US3685614A - Method and device for attenuating the noise generated by the expansion of gases into the atmosphere - Google Patents

Method and device for attenuating the noise generated by the expansion of gases into the atmosphere Download PDF

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Publication number
US3685614A
US3685614A US191922A US3685614DA US3685614A US 3685614 A US3685614 A US 3685614A US 191922 A US191922 A US 191922A US 3685614D A US3685614D A US 3685614DA US 3685614 A US3685614 A US 3685614A
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Prior art keywords
conduit
gas
sound
passage
nozzle
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US191922A
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English (en)
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Henri Coanda
Constantin Teodorescu
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INST PENTRU CREATRE STIINTIFIC
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INST PENTRU CREATRE STIINTIFIC
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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N1/00—Silencing apparatus characterised by method of silencing
    • F01N1/08—Silencing apparatus characterised by method of silencing by reducing exhaust energy by throttling or whirling
    • F01N1/10—Silencing apparatus characterised by method of silencing by reducing exhaust energy by throttling or whirling in combination with sound-absorbing materials
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N1/00—Silencing apparatus characterised by method of silencing
    • F01N1/14—Silencing apparatus characterised by method of silencing by adding air to exhaust gases
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04F—PUMPING OF FLUID BY DIRECT CONTACT OF ANOTHER FLUID OR BY USING INERTIA OF FLUID TO BE PUMPED; SIPHONS
    • F04F5/00—Jet pumps, i.e. devices in which flow is induced by pressure drop caused by velocity of another fluid flow
    • F04F5/42—Jet pumps, i.e. devices in which flow is induced by pressure drop caused by velocity of another fluid flow characterised by the input flow of inducing fluid medium being radial or tangential to output flow
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N2470/00—Structure or shape of gas passages, pipes or tubes
    • F01N2470/30—Tubes with restrictions, i.e. venturi or the like, e.g. for sucking air or measuring mass flow

