GB1357330A - Dynamic silencing systems - Google Patents

Dynamic silencing systems

Info

Publication number
GB1357330A
GB1357330A GB3179570A GB3179570A GB1357330A GB 1357330 A GB1357330 A GB 1357330A GB 3179570 A GB3179570 A GB 3179570A GB 3179570 A GB3179570 A GB 3179570A GB 1357330 A GB1357330 A GB 1357330A
Authority
GB
United Kingdom
Prior art keywords
sound
aperture
source
fork
amplifier
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
GB3179570A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
UK Secretary of State for Defence
Original Assignee
UK Secretary of State for Defence
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by UK Secretary of State for Defence filed Critical UK Secretary of State for Defence
Priority to GB3179570A priority Critical patent/GB1357330A/en
Publication of GB1357330A publication Critical patent/GB1357330A/en
Expired legal-status Critical Current

Links

Classifications

    • 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
    • F16L55/0333—Noise absorbers by means of an active system
    • 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
    • G10K11/175—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound
    • G10K11/178—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound by electro-acoustically regenerating the original acoustic waves in anti-phase
    • G10K11/1781—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound by electro-acoustically regenerating the original acoustic waves in anti-phase characterised by the analysis of input or output signals, e.g. frequency range, modes, transfer functions
    • G10K11/17821—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound by electro-acoustically regenerating the original acoustic waves in anti-phase characterised by the analysis of input or output signals, e.g. frequency range, modes, transfer functions characterised by the analysis of the input signals only
    • G10K11/17823—Reference signals, e.g. ambient acoustic environment
    • 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
    • G10K11/175—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound
    • G10K11/178—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound by electro-acoustically regenerating the original acoustic waves in anti-phase
    • G10K11/1785—Methods, e.g. algorithms; Devices
    • G10K11/17857—Geometric disposition, e.g. placement of microphones
    • 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
    • G10K11/175—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound
    • G10K11/178—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound by electro-acoustically regenerating the original acoustic waves in anti-phase
    • G10K11/1785—Methods, e.g. algorithms; Devices
    • G10K11/17861—Methods, e.g. algorithms; Devices using additional means for damping sound, e.g. using sound absorbing panels
    • 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
    • G10K11/175—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound
    • G10K11/178—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound by electro-acoustically regenerating the original acoustic waves in anti-phase
    • G10K11/1787—General system configurations
    • G10K11/17873—General system configurations using a reference signal without an error signal, e.g. pure feedforward
    • 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
    • G10K2210/00—Details of active noise control [ANC] covered by G10K11/178 but not provided for in any of its subgroups
    • G10K2210/10—Applications
    • G10K2210/112—Ducts
    • 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
    • G10K2210/00—Details of active noise control [ANC] covered by G10K11/178 but not provided for in any of its subgroups
    • G10K2210/10—Applications
    • G10K2210/128—Vehicles
    • G10K2210/1282—Automobiles
    • G10K2210/12822—Exhaust pipes or mufflers
    • 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
    • G10K2210/00—Details of active noise control [ANC] covered by G10K11/178 but not provided for in any of its subgroups
    • G10K2210/30—Means
    • G10K2210/321—Physical
    • G10K2210/3214—Architectures, e.g. special constructional features or arrangements of features
    • 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
    • G10K2210/00—Details of active noise control [ANC] covered by G10K11/178 but not provided for in any of its subgroups
    • G10K2210/50—Miscellaneous
    • G10K2210/509—Hybrid, i.e. combining different technologies, e.g. passive and active

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Acoustics & Sound (AREA)
  • Multimedia (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Soundproofing, Sound Blocking, And Sound Damping (AREA)
  • Exhaust Silencers (AREA)
  • Fittings On The Vehicle Exterior For Carrying Loads, And Devices For Holding Or Mounting Articles (AREA)

