WO2004017301A1 - Vorrichtung und verfahren zur aktiven schallbekämpfung sowie triebwerk für flugzeuge - Google Patents
Vorrichtung und verfahren zur aktiven schallbekämpfung sowie triebwerk für flugzeuge Download PDFInfo
- Publication number
- WO2004017301A1 WO2004017301A1 PCT/DE2003/002292 DE0302292W WO2004017301A1 WO 2004017301 A1 WO2004017301 A1 WO 2004017301A1 DE 0302292 W DE0302292 W DE 0302292W WO 2004017301 A1 WO2004017301 A1 WO 2004017301A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- chamber
- gas stream
- gas
- deflection device
- sound
- Prior art date
Links
Classifications
-
- 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
Definitions
- the present invention relates to a device for active noise control according to the preamble of claim 1, the use of such a device in an engine, in particular an aircraft engine, a method for active noise control and an engine for aircraft.
- An active technology is e.g. in the magazine aeroacoustics volume 1, number 1, 2002, p. 53.
- Loudspeakers in the form of vibrating membranes are used to create a secondary sound field that cancels the primary sound field.
- the loudspeakers or actuators are arranged in the immediate vicinity of the sound generation of the primary sound field, namely on the stator blades of an engine.
- the levels generated are limited due to the available ones
- Installation volume is very small, so that only a very small proportion of the primary sound field can be reduced. This means that the generation of high sound levels is hardly possible with acoustic actuators, since the size, weight and power consumption are too high for many applications.
- Hybrid concepts are also known in which passive elements are used for sound absorption. Resonance properties are often exploited, for example through the use of Helmholtz resonators.
- the above-mentioned aeroacoustics volume 1, number 1, 2002 shows on page 52 an active Helmholtz resonator for sound absorption in an engine. Since the effect of a Helmholtz resonator is limited to a narrow frequency range, active elements are used to adapt the properties of the resonator to the respective requirements, for example to the changes in the rotor speeds.
- tones are suppressed in the prior art, which arise from the overflow of cavities.
- the sound is caused by instabilities in the flow.
- the cavities strongly stimulate these disturbances for certain frequencies, so that very loud tones are produced as a result.
- Actuators are used to suppress these tones and prevent the sound that arises.
- the resonator properties are influenced by means of the actuators in such a way that the instability of the flow is not fanned. The interaction of instability with the resonance properties of the chamber is thus suppressed.
- anti-noise is generated in an exhaust duct with a loudspeaker.
- the device for active noise control comprises a housing in which a chamber is formed, and a chamber opening which is formed in a wall of the chamber, the chamber opening being arranged or to be arranged laterally on a gas stream, and an adjustable deflection device being arranged on the chamber opening is arranged which, in a first position, at least partially guides the gas stream flowing past the chamber opening into the chamber in order to compress the gas there, and in a second position supplies the gas from the chamber to the gas stream in order to supply the gas located in the chamber relax.
- the device according to the invention has a very high efficiency.
- the necessary energy is taken from the gas or air flow, whereby this air flow can be constant. Only a small amount of power is required for control, which is only used to deflect the air flow.
- the construction of the device according to the invention is relatively simple and requires little space and weight.
- an aeroacoustic sound generation mechanism which is also responsible for the sound generation when blowing pipes and cavities, is used to generate high sound pressures.
- the sound generation is triggered by instabilities in the free boundary layer flow. These fluctuations in pressure and speed of the flow are coupled with an acoustic resonator.
- the resonator formed by the chamber causes the fluctuation components to be fed back to the point of origin of the free boundary layer. This response of the resonator generates for certain frequencies Feedback conditions that fuel instability, that is, resonance occurs. After a certain settling time, this process generates strong pressure fluctuations in the resonator and radiates it as sound.
- the present invention takes advantage of these effects in order to reduce the sound in a flow or in a flow channel.
- the stochastic excitation due to the instability in the boundary layer flow is dispensed with and a deflection device is used in its place. This device enables deterministic excitation of the sound generation process, or deflection and deflection of the air flow into the chamber volume.
- this sound generator is suitable for active sound control.
- the adjustable deflection device generates an alternating pressure in the chamber and radiates it as sound through the chamber opening. This emitted sound is superimposed on the primary sound field and reduces it.
- the frequency of the emitted sound can be determined by the time period during which the deflection unit is in the first and in the second
- the phase of the sound pressure fluctuations has a fixed relationship to the phase of the air flow introduced into the chamber. It depends on Sound pressure from the amount of air introduced into the chamber or the amplitude of the excitation signal for the deflection device and the chamber volume.
- the deflection device advantageously comprises a flap which is arranged pivotably about an axis, the axis being directed perpendicularly to the direction of flow of the gas stream.
- the deflection device can also be designed as a swingable plate clamped on one side.
- the chamber is preferably designed as a resonator, the deflection device being positioned on an upstream edge of the chamber opening.
- the air flow is advantageously deflected in proportion to the excitation signal of the deflection device.
- a flow channel for the gas flow is preferably arranged at least upstream of the chamber opening and is used to guide the gas flow past the chamber opening.
