percent air by volume. The insert is placed within a housing and connected to the hydraulic pipe assembly for receiving fluid under pressure and diverting it through the multiple flow ports of the insert wherein flow sounds, pump surges, and flushing noises of the hydraulic system are muffled by the disruption of the flow through the flow ports, the absorption by the internal air chambers, and the absorption by microspheres created by the hollow glass spheres in the elastomer insert.

Abstract: A muffler for reducing fluid flow noise in a hydraulic system comprises a cylindrical elastomer insert having multiple reinforced flow ports with different diameter porting, internal air chambers, and cast from an elastomer mixed with hollow glass spheres to form an insert of 40 percent air by volume. The insert is placed within a housing and connected to the hydraulic pipe assembly for receiving fluid under pressure and diverting it through the multiple flow ports of the insert wherein flow sounds, pump surges, and flushing noises of the hydraulic system are muffled by the disruption of the flow through the flow ports, the absorption by the internal air chambers, and the absorption by microspheres created by the hollow glass spheres in the elastomer insert.

Abstract: An exhaust muffler for marine engines comprises a cylindrical container arranged to be mounted with its longitudinal axis horizontal and traverse to the longitudinal axis of the engine. The container forms an expansion chamber, which is closed at one or both ends by an end piece (23) depending of whether it is used on engines with one or two rows of cylinders. The end piece has an inlet (26) and an outlet (27) for exhaust gas and intermediate flow diverting baffles (50,51).

Abstract: The invention provides a device for collecting the exhaust gas jet of an aircraft reactor with orientable propulsion nozzle or with a gas jet orientable with respect to the longitudinal axis of said reactor, during ground testing of the latter, as well as a testing installation for aircraft reactors equipped with said device. The device comprises an external cylindrical jacket bell-mouthed at its end intended to be situated opposite the tested reactor and a cylindrical internal jacket, concentric to said external jacket and intended for straightening out the exhaust gas jet when this latter or the propulsion nozzle of the tested reactor has a slant with respect to the axis of said reactor.

Abstract: An exhaust muffler for a marine engine comprises a first vertically oriented tubular member having a lower end sealingly extended through the bottom of a main body chamber and an upper end extending upwardly through the top of the chamber. A second tubular member surrounds and is spaced from the first tubular member for forming a passage therebetween, and has its upper end sealingly extended through the top of the chamber and its lower end extending to a point below two chamber inlets, yet spaced from the bottom of the chamber. A cap seals the upper end of the second tubular member to invert upwardly flowing exhaust gases and cooling fluid within the passage between the first and second tubular members downwardly into the first tubular member for discharge from the muffler.