Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
  • F02M35/00—Combustion-air cleaners, air intakes, intake silencers, or induction systems specially adapted for, or arranged on, internal-combustion engines
  • F02M35/10—Air intakes; Induction systems
  • F02M35/10242—Devices or means connected to or integrated into air intakes; Air intakes combined with other engine or vehicle parts
  • F02M35/10295—Damping means, e.g. tranquillising chamber to dampen air oscillations
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
  • F02M35/00—Combustion-air cleaners, air intakes, intake silencers, or induction systems specially adapted for, or arranged on, internal-combustion engines
  • F02M35/12—Intake silencers ; Sound modulation, transmission or amplification
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
  • F02M35/00—Combustion-air cleaners, air intakes, intake silencers, or induction systems specially adapted for, or arranged on, internal-combustion engines
  • F02M35/10—Air intakes; Induction systems
  • F02M35/10006—Air intakes; Induction systems characterised by the position of elements of the air intake system in direction of the air intake flow, i.e. between ambient air inlet and supply to the combustion chamber
  • F02M35/10019—Means upstream of the fuel injection system, carburettor or plenum chamber
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
  • F02M35/00—Combustion-air cleaners, air intakes, intake silencers, or induction systems specially adapted for, or arranged on, internal-combustion engines
  • F02M35/10—Air intakes; Induction systems
  • F02M35/10091—Air intakes; Induction systems characterised by details of intake ducts: shapes; connections; arrangements
  • F02M35/10111—Substantially V-, C- or U-shaped ducts in direction of the flow path
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
  • F02M35/00—Combustion-air cleaners, air intakes, intake silencers, or induction systems specially adapted for, or arranged on, internal-combustion engines
  • F02M35/10—Air intakes; Induction systems
  • F02M35/10242—Devices or means connected to or integrated into air intakes; Air intakes combined with other engine or vehicle parts
  • F02M35/10262—Flow guides, obstructions, deflectors or the like
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
  • F02M35/00—Combustion-air cleaners, air intakes, intake silencers, or induction systems specially adapted for, or arranged on, internal-combustion engines
  • F02M35/12—Intake silencers ; Sound modulation, transmission or amplification
  • F02M35/1205—Flow throttling or guiding
  • F02M35/1211—Flow throttling or guiding by using inserts in the air intake flow path, e.g. baffles, throttles or orifices; Flow guides
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
  • F02M35/00—Combustion-air cleaners, air intakes, intake silencers, or induction systems specially adapted for, or arranged on, internal-combustion engines
  • F02M35/12—Intake silencers ; Sound modulation, transmission or amplification
  • F02M35/1205—Flow throttling or guiding
  • F02M35/1216—Flow throttling or guiding by using a plurality of holes, slits, protrusions, perforations, ribs or the like; Surface structures; Turbulence generators
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
  • F02M35/00—Combustion-air cleaners, air intakes, intake silencers, or induction systems specially adapted for, or arranged on, internal-combustion engines
  • F02M35/12—Intake silencers ; Sound modulation, transmission or amplification
  • F02M35/1205—Flow throttling or guiding
  • F02M35/1227—Flow throttling or guiding by using multiple air intake flow paths, e.g. bypass, honeycomb or pipes opening into an expansion chamber
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
  • F16L55/00—Devices or appurtenances for use in, or in connection with, pipes or pipe systems
  • F16L55/02—Energy absorbers; Noise absorbers
  • F16L55/033—Noise absorbers
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
  • F16L55/00—Devices or appurtenances for use in, or in connection with, pipes or pipe systems
  • F16L55/02—Energy absorbers; Noise absorbers
  • F16L55/033—Noise absorbers
  • F16L55/0331—Noise absorbers by inserting an elongated element in the pipe
• • G—PHYSICS
  • G10—MUSICAL INSTRUMENTS; ACOUSTICS
  • G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
  • G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
  • G10K11/16—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
  • G10K11/172—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using resonance effects
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
  • F02B29/00—Engines characterised by provision for charging or scavenging not provided for in groups F02B25/00, F02B27/00 or F02B33/00 - F02B39/00; Details thereof
  • F02B29/04—Cooling of air intake supply
  • F02B29/0406—Layout of the intake air cooling or coolant circuit
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
  • F02B37/00—Engines characterised by provision of pumps driven at least for part of the time by exhaust
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
  • Y02T10/00—Road transport of goods or passengers
  • Y02T10/10—Internal combustion engine [ICE] based vehicles
  • Y02T10/12—Improving ICE efficiencies