Definitions

  • ABSTRACT A noise or sound attenuator useful for a motor vehicle internal-combustion engine has an elongated conduit which is formed at one end with a plurality of laterally opening inlets.
  • the gas is fed into the center of the conduit through an annular slot whose downstream lip is shaped to entrain the gas jet along the wall of the conduit.
  • This Coanda ejector action sucks air into the inlets to mix with the gas, while the noise of the gas being expelled is directed mostly against the flow direction into a sound absorber located in the closed upstream end of the conduit.
  • the walls of the conduit are perforated upstream and downstream of the nozzle and lined externally with sound absorbing material for best noise attenuation.
  • Attenuation of the noise generated by the expansion of gases into the atmosphere is achieved by means of active silencers, reactive silencers, multisection silencers, and silencers with depressive shutters.
  • the active silencers are basically conduits whose inner surfaces are lined with sound-absorbing material. They are built in various versions: with simple chambers, with lamellar or cellular elements, and with chambers and screens.
  • the simple chamber silencer consists of a tube made out of steel plate or similar material to which the sound-absorbent treatment may be applied only at the walls or may be dispensed with. In the latter case noise attenuation is achieved by restricting the flow and possibly cooling the gas.
  • conduits For the purpose of increasing the sound-absorbing capacity within a broader frequency range large-section conduits are divided into a series of subconduits with small dimensions by sound-absorbing plates or baffles parallel to the flow direction and arranged in line with one or both axes of the section of the conduit to form a lamellar or cellular silencer.
  • the chamber-and-screen silencer consists of one or several chambers acoustically treated and separated by means of screens arranged perpendicularly or obliquely to the path of gas flow. Noise attenuation is achieved by reflection of the acoustic waves by the screens.
  • the reactive silencer is an acoustic system whose particularity lies in the capacity to allow passage practically without attenuation of sounds of a certain frequency while damping or reflecting towards the source sounds of the remaining frequencies.
  • This acoustic system consists of several chambers successively joined to one another by tubes. Each chamber with its junction constitutes a resonator which damps within a certain frequency range.
  • the multisection silencer achieves the partial attenuation of noise by increasing the mixing of the gas stream with the surrounding air, the increase of initial turbulence being avoided at the same time. In these conditions, quick diminution of the gas velocity is attained along the jets axis along with attenuation of the lowand medium-frequency noises.
  • silencers used specially for the attenuation of the noise generated by the exhaust of internal-combustion engines.
  • the particularity of these silencers consists in the spiral or baffle form of the conduits which are provided with orifices or groups of orifices arranged in certain arrays and sometimes accompanied by deflecting cups covering the orifices. Noise attenuation by these silencers is obtained by way of the fragmentation of the gas flow and reflection of the sound waves upstream.
  • the depressive-shutter silencers achieve the attenuation of the noise by diffraction of the acoustic waves as they pass through depressive networks, the absorption of the waves which have undergone the diffraction being obtained by a sound-absorbing treatment on the lined shutters of the networks and by the intensification of the turbulent mixture of the elementary jets which leave the depressive networks with a surrounding air in the deviating process by way of the Coanda effect (see Time, p. 49, Dec. 2, 1966, and Scientific American, pp. 81 ff., December 1964).
  • the above silencers all have the disadvantage that they attenuate noise only within a very restricted frequency range, leaving unattenuated the low and the very low frequencies. In order to combat this, large overall dimensions of the silencer are necessary making its construction expensive and limiting its usability. Furthermore, in lamellar silencers, cellular silencers, and silencers with chambers and screens, the high-velocity and high-temperature gases rapidly degrade the inner elements of the silencer, putting it out of use after a short working period.
  • the depressive-shutter silencers while achieving a good attenuation of the noise within a broad frequency range present nevertheless the disadvantage of large overall dimensions and excessive complexity.
  • Another object is the provision of an apparatus for attenuating exhaust gas noise of an internal-combustion engine.
  • Yet another object is to provide such a noise attenuator or silencer which is effective over a broad frequency range, is of simple and inexpensive construction, and has a long service life.
  • the above objects are attained according to the present invention by releasing the high-pressure and high-temperature exhaust gases through an annular nozzle of a so-called Coanda ejector into the passage of a conduit.