Abstract

1357330 Noise reduction DEFENCE SECRETARY OF STATE FOR 15 July 1971 [1 July 1970] 31795/70 Heading H4J Reduction of sound having one or more prominent frequencies, produced by a source in an enclosure and emitted through an aperture is obtained by picking up a sample of the sound, amplifying the sample and directing the amplified sample sound so that it interferes destructivey with sound from the source in the region of the aperture. Preferably the phase difference between the sound emitted by the source and the amplified sound is between 177 degrees and 183 degrees at the aperture. The sound source may be a generating set, compressor, motor boat engine, hydraulic or pneumatic equipment or a power unit on a fighting vehicle. In a first embodiment an internal combustion engine 2 is situated in a first fork 4 in a duct 20. The sound is picked up by a unidirectional microphone 8 and corresponding electrical signals are passed through an amplifier 12 and phase shifter 14 to a loud-speaker 16 in a second fork 18 of the duct 20. A sound level meter 24 in the aperture 22 of duct 20 is used to adjust the amplifier 12 and phase shifter 14 until minimum noise level is registered. Instead of reducing noise at aperture 22, the noise at aperture 28 may be reduced. Frequencies above 1 KHz may be absorbed by a lining 26 of mineral wool. Preferably the adjustments are made to provide 180 degrees phase shift at the fundamental frequency of the sound source. If a number of frequencies are strongly represented an amplifier, phase shifter and loud-speaker may deal with each frequency separately. An alternative duct 30 (Fig. 2) has two forks 32, 34 and an aperture 35. Fork 32 is connected to a housing (not shown) for an internal combustion engine. A condenser microphone 38 in a chamber 42 through which flows cooling water 44 is set in the wall of the fork. It is connected to an amplifier and phase shifter 40 the output of which is applied to a loud-speaker 46 whose rear is sealed by an enclosure 48. Destructive interference ensures that little sound is emitted from the aperture 35.
GB3179570A 1970-07-01 1970-07-01 Dynamic silencing systems Expired GB1357330A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB3179570A GB1357330A (en) 1970-07-01 1970-07-01 Dynamic silencing systems

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB3179570A GB1357330A (en) 1970-07-01 1970-07-01 Dynamic silencing systems

Publications (1)

Publication Number Publication Date
GB1357330A true GB1357330A (en) 1974-06-19

Family

ID=10328529

Family Applications (1)

Application Number Title Priority Date Filing Date
GB3179570A Expired GB1357330A (en) 1970-07-01 1970-07-01 Dynamic silencing systems

Country Status (1)

Country Link
GB (1) GB1357330A (en)

Cited By (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4044203A (en) * 1972-11-24 1977-08-23 National Research Development Corporation Active control of sound waves
FR2386881A1 (en) * 1977-04-05 1978-11-03 Sound Attenuators Ltd Active sound attenuation using secondary wave - has stored programme used to obtain signal representing secondary wave
WO1981001479A1 (en) * 1979-11-10 1981-05-28 Sound Attenuators Ltd The cancelling of vibrations transmitted through a fluid in a containing vessel
EP0040462A1 (en) * 1980-05-16 1981-11-25 Bose Corporation Electroacoustical audible noise reducing apparatus
FR2495809A1 (en) * 1980-12-05 1982-06-11 Lord Corp APPARATUS FOR MITIGATING SOUND VIBRATIONS AND VIBRATION SUPPRESSION
US4637048A (en) * 1984-03-07 1987-01-13 National Research Development Corp. Methods and apparatus for reducing noise by cancellation
GB2177238A (en) * 1985-06-29 1987-01-14 Voith Gmbh J M Control apparatus for damping vibrations
GB2204916A (en) * 1987-05-19 1988-11-23 British Gas Plc Gaseous flow silencer
US5325438A (en) * 1993-02-01 1994-06-28 At&T Bell Laboratories Active noise-cancellation system for automotive mufflers
US5457750A (en) * 1990-12-19 1995-10-10 Gold Star Company, Ltd. Method and device for reducing noises generated at an indoor unit of a separate type room air conditioner package
US5541373A (en) * 1994-09-06 1996-07-30 Digisonix, Inc. Active exhaust silencer
US5693918A (en) * 1994-09-06 1997-12-02 Digisonix, Inc. Active exhaust silencer
EP0840285A2 (en) * 1996-11-04 1998-05-06 Tenneco Automotive Inc. Active noise conditioning system
EP2623737A1 (en) * 2012-02-06 2013-08-07 Eberspächer Exhaust Technology GmbH & Co. KG Active silencer
DE102012212843A1 (en) * 2012-07-23 2014-01-23 Behr Gmbh & Co. Kg air conditioning
CN116085572A (en) * 2021-01-14 2023-05-09 哈尔滨工程大学 Electroacoustic coupling-based pipeline low-frequency noise control device