- the flow channel can either be part of the device according to the invention, or the device according to the invention is designed such that an existing flow channel, for example in an engine, is used accordingly.
- the deflection device comprises a deflection surface which faces the gas flow in the first position and is directed obliquely to the gas flow, and which faces away from the gas flow and is directed obliquely to the gas flow in the second position.
- the device advantageously comprises a control and / or drive unit which is coupled to the deflection device.
- the deflection device can for example, comprise an elastic element. As a result, a restoring force is exerted on the deflection device, which acts in the direction of the zero position, so that the deflection device works effectively and effectively even at elevated frequencies.
- the chamber preferably comprises an adjustable chamber wall. This means that the chamber volume can be adapted to the respective requirements.
- the sound pressure generated by the device according to the invention in operation depends on the chamber volume and the amount of air introduced into the chamber. The sound pressure can thus be flexibly adjusted due to the adjustable chamber wall.
- gas flow is formed by the inlet flow of an engine.
- energy required for sound control of engines is taken directly from the gas or air flow, so that no complex energy supplies are required to operate the device.
- the gas flow can be formed from a separate compressed air supply.
- the gas or air flow can be generated from existing units, the compressed air supply being an example of such a unit.
- the flow channel can be formed by an engine inlet of an aircraft.
- the device according to the invention in an engine, in particular in an aircraft engine.
- a method for active noise control comprises the following steps: at least partially redirecting a gas stream into a chamber to increase the pressure in the chamber;
- the method according to the invention can produce very loud sound levels for sound suppression, although only a low power is required for this. This means that the method according to the invention results in a particularly high degree of efficiency, since the energy for sound control is taken from the gas or air flow present.
- the method according to the invention is advantageously carried out with the device according to the invention.
- it can be carried out when operating an engine.
- the sound radiation from engines can be significantly reduced.
- the features and advantages mentioned above with regard to the device also apply to the method according to the invention.
- an engine for aircraft which comprises an inventive device for active noise control, as described here.
- FIG. 1a-d schematically show a preferred embodiment of the invention in different operating phases as a sectional view.
- FIG. 1a A device 10 for sound absorption in a first operating phase is shown in FIG. 1a.
- the device 10 comprises a housing 11, in the interior of which a chamber 12 is formed.
- the chamber 12 has a wall 12a Chamber opening 13, which is located on one side of the chamber 12, which is swept by an air or gas stream 14 during operation.
- the wall 12a of the chamber 12, in which the chamber opening 13 is located, is aligned parallel to the direction of the gas stream 14 located upstream of the chamber 12.
- a deflection device 15 is arranged, which in the present example has the shape of a plate.
- the deflection device 15 is pivotally mounted about an axis A, which is directed perpendicular to the direction of the gas stream 14 brought in.
- the plate-shaped deflection device 15 can assume various positions which allow the gas flow 14 to be at least partially directed into the chamber or to supply gas from the chamber 12 to the gas flow 14 passing the chamber opening 13.
- the deflection device 15 is tilted with respect to the gas flow 14, so that the incoming gas hits the inclined underside 15 a of the deflection device 15, so that it is deflected in its flow direction and guided into the chamber 12.
- an increased pressure or counter pressure builds up there due to the gas flowing into the chamber 12.
- a flow channel 17 is formed, which serves to guide the gas flow 14 and can be part of the device 10.
- the device 10 it is also possible for the device 10 to be connected laterally to an existing flow channel.
- the chamber 12 has an adjustable chamber wall 18 on one side, so that the chamber volume can be variably adjusted.
- the adjustable chamber wall 18 is arranged on the side of the chamber 12 opposite the chamber opening 13.
- a control and drive mechanism is coupled to the adjustable chamber wall 18 in order to control the chamber volume and to adapt it as required.
- FIG. 1b shows the device 10 in a second phase (90 °) in which the plate-shaped deflection device 15 is directed parallel to the direction of the gas flow 14. In this position, the gas flow 14 is not deflected, but rather passes over the chamber opening 13 above the plate-shaped deflection device 15, so that the gas is guided past the chamber 12.
- the pressure in chamber 12 has reached its maximum value.
- the pressure is schematically symbolized by circles, the diameter being a measure of the amplitude.
- the black circles in FIG. 1b indicate an overpressure present in the chamber 12 compared to the areas of the gas flow lying outside the chamber 12.
- 1c shows the device 10 in a third phase (180 °), in which the deflection device 15 is tilted in such a way that the gas flowing in the flow channel 17 is directed past its top and does not enter the chamber 12, while on the other hand the Gas in the chamber 12 can exit through the chamber opening 13, so that the gas in the chamber can expand. That is, the deflection device 15 is inclined with respect to the flow direction of the gas flow 14, so that the chamber opening 13 is closed to the gas flowing in. On the underside 15a of the tilted deflection device 15, the gas from the chamber 12 is fed to the gas stream which is directed past the top.
- FIG. 1d shows the device 10 according to the invention in a fourth phase (270 °) in which there is a pressure minimum in the chamber 12.