  • the ejector which functions according to the well-known Coanda effect, entrains gases longitudinally while it is fed transversely with the fluid. More specifically this ejector has a nozzle which is so shaped that the gases tend to flow around one lip and thence travel along the conduit in one direction while the noise of the escaping gases travels down the conduit in the opposite direction, since this sound is in no way influenced by the Coanda effect.
  • the escaping gases define a flow direction in the conduit and act as a jet pump to draw air in through the upstream end of the conduit.
  • This inlet end is provided with lateral openings for air ingress while its inner surface is provided with sound-absorbing material to deaden the noises of the escaping gases.
  • a Coanda ejector will be defined as a fluid ejector wherein the entraining fluid is caused to flow through the ejector constriction, upstream of a coaxially diverging passage or chamber, by the Coanda effect adhesion of the boundary layers of fluid to the surface of the constriction which, as already noted, form an outwardly turned annular lip defining a slot into which the fluid is introduced transversely. Consequently, air or other sound-damping, temperature-reducing and diluting fluid is caused or induced to flow through the constriction and is entrained by the Coanda effect fluid hugging the walls of the Coanda ejector.
  • the transverse introduction of the Coanda effect fluid constitutes a direction change and velocityreducing type of absorber because, while the fluid passes along the walls of the Coanda ejector by a direction change attributable to the Coanda effect, noise or sound propagation continues with the direction substantially unchanged until it is intercepted by the transverse flow of air passing longitudinally through the passage. While air is induced to flow through the ejector because of the Coanda entrainment, a pressure differential is established across the constriction because of the ejector effect with the relatively high-pressure side upstream.
  • Both the movement of the air through the ejector and this somewhat elevated pressure constitute a sound interference barrier causing substantial noise attenuation apart from the attenuating effect of the sound-absorbing material at the upstream side of the ejector and the perforations in the wall of the passage at this upstream side.
  • any sound transmitted in the longitudinal direction of flow of the Coanda fluid is attenuated by the relatively long flow path and the sound-absorbing material lining same.
  • the method according to the invention envisages in a first phase the expansion of the gases within a Coanda inner-type ejector, such that simultaneously with throttling of the jet, structural modification of the acoustic spectrum and its direction takes place, as well as a substantial lessening of its velocity, of its temperature, and of the concentration of its gases, a process continued in a second phase by the absorption of the acoustic waves by two active silencers mounted upstream and downstream of the inner-type Coanda ejector.
  • the device consists of a convergent inlet nozzle for air connected to an inlet attenuator of decreasing cross-sectional area, an inner-type Coanda ejector followed by a diffuser, an outlet attenuator and a discharge nozzle.
  • the converging inlet nozzle which is formed by a network of laterally opening slits and a converging channel, has a damping screen placed at an adequate distance such that the penetration of the surrounding air through the slit network is possible, while the propagation of noise of the ejector is impossible.
  • the Coanda ejector has an annular chamber into which the exhaust gases are fed through a pipe, and whence they pass through an annular slit in the shape of a jet, the gases adhering to the wall or surface of the converging part of the Coanda ejector, flowing along a neck to the inferior part of the outlet diffuser, and thence to the outlet attenuator end of the discharge nozzle.
  • Sound-absorbing walls similar to those of the inlet nozzle and of the damping screen are provided in the outlet side of the apparatus.
  • the device according to the invention is formed of an inlet nozzle 1 for the inspired air, an inlet attenuator 2, a Coanda ejector 3 of the inner type, an outlet attenuator 4, and a discharge nozzle 5.
  • the inlet nozzle 1 of the ejected air is made of a network of laterally opening slits 6, a converging channel 7, and a damping screen 8. This nozzle ll insures the entry of the surrounding air into the device and hinders the propagation of the ejectors noise to the exterior.
  • the inlet attenuator 2 is a conduit of circular or rectangular section whose walls are perforated and lined externally with sound-absorbing material.
  • the length of the conduit and the type of acoustic material being dictated by the attenuation degree required.
  • the inner-type Coanda ejector 3 consists of an annular chamber 3a, having a lip 9 formed continuously with a cylindrical neck 10, downstream of which is provided a diffuser 11.
  • the converging part 9 is precided by an annular slit 3b through which is discharged the gas under pressure arriving in the annular chamber 30 through a pipe 12.
  • the outlet attenuator 4 is similar to the inlet attenuator 2, its geometry being determined by the diameter of the downstream end of the diffuser l l and the type of noise generated by the annular jet at the planar annular slot or nozzle 3b.
  • the discharge nozzle 5 is a diffuser whose shape is determined according to the shape of the inner-type Coanda ejector 3 and by the parameters of the expansion gases.