Cited By (24)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4044203A (en) * 1972-11-24 1977-08-23 National Research Development Corporation Active control of sound waves
FR2386881A1 (en) * 1977-04-05 1978-11-03 Sound Attenuators Ltd Active sound attenuation using secondary wave - has stored programme used to obtain signal representing secondary wave
WO1981001479A1 (en) * 1979-11-10 1981-05-28 Sound Attenuators Ltd The cancelling of vibrations transmitted through a fluid in a containing vessel
EP0040462A1 (en) * 1980-05-16 1981-11-25 Bose Corporation Electroacoustical audible noise reducing apparatus
FR2495809A1 (en) * 1980-12-05 1982-06-11 Lord Corp APPARATUS FOR MITIGATING SOUND VIBRATIONS AND VIBRATION SUPPRESSION
US4473906A (en) * 1980-12-05 1984-09-25 Lord Corporation Active acoustic attenuator
US4637048A (en) * 1984-03-07 1987-01-13 National Research Development Corp. Methods and apparatus for reducing noise by cancellation
GB2177238A (en) * 1985-06-29 1987-01-14 Voith Gmbh J M Control apparatus for damping vibrations
GB2177238B (en) * 1985-06-29 1989-07-19 Voith Gmbh J M A preparation system for fibrous stock suspensions having control apparatus for damping vibrations
GB2204916A (en) * 1987-05-19 1988-11-23 British Gas Plc Gaseous flow silencer
GB2204916B (en) * 1987-05-19 1991-10-16 British Gas Plc A silencer
US5457750A (en) * 1990-12-19 1995-10-10 Gold Star Company, Ltd. Method and device for reducing noises generated at an indoor unit of a separate type room air conditioner package
WO1994017761A1 (en) * 1993-02-01 1994-08-18 At & T Corp. Active noise-cancellation system for automotive mufflers
US5325438A (en) * 1993-02-01 1994-06-28 At&T Bell Laboratories Active noise-cancellation system for automotive mufflers
US5541373A (en) * 1994-09-06 1996-07-30 Digisonix, Inc. Active exhaust silencer
US5693918A (en) * 1994-09-06 1997-12-02 Digisonix, Inc. Active exhaust silencer
EP0840285A2 (en) * 1996-11-04 1998-05-06 Tenneco Automotive Inc. Active noise conditioning system
US5848168A (en) * 1996-11-04 1998-12-08 Tenneco Automotive Inc. Active noise conditioning system
EP0840285A3 (en) * 1996-11-04 1999-05-12 Tenneco Automotive Inc. Active noise conditioning system
EP2623737A1 (en) * 2012-02-06 2013-08-07 Eberspächer Exhaust Technology GmbH & Co. KG Active silencer
US20130202148A1 (en) * 2012-02-06 2013-08-08 Eberspächer Exhaust Technology GmbH & Co. KG Active muffler
DE102012212843A1 (en) * 2012-07-23 2014-01-23 Behr Gmbh & Co. Kg air conditioning
US9396718B2 (en) 2012-07-23 2016-07-19 Mahle International Gmbh Air conditioning unit
CN116085572A (en) * 2021-01-14 2023-05-09 哈尔滨工程大学 Electroacoustic coupling-based pipeline low-frequency noise control device

Similar Documents

Publication Publication Date Title
GB1357330A (en) Dynamic silencing systems
US4805733A (en) Active silencer
US3936606A (en) Acoustic abatement method and apparatus
US5119427A (en) Extended frequency range Helmholtz resonators
GB2240199A (en) Low noise refrigerator
CA2038440A1 (en) Active muffler transducer arrangement
US4109108A (en) Attenuation of sound waves in ducts
US2441030A (en) Arrangement for producing a triggering effect in proximity to an object adapted to radiate radiantwave energy
GB2245452A (en) Active noise attenuation
US3125953A (en) Amplifier
JP3301465B2 (en) Speaker device and silencer using the same
GB985051A (en) Improvements in or relating to sound attenuating gas conduit
EP0040462A1 (en) Electroacoustical audible noise reducing apparatus
GB1342799A (en) Method of and device for enhancing marine navigational sound signals in the presence of acoustic noise
JPH0639896B2 (en) Active silencer
JPH02225971A (en) Noise suppressor for cooling device
JPH03231599A (en) Active control type silencer
JPH08106293A (en) Active noise elimination system
JPH0694349A (en) Sound muffling device in cooling device
JP2721051B2 (en) Engine noise reduction device
JPH02225985A (en) Noise suppressor for cooling device
JP3003329B2 (en) Silencer
JP2624858B2 (en) refrigerator
JPH1165574A (en) Silencing device
JPS62206212A (en) Active silencer

Legal Events

Date Code Title Description
PS Patent sealed
PCNP Patent ceased through non-payment of renewal fee