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WO1995019075A3 - Active muffler - Google Patents

Active muffler Download PDF

Info

Publication number
WO1995019075A3
WO1995019075A3 PCT/US1994/014956 US9414956W WO9519075A3 WO 1995019075 A3 WO1995019075 A3 WO 1995019075A3 US 9414956 W US9414956 W US 9414956W WO 9519075 A3 WO9519075 A3 WO 9519075A3
Authority
WO
WIPO (PCT)
Prior art keywords
flow
duct
acoustic
porous
porous member
Prior art date
Application number
PCT/US1994/014956
Other languages
French (fr)
Other versions
WO1995019075A2 (en
Inventor
Istvan L Ver
Original Assignee
Bolt Beranek & Newman
Istvan L Ver
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 Bolt Beranek & Newman, Istvan L Ver filed Critical Bolt Beranek & Newman
Priority to AU19079/95A priority Critical patent/AU1907995A/en
Publication of WO1995019075A2 publication Critical patent/WO1995019075A2/en
Publication of WO1995019075A3 publication Critical patent/WO1995019075A3/en
Priority to US08/850,036 priority patent/US6160892A/en

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02K—JET-PROPULSION PLANTS
    • F02K1/00—Plants characterised by the form or arrangement of the jet pipe or nozzle; Jet pipes or nozzles peculiar thereto
    • F02K1/44—Nozzles having means, e.g. a shield, reducing sound radiation in a specified direction
    • 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
    • G10K11/17879—General system configurations using both a reference signal and an error signal
    • G10K11/17881—General system configurations using both a reference signal and an error signal the reference signal being an acoustic signal, e.g. recorded with a microphone
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
    • F05D2260/00—Function
    • F05D2260/96—Preventing, counteracting or reducing vibration or noise
    • F05D2260/962—Preventing, counteracting or reducing vibration or noise by means of "anti-noise"
    • 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
    • G10K2210/108—Communication systems, e.g. where useful sound is kept and noise is cancelled
    • G10K2210/1082—Microphones, e.g. systems using "virtual" 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
    • 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
    • G10K2210/1281—Aircraft, e.g. spacecraft, airplane or helicopter
    • 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
    • G10K2210/30—Means
    • G10K2210/321—Physical
    • G10K2210/3217—Collocated sensor and cancelling actuator, e.g. "virtual earth" designs
    • 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)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Exhaust Silencers (AREA)
  • Soundproofing, Sound Blocking, And Sound Damping (AREA)

Abstract

In the active muffler disclosed herein, a porous flow resistive member (19) defines a wall of a duct carrying a noisy flow, e.g., a jet exhaust. The flow resistive member (19) is characterized by having a flow resistance substantially less than ςC, the characteristic impedance of the acoustic medium. Loudspeakers (45) in a chamber on the side of said porous member (25) opposite the duct are actuated to reduce acoustic pressure in the region between the porous member and the loudspeaker, thereby increasing the acoustic flow through the porous member (25) which in turn increases the dissipation of acoustic energy in the duct. The apparatus is particularly effective at low frequencies where a passive dissipative muffler would be of impractical size.
PCT/US1994/014956 1993-12-30 1994-12-28 Active muffler WO1995019075A2 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
AU19079/95A AU1907995A (en) 1993-12-30 1994-12-28 Active muffler
US08/850,036 US6160892A (en) 1993-12-30 1997-05-02 Active muffler

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US17610293A 1993-12-30 1993-12-30
US08/176,102 1993-12-30

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
US17610293A Continuation-In-Part 1993-12-30 1993-12-30

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US66539196A Continuation 1993-12-30 1996-06-18

Publications (2)

Publication Number Publication Date
WO1995019075A2 WO1995019075A2 (en) 1995-07-13
WO1995019075A3 true WO1995019075A3 (en) 1995-07-27

Family

ID=22642986

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US1994/014956 WO1995019075A2 (en) 1993-12-30 1994-12-28 Active muffler

Country Status (2)

Country Link
AU (1) AU1907995A (en)
WO (1) WO1995019075A2 (en)

Families Citing this family (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5606622A (en) * 1994-09-29 1997-02-25 The Boeing Company Active noise control in a duct with highly turbulent airflow
FR2740599B1 (en) * 1995-10-30 1997-12-19 Technofirst ACTIVE ACOUSTIC MITIGATION DEVICE INTENDED TO BE ARRANGED WITHIN A DUCT, PARTICULARLY FOR SOUNDPROOFING A VENTILATION AND / OR AIR CONDITIONING NETWORK
JP3510427B2 (en) * 1996-08-15 2004-03-29 三菱重工業株式会社 Active sound absorbing wall
US5848168A (en) * 1996-11-04 1998-12-08 Tenneco Automotive Inc. Active noise conditioning system
MY125833A (en) * 1997-06-06 2006-08-30 Carrier Corp Wall cavity microphone turbulence shield
SE0003350D0 (en) * 2000-09-18 2000-09-18 Flaekt Ab Silencer
SE0003348D0 (en) * 2000-09-18 2000-09-18 Flaekt Ab Apparatus and method for measuring the flow in a fluid
CN101871473B (en) * 2010-06-09 2012-03-07 中国矿业大学 Impedance composite muffler
BE1024535B1 (en) 2016-09-05 2018-04-04 Safran Aero Boosters S.A. TURBOMACHINE TEST BENCH WITH ACTIVE NOISE CONTROL
FR3104860B1 (en) * 2019-12-16 2024-05-17 Centre Nat Rech Scient METHOD AND DEVICE FOR CONTROLLING THE PROPAGATION OF ACOUSTIC WAVES ON A WALL

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0483921A1 (en) * 1990-10-31 1992-05-06 Matsushita Electric Works, Ltd. Acoustic conductance in a system of duct

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0483921A1 (en) * 1990-10-31 1992-05-06 Matsushita Electric Works, Ltd. Acoustic conductance in a system of duct

Also Published As

Publication number Publication date
WO1995019075A2 (en) 1995-07-13
AU1907995A (en) 1995-08-01

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