  • the drawing also shows that the inlet pipe 12 opens radially'into the annular chamber 3a which is defined by a ring 20 into which the tube 12 is welded and which, in turn, is welded to the nozzle-forming ring 21.
  • the interior of the latter defines the Coanda constriction and surface 22 which, in combination with the axially outwardly divergent wall ll, forms a laval-type nozzle.
  • the wall 11 and the ring 20 are shown to be surrounded by the body 23 of sound-absorbing material within the cylindrical sheet-metal casing l and to be nonperforated.
  • the sound-absorbing material which may be a fleece or wool of refractory sound-absorbing materials, e.g. asbestos fiber or glass wool.
  • the housing 1 is assembled by bolting together at 24 a pair of flange rings 25 and 26, respectively welded to the housing sections 27 and 28, these rings serving also as supports for the Coanda ejector.
  • the Coanda ejector 3 is bolted at 28 to the inner portion of the ring 26 which serves as a spacer supporting the perforated cylindrical metal wall 2 which, as illustrated, is surrounded by a body of the sound-absorbing material represented at 29.
  • This body of sound-absorbing material is separated by an annular partition 30 from the annulus 31 of sound-absorbing material surrounding the rearwardly outwardly flared unperforated intake cone 7 previously described.
  • a reinforcing end support ring 32 in which the sound-absorbing wall 8 is mounted.
  • This wall comprises a sheetmetal disk 33 retaining the layer 34 of sound-absorbing material within the flat cylindrical housing 35 whose face, turned toward the passage, is provided with the perforated wall 36.
  • Another reinforcing and mounting ring 37 at the opposite end of the sound-absorber supports a sheetmetal disk 38 which, in turn, carries the downstream end of the frustoconically diverging outlet-conduit portion 5 which, as illustrated, is formed with perforations 39.
  • the cylindrical conduit section 4 immediately upstream thereof is provided with perforations 40 and both conduit sections are surrounded by the body 23 of sound-absorbing material.
  • the device works as follows:
  • the gases which are to be discharged into the atmosphere are directed by means of the pipe 12 into the annular chamber 3a and from here they traverse the annular slit 3b in the form of an annular jet. Due to the Coanda effect the annular gas jet adheres to the surface of the converging nozzle 9, passes up over the neck 10, and creates within the restriction at this intermediate conduit region a violent sucking-in of the upstream air.
  • the gases or steam mix with the cold air, cool intensely, and advance through the diffuser l1 and the outlet attenuator 4 with a substantially reduced velocity. From the outlet attenuator 4 the gas and air mixture passes into the discharge nozzle 5 where it is throttled further because of the gradual increase of the transverse crosssection, and from here it is discharged into the atmosphere.
  • the passage of the gases transversely through the annular slit 3b determines the change of the structure of the noise generated by the free jet by displacing the acoustic spectrum into the range of the high and of the very high frequencies which can easily be attenuated by the sound absorbing portions 2, 4, 5, and 8 of the device.
  • the deviation of the annular jet within the ejector 3 is not followed by its noise so that the predominant components of this noise are directed towards the sound absorber 8 of the entry attenuator. In this way the acoustic energy of the incident waves is quickly dissipated along with the noise propagated downstream of the device.
  • the present invention offers the following advantages: it achieves a strong attenuation within the whole audible frequency range, it has both constructive and working simplicity, it has small dimensions and requires a minimum of materials, it has a long service life, and it diminishes the polluting effect of the escaping gases.
  • a method of attenuating the sound of a gas released under pressure into the atmosphere comprising the steps of:
  • An apparatus for attenuating the sound of a gas released under pressure into the atmosphere comprising:
  • conduit forming an elongated passage open at both ends to the atmosphere
  • means including an annular transversely open nozzle for feeding said gas under pressure transversely into said passage;
  • conduit has a closed upstream end and an open downstream end, said conduit being formed with at least one transversely open inlet at said upstream end and being outwardly tapered from said surface to said downstream end.
  • conduit includes an outwardly divergent diffuser section immediately downstream of said nozzle, a perforated cylindrical outlet attenuator section immediately downstream of said diffuser section and surrounded by said body, and an outwardly flared discharge nozzle section opening directly into the atmosphere and immediately downstream of said attenuator section, said discharge section being perforated and being surrounded by said body.
  • conduit further comprises a perforated cylindrical inlet attenuator section surrounded by said body and disposed immediately upstream of said nozzle, and a rearwardly flared section communicating with and immediately upstream of said inlet attenuator section, said apparatus further comprising a cylindrical inlet immediately upstream of said rearwardly flared section and provided along its periphery with a multiplicity of axially extending slits communicating between the atmosphere and said conduit, and a sound-absorbing wall IO