Definitions

• the present invention relates to a device for damping of sound in a pipe according to the preamble of claim 1.
• turbo howl The strength of the sound which occurs when air is drawn into the compressor of the turbo unit, i.e. the so-called turbo howl, has therefore also increased.
• This sound is of high frequency typically between 5 and 15 kHz.
• GB 1 339 526 refers to a sound damper in an exhaust line of a gas turbine.
• the sound damper comprises a plurality of guide elements arranged in parallel which divide the exhaust line into parallel flow channels close to a curved portion of the exhaust line.
• the guide elements comprise sound-absorbing material. The sound-absorbing material results in the guide elements being relatively wide and space-occupying. To prevent the exhaust gases undergoing too great a pressure drop as they pass between the guide elements, the exhaust line portion has been widened in this region.
• US 5,709,529 refers to a sound damper arranged in a curved pipe portion for supply of air to a turbo machine.
• the sound damper comprises a plurality of thin guide elements which lead the air into alternative flow channels in the curved pipe portion.
• the guide elements are of different lengths so that the sound emanating from the various flow channels has a definite mutual phase shift so that the sounds at least partly cancel one another out.
• the object of the present invention is to provide a device which results in simple but effective damping of sound in a pipe through which a gaseous medium flows, without the flow of the gaseous medium being substantially affected.
• the sound which occurs in the pipe may be defined as pressure fluctuations of the gaseous medium inside the pipe.
• the sound propagates substantially uniformly in all directions inside the pipe.
• the sound which reaches the surface of the guide element will thus be partly reflected and undergo a certain absorption.
• Some of the sound, however, will pass through the holes in the guide element together with the gaseous medium. As the holes are relatively narrow, the sonic energy is effectively reduced as the sound passes through the holes, resulting in damping of the sound.
• the guide element is arranged in a curved pipe portion. Dividing a curved pipe portion into flow channels considerably hinders sound propagation through the curved pipe portion. The sound will be reflected by the guide element and the wall surface of the curved pipe portion. The result is absorption of the sound and relatively good damping.
• the guide element and the curved pipe portion have curvature of such magnitude that sound cannot pass through said flow channels without encountering at least one wall surface of the guide element or the curved pipe portion. All of the sound will thus be reflected by at least one surface and/or be pushed through one of said holes in the guide element. Thus none of the sound can pass totally undamped through the curved pipe portion.
• the guide element is preferably of a curved shape with a centre of curvature substantially corresponding to that of the curved pipe portion.
• the guide element can therefore divide the curved pipe portion into flow channels of substantially the same size with a substantially constant cross-sectional area along the whole of their extent. The result is a more uniform flow through the curved pipe portion.
• the thickness of the guide element is within the range 0.5 to 5 mm.
• a guide element made of, for example, sheetmetal can be made so thin that it substantially does not reduce the cross- sectional area for the gaseous medium passing through said pipe portion. In such cases the thickness of the guide element may be in the lower part of the range indicated above, i.e. about 1 mm.
• the guide element is made of a metal material.
• the guide element may be made from a sheet of metal provided with holes running through it. Such a sheet may be of aluminium. If instead the guide element takes for example the form of a wing section, it will be thicker and may then be up to 5 mm thick.
• the device comprises at least one flow channel defined by a surface of the guide element and an opposite surface of the guide element, whereby said surfaces are situated at a predetermined distance from one another which corresponds to one-quarter of the wavelength of the sound primarily intended to be damped in the pipe.
• the frequency and wavelength of the sound which occurs in a pipe with a flowing gaseous medium are known.
• the device comprises at least two guide elements, whereby said guide elements comprise mutually opposite surfaces which define an intermediate flow channel and whereby said mutually opposite surfaces are situated at a predetermined distance from one another which corresponds to half the wavelength of the sound primarily intended to be damped in the pipe.
• a flow channel with such dimensioning provides further damping of sound at that wavelength.
• the magnitude of said holes is such that at least two substantially mutually opposite side edges of the holes are situated at a distance from one another of not more than 5 mm.