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Exhaust Silencers (AREA)
  • Jet Pumps And Other Pumps (AREA)
US191922A 1970-10-26 1971-10-22 Method and device for attenuating the noise generated by the expansion of gases into the atmosphere Expired - Lifetime US3685614A (en)

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RO64778A RO53910A2 (fr) 1970-10-26 1970-10-26

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US (1) US3685614A (fr)
CS (1) CS150921B2 (fr)
DE (1) DE2126654C3 (fr)
FR (1) FR2109611A5 (fr)
GB (1) GB1349194A (fr)
HU (1) HU166109B (fr)
RO (1) RO53910A2 (fr)

Cited By (25)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3794137A (en) * 1971-12-13 1974-02-26 Inst Pentru Creatie Stintific Device for attenuating the noise generated by the expansion of gases into the atmosphere
US4077790A (en) * 1977-05-27 1978-03-07 Owens-Corning Fiberglas Corporation Noise suppressor for a row of rotary fiberizers
US5162620A (en) * 1989-11-28 1992-11-10 Allied-Signal Inc. Dual flow turbine engine muffler
US5203052A (en) * 1991-06-17 1993-04-20 Phoenix Associates Noise suppression box for fiber processing machinery
US5902970A (en) * 1995-07-17 1999-05-11 Ferri; Alain Muffler for internal combustion engines, especially in aviation of improved geometry and material
US5974802A (en) * 1997-01-27 1999-11-02 Alliedsignal Inc. Exhaust gas recirculation system employing a fluidic pump
US6182440B1 (en) 1986-01-14 2001-02-06 Northrop Grumman Corporation Infrared radiation coanda suppressor
US6240911B1 (en) * 1998-06-12 2001-06-05 Competition Cams, Inc. Air amplifier for nitrous oxide injection application
US6571910B2 (en) 2000-12-20 2003-06-03 Quiet Storm, Llc Method and apparatus for improved noise attenuation in a dissipative internal combustion engine exhaust muffler
US20070292811A1 (en) * 2006-06-14 2007-12-20 Poe Roger L Coanda gas burner apparatus and methods
US7354029B1 (en) * 2004-05-28 2008-04-08 Alex Rutstein Apparatus and method for treating process fluids
US20090057056A1 (en) * 2007-08-31 2009-03-05 Fred Baumgartner Vehicular exhaust resonator with cooling feature
US20110203128A1 (en) * 2008-10-23 2011-08-25 Oscar Jose Rodrigues Electrical Hair Dryer With Noise Reducer And Noise Reducer
US8006961B1 (en) * 2007-05-30 2011-08-30 Alex Rutstein Apparatus and method for treating process fluid
US20120149210A1 (en) * 2010-07-30 2012-06-14 Colvin Ronald L Systems, apparatuses, and methods for chemically processing substrates using the coanda effect
US20140034039A1 (en) * 2012-08-03 2014-02-06 Yiwei Qi Air exchange system with multiple air blowers or fans to produce a cyclone-like air flow
US20140174094A1 (en) * 2012-12-21 2014-06-26 United Technologies Corporation APU Exhaust Housing Perforated Ring
CN104061612A (zh) * 2014-07-16 2014-09-24 侯春景 一种抽油烟方法以及利用该方法制作的抽油烟机
US10207812B2 (en) 2015-09-02 2019-02-19 Jetoptera, Inc. Fluidic propulsive system and thrust and lift generator for aerial vehicles
CN109723684A (zh) * 2018-12-28 2019-05-07 浙江温兄机械阀业有限公司 一种蒸汽喷射低噪音热压泵
US10464668B2 (en) 2015-09-02 2019-11-05 Jetoptera, Inc. Configuration for vertical take-off and landing system for aerial vehicles
USD868627S1 (en) 2018-04-27 2019-12-03 Jetoptera, Inc. Flying car
WO2020051623A1 (fr) * 2018-09-13 2020-03-19 The University Of Adelaide Ensemble pour gaz d'échappement
DE102014100760B4 (de) * 2013-01-24 2020-08-20 Welipa Ag Abgasrohrschalldämpfer für BHKWs sowie Blockheizkraftanlage
US20200378597A1 (en) * 2016-06-03 2020-12-03 BSH Hausgeräte GmbH Gas burner and domestic cooking appliance

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RO62594A2 (fr) * 1975-06-12 1975-08-01 Inst Pentru Creatie Stintific Procede et dispositif pour l'attenuation du bruit de jet de gaz
GB2233037B (en) * 1988-11-26 1993-08-11 James David Coleman Combustion engines
GB2252128A (en) * 1991-01-24 1992-07-29 S & C Thermofluids Ltd Providing intercooler air coolant flow in turbocharged engines.
CN106246611B (zh) * 2016-08-01 2018-06-29 西南大学 一种适合低温条件下使用的空气放大器
JP7306899B2 (ja) * 2019-07-11 2023-07-11 株式会社日立製作所 付着物取集装置及び付着物分析システム
FR3127029A1 (fr) 2021-09-14 2023-03-17 Psa Automobiles Sa Procede de commande de demarrage automatique d’un moteur thermique comportant une priorisation de l’alimentation electrique des systemes

Citations (5)

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GB610841A (en) * 1946-01-21 1948-10-21 Likuvag A G Improvements in or relating to sound damping and silencing devices for gaseous currents
GB811612A (en) * 1956-07-27 1959-04-08 Sulzer Ag Rotary compressors
US3027714A (en) * 1959-06-11 1962-04-03 Canadair Ltd Combined thrust reversing and noise suppressing device for turbo-jet engines
US3349868A (en) * 1963-11-08 1967-10-31 Gruenzweig & Hartmann Sound suppressors particularly for jet engines
US3386528A (en) * 1964-01-04 1968-06-04 Gruenzweig & Hartmann Jet engine sound suppressor with coanda effect deflector

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB610841A (en) * 1946-01-21 1948-10-21 Likuvag A G Improvements in or relating to sound damping and silencing devices for gaseous currents
GB811612A (en) * 1956-07-27 1959-04-08 Sulzer Ag Rotary compressors
US3027714A (en) * 1959-06-11 1962-04-03 Canadair Ltd Combined thrust reversing and noise suppressing device for turbo-jet engines
US3349868A (en) * 1963-11-08 1967-10-31 Gruenzweig & Hartmann Sound suppressors particularly for jet engines
US3386528A (en) * 1964-01-04 1968-06-04 Gruenzweig & Hartmann Jet engine sound suppressor with coanda effect deflector