• the resistance to flow of air and sound through a hole is closely related to the narrowness of the hole. The narrower the hole, the greater the resistance to air and sound passing through it. With advantage, such a hole is made relatively elongate. The hole thus presents a relatively large cross-sectional area so that an ample amount of air can pass through the hole despite its relative narrowness.
• the guide element is arranged in a pipe portion situated substantially immediately upstream of a compressor in the direction of flow of the gaseous medium.
• a gaseous medium is drawn into a compressor, a disturbing sound usually occurs.
• the construction of the compressor is usually optimised to meet certain capacity requirements. In many cases it is therefore not advantageous to subject a compressor to internal modifications in order to reduce the occurrence of such disturbing sound. The occurrence of the disturbing sound is also affected by the flow pattern of the gaseous medium before the medium reaches the compressor. Against this background, it seems most advantageous to arrange the guide element in a curved pipe portion substantially immediately upstream of the compressor.
• the compressor may form part of a turbo unit for a combustion engine. In many cases, turbo units give rise to a strong high-frequency whistling sound which may be perceived as disturbing. In such cases, a suitable number of guide elements can with advantage be fitted in a curved pipe portion upstream of the compressor in order to damp this sound.
• Fig. 1 depicts an arrangement with a sound-damping device and a turbo unit for supplying compressed air to a supercharged diesel engine
• Fig. 2 depicts the sound-damping device in Fig. 1 in more detail
• Fig. 3 depicts a workpiece for making a guide element of the sound-damping device and Fig. 4 depicts an alternative workpiece for making a guide element of the sound- damping device.
• Fig. 1 depicts an arrangement with a turbo unit for supplying compressed air to a supercharged combustion engine.
• the combustion engine is here exemplified as a diesel engine 1.
• the diesel engine 1 may be intended for powering a heavy vehicle.
• the exhaust gases from the cylinders of the diesel engine 1 are led via an exhaust manifold 2 to at least one exhaust line 3.
• the exhaust gases in the exhaust line 3, which are at above atmospheric pressure, are led to a turbine 4 of a turbo unit.
• the turbine 4 is thus provided with driving power which is transmitted, via a connection, to a compressor 5 of the turbo unit.
• the compressor 5 thus compresses air which is led via an air filter 6 into an inlet line 7 to the diesel engine 1.
• a charge air cooler 8 is arranged in the inlet line 7 to cool the compressed air before it is led to the respective cylinders of the diesel engine 1 via a manifold 9.
• a high-frequency whistling sound usually called turbo howl occurs.
• the sound may be at a frequency of about 10 kHz.
• a schematically depicted sound-damping device 10 is fitted in a curved portion T of the inlet line.
• the curved pipe portion T is situated substantially immediately upstream of the compressor 5 with respect to the direction of air flow in the inlet line 7.
• Fig. 2 depicts the sound damping device 10 in more detail.
• the curvature of the curved pipe portion T is about 90 degrees.
• Three guide elements 1 Ia, b, c are fitted successively peripherally externally to one another in the curved pipe portion T.
• the guide elements 1 la-c each likewise have a curvature of about 90 degrees between an upstream end and a downstream end.
• the curved pipe portion T may with advantage have a substantially rectangular cross-sectional area to make it easier to shape and fit the guide elements 1 la-c.
• the curved pipe portion T may nevertheless have a cross-sectional area of substantially any desired shape.
• the guide elements 1 la-c are made of relatively thin sheetmetal which may be sheet aluminium.
• the thickness of the guide elements 1 la-c is within the range 0.5 to 1.5 mm.
• the guide elements 1 la-c are thus so thin as to reduce only negligibly the cross-sectional area for air flowing in the curved pipe portion 7'.
• the guide elements 1 la-c are nevertheless rigid enough to guide the air flowing in the pipe 7 without becoming deformed.
• the guide elements 1 la-c divide the internal space of the curved pipe portion T into four flow channels 12a-d which are successively situated radially externally to one another. Dividing the curved pipe portion T into such flow channels 12a-d reduces the variation in the velocity of the air flowing between different regions of the curved pipe portion T.
• the presence of the guide elements 1 la-c results in a more uniform flow of air to the compressor 5.
• the respective guide elements 11 a-c and the curved pipe portion T have a curved shape with a substantially common centre of curvature 13.
• Mutually adjacent guide elements 1 la-c can therefore be arranged at a substantially constant distance d 2 , d 3 from one another along their whole extent.
• the radially innermost and outermost guide elements 1 Ia, c are situated at substantially the same distance dj, d 4 from the adjacent surface of the curved pipe portion T along the whole of their respective extent.