Cited By (34)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3794137A (en) * 1971-12-13 1974-02-26 Inst Pentru Creatie Stintific Device for attenuating the noise generated by the expansion of gases into the atmosphere
US4077790A (en) * 1977-05-27 1978-03-07 Owens-Corning Fiberglas Corporation Noise suppressor for a row of rotary fiberizers
US6182440B1 (en) 1986-01-14 2001-02-06 Northrop Grumman Corporation Infrared radiation coanda suppressor
US5162620A (en) * 1989-11-28 1992-11-10 Allied-Signal Inc. Dual flow turbine engine muffler
US5203052A (en) * 1991-06-17 1993-04-20 Phoenix Associates Noise suppression box for fiber processing machinery
US5902970A (en) * 1995-07-17 1999-05-11 Ferri; Alain Muffler for internal combustion engines, especially in aviation of improved geometry and material
US5974802A (en) * 1997-01-27 1999-11-02 Alliedsignal Inc. Exhaust gas recirculation system employing a fluidic pump
US6240911B1 (en) * 1998-06-12 2001-06-05 Competition Cams, Inc. Air amplifier for nitrous oxide injection application
US6571910B2 (en) 2000-12-20 2003-06-03 Quiet Storm, Llc Method and apparatus for improved noise attenuation in a dissipative internal combustion engine exhaust muffler
US7354029B1 (en) * 2004-05-28 2008-04-08 Alex Rutstein Apparatus and method for treating process fluids
US20070292811A1 (en) * 2006-06-14 2007-12-20 Poe Roger L Coanda gas burner apparatus and methods
US8568134B2 (en) 2006-06-14 2013-10-29 John Zink Company, Llc Coanda gas burner apparatus and methods
US8529247B2 (en) 2006-06-14 2013-09-10 John Zink Company, Llc Coanda gas burner apparatus and methods
US7878798B2 (en) 2006-06-14 2011-02-01 John Zink Company, Llc Coanda gas burner apparatus and methods
US20110117506A1 (en) * 2006-06-14 2011-05-19 John Zink Company, Llc Coanda Gas Burner Apparatus and Methods
US8337197B2 (en) 2006-06-14 2012-12-25 John Zink Company, Llc Coanda gas burner apparatus and methods
US8006961B1 (en) * 2007-05-30 2011-08-30 Alex Rutstein Apparatus and method for treating process fluid
US7845465B2 (en) * 2007-08-31 2010-12-07 Tenneco Automotive Operating Company Inc. Vehicular exhaust resonator with cooling feature
US20090057056A1 (en) * 2007-08-31 2009-03-05 Fred Baumgartner Vehicular exhaust resonator with cooling feature
US20110203128A1 (en) * 2008-10-23 2011-08-25 Oscar Jose Rodrigues Electrical Hair Dryer With Noise Reducer And Noise Reducer
US20120149210A1 (en) * 2010-07-30 2012-06-14 Colvin Ronald L Systems, apparatuses, and methods for chemically processing substrates using the coanda effect
US20140034039A1 (en) * 2012-08-03 2014-02-06 Yiwei Qi Air exchange system with multiple air blowers or fans to produce a cyclone-like air flow
US20140174094A1 (en) * 2012-12-21 2014-06-26 United Technologies Corporation APU Exhaust Housing Perforated Ring
DE102014100760B4 (de) * 2013-01-24 2020-08-20 Welipa Ag Abgasrohrschalldämpfer für BHKWs sowie Blockheizkraftanlage
CN104061612A (zh) * 2014-07-16 2014-09-24 侯春景 一种抽油烟方法以及利用该方法制作的抽油烟机
US10207812B2 (en) 2015-09-02 2019-02-19 Jetoptera, Inc. Fluidic propulsive system and thrust and lift generator for aerial vehicles
US10464668B2 (en) 2015-09-02 2019-11-05 Jetoptera, Inc. Configuration for vertical take-off and landing system for aerial vehicles
US10800538B2 (en) 2015-09-02 2020-10-13 Jetoptera, Inc. Ejector and airfoil configurations
US20200378597A1 (en) * 2016-06-03 2020-12-03 BSH Hausgeräte GmbH Gas burner and domestic cooking appliance
US11543122B2 (en) * 2016-06-03 2023-01-03 BSH Hausgeräte GmbH Gas burner and domestic cooking appliance
USD868627S1 (en) 2018-04-27 2019-12-03 Jetoptera, Inc. Flying car
WO2020051623A1 (fr) * 2018-09-13 2020-03-19 The University Of Adelaide Ensemble pour gaz d'échappement
JP2022500594A (ja) * 2018-09-13 2022-01-04 ジ ユニヴァーシティ オブ アデレードThe University of Adelaide 排気アセンブリ
CN109723684A (zh) * 2018-12-28 2019-05-07 浙江温兄机械阀业有限公司 一种蒸汽喷射低噪音热压泵

Also Published As

Publication number Publication date
RO53910A2 (fr) 1973-09-20
DE2126654C3 (de) 1974-06-20
FR2109611A5 (fr) 1972-05-26
GB1349194A (en) 1974-03-27
DE2126654B2 (de) 1973-11-22
DE2126654A1 (de) 1972-05-31
HU166109B (fr) 1975-01-28
CS150921B2 (fr) 1973-09-17

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