• the radially innermost and outermost flow channels di, d 4 have in this case substantially half the width of the middle flow channels d 2 , d 3 in a radial direction throughout the curved pipe portion T.
• the guide elements 1 la-c are provided with a large number of holes 11 ' running through them. It is thus possible for the air flowing through the flow channels 12a-d to be led through the holes 11 ' into adjacent flow channels 12a-d.
• the air is led through the holes 11 ' when there are pressure differences on opposite sides of the holes 11'.
• the result is that air is led through the holes 11 ' towards the side which at the time has the lower pressure.
• the holes 11 ' are nevertheless narrow enough to create an appreciable resistance to the air being led through the holes 11'.
• Fig. 3 depicts a front view of a substantially rectangular metal sheet 14 before it is shaped to form a curved guide element 1 la-c.
• the metal sheet 14 is microslit so that it comprises a large number of holes 11 ' running through it.
• the holes 11 ' have an elongate shape which in this case is substantially rectangular. The shorter the short sides of the rectangular holes 1 V, the narrower the holes 11 ' and the greater the resistance which air has to overcome in order to flow through the holes 11'.
• the short sides may be of the order of magnitude of 0.1 mm.
• Fig. 4 depicts a front view of a rectangular metal net 15 before it is shaped to form a curved guide element 11.
• the metal net 15 comprises a large number of holes 11 ' running through it which in this case are substantially square in shape.
• the size of the holes 11 ' may be about 1 mm x 1 mm. The holes 11 ' are therefore so narrow that air is subject to an appreciable resistance as it is led through the holes 11'.
• each of the flow channels 12a-d is such that the sound from the compressor 5 cannot propagate through the curved pipe portion T without encountering the guide elements 1 la-c or the internal surfaces of the curved pipe portion 7'. Part of the sound is reflected by said surfaces, resulting in successive damping of the sound. Part of the sound which encounters the guide elements 1 la-c propagates through the holes 11 ' with a certain resistance. This sound undergoes a loss of energy and is therefore damped. Since the frequency range within which the disturbing sound occurs is known, it is also possible to adapt the radial width di-d 4 of the flow channels 12a-d so as to achieve substantially optimum damping of a specific sound.
• Effective damping of a specific sound is achieved when the radially innermost and outermost flow channels 12a, d have an extent dj, d_t in a radial direction in the curved pipe portion 7' which corresponds to one-quarter of the wavelength of the sound primarily intended to be damped in the pipe 7.
• the radial extent d l5 Cl 4 of the flow channels 12 can be determined.
• the radial extent di, d_i of the flow channels 12a, d will be 7 to 8 mm for maximum damping of sound at that frequency. The result is very effective damping of sound at that frequency.
• the middle flow channels 12b, c between mutually adjacent guide elements 1 Ia- c may be given a radial extent d 2 , d 3 corresponding to half the wavelength of said specific sound.
• the radial extent d 2 , d 3 of the flow channels 12b, c will be about 15 mm for maximum damping of sound at that frequency.
• the present device thus provides very effective damping of the sound from a turbo unit in a relatively simple manner and substantially without disturbing the pattern of air flow and without auxiliary means which would require more space.
• the invention is in no way limited to the embodiments described with reference to the drawings but may be varied freely within the scopes of the claims.
• the device is not limited to being used in an inlet line for air to a combustion engine but may be used in substantially any desired pipe through which a gaseous medium flows.
• the gaseous medium need not be air.
• the guide elements may be of substantially any desired but functional shape and substantially any desired number of them may be fitted inside the pipe and form flow channels of any desired width.

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• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Physics & Mathematics (AREA)
• Acoustics & Sound (AREA)
• Multimedia (AREA)
• Exhaust Silencers (AREA)
• Pipe Accessories (AREA)
• Soundproofing, Sound Blocking, And Sound Damping (AREA)

Applications Claiming Priority (2)

Publications (2)

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ID=37215014

Family Applications (1)

Country Status (6)

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Citations (5)

Family Cites Families (6)

• 2005
  • 2005-04-27 SE SE0500958A patent/SE528857C2/sv not_active IP Right Cessation
• 2006
  • 2006-04-26 BR BRPI0609953-0A patent/BRPI0609953A2/pt not_active IP Right Cessation
  • 2006-04-26 WO PCT/SE2006/050086 patent/WO2006115461A1/en active Application Filing
  • 2006-04-26 EP EP06733456.5A patent/EP1878009A4/de not_active Withdrawn
  • 2006-04-26 KR KR1020077027548A patent/KR101280597B1/ko not_active IP Right Cessation
  • 2006-04-26 AU AU2006240549A patent/AU2006240549B2/en not_active Ceased

Patent Citations (5)

Non-Patent Citations (1)

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