- the pressure minimum has arisen in this phase due to the inertia of the expansion process shown in Fig. 1c.
- the deflection device 15 is again parallel to the direction of the gas flow 14 aligned, so that the gas flow 14 by means of the deflection device 15 is directed past the chamber opening 13.
- the negative pressure existing in this phase in chamber 12 is symbolized by the white circles in FIG. 1d.
- the cycle starts again, i.e. corresponding to the first phase, gas or air, is guided into the chamber 12 by means of the deflection device 15, and the further phases are then run through.
- the deflection device 15 directs the air or gas flow into the chamber 12 in a controllable manner, and an alternating pressure is generated in the chamber 12 by adjusting the deflection device 15.
- the alternating pressure is emitted as sound through the chamber opening 13.
- the air or gas flow is deflected in proportion to the excitation signal of the deflection device 15.
- the frequency of the emitted sound is determined by the duration of the phases shown.
- the phase of the sound pressure fluctuations has a fixed relationship to the phase of the gas flow introduced into the chamber 12.
- the sound pressure depends on the amount of air introduced into the chamber 12 and the chamber volume.
- the amplitude of the excitation signal for the deflection device 15 is used to control the amount of air introduced.
- the chamber volume is adjusted by the adjustable chamber wall 18.
- aeroacoustic sound generation mechanisms are used to control sound.
- the required energy is taken from the available gas flow.
- the gas flow is diverted into the chamber 12 attached to the side, where it is braked and compressed due to the limited chamber volume.
- the gas stream is then directed past the chamber opening 13, the compressed gas in the chamber 12 being able to relax via the chamber opening 13.
- the sound caused by the change in density is emitted through the chamber opening 13. shine. It overlaps with the disturbing original sound field and leads to the partial extinction of the originally existing, disturbing sound by suitable control of the phases and frequencies.
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- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Acoustics & Sound (AREA)
- Multimedia (AREA)
- Exhaust Silencers (AREA)
Abstract
Description
Claims
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US10/520,420 US7273130B2 (en) | 2002-07-16 | 2003-07-09 | Device and method for active soundproofing, and power unit for aeroplanes |
DE50302683T DE50302683D1 (de) | 2002-07-16 | 2003-07-09 | Vorrichtung und verfahren zur aktiven schallbekämpfung sowie triebwerk für flugzeuge |
JP2004528354A JP4361866B2 (ja) | 2002-07-16 | 2003-07-09 | 能動的に騒音を低減するための装置と方法、ならびに航空機用のエンジン |
EP03787640A EP1522062B1 (de) | 2002-07-16 | 2003-07-09 | Vorrichtung und verfahren zur aktiven schallbekämpfung sowie triebwerk für flugzeuge |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE10232291A DE10232291B4 (de) | 2002-07-16 | 2002-07-16 | Vorrichtung und Verfahren zur aktiven Schallbekämpfung sowie Triebwerk für Flugzeuge |
DE10232291.0 | 2002-07-16 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2004017301A1 true WO2004017301A1 (de) | 2004-02-26 |
Family
ID=30010087
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/DE2003/002292 WO2004017301A1 (de) | 2002-07-16 | 2003-07-09 | Vorrichtung und verfahren zur aktiven schallbekämpfung sowie triebwerk für flugzeuge |
Country Status (5)
Country | Link |
---|---|
US (1) | US7273130B2 (de) |
EP (1) | EP1522062B1 (de) |
JP (1) | JP4361866B2 (de) |
DE (2) | DE10232291B4 (de) |
WO (1) | WO2004017301A1 (de) |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2005111993A1 (ja) * | 2004-05-14 | 2005-11-24 | Yanmar Co., Ltd. | キャビンの制音構造 |
DE102019106685B4 (de) * | 2019-03-15 | 2021-01-21 | Hochschule für Angewandte Wissenschaften Hamburg | Schallabsorber mit einem Helmholtz-Resonator |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH06348280A (ja) * | 1993-06-03 | 1994-12-22 | Sekisui Chem Co Ltd | ダクト用消音装置 |
US6069840A (en) * | 1999-02-18 | 2000-05-30 | The United States Of America As Represented By The Secretary Of The Air Force | Mechanically coupled helmholtz resonators for broadband acoustic attenuation |
US6112514A (en) * | 1997-11-05 | 2000-09-05 | Virginia Tech Intellectual Properties, Inc. | Fan noise reduction from turbofan engines using adaptive Herschel-Quincke tubes |
Family Cites Families (13)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5970868A (ja) * | 1982-10-15 | 1984-04-21 | Nippon Denso Co Ltd | 容積可変式共鳴消音システム |
US5283398A (en) * | 1989-12-26 | 1994-02-01 | Tsuchiya Mfg. Co., Ltd. | Resonator type silencer |
DE4228356C2 (de) * | 1992-08-26 | 1995-10-19 | Daimler Benz Aerospace Ag | Hohlraumresonator zur Lärmreduzierung |
DE29611884U1 (de) * | 1996-07-09 | 1997-11-06 | ABS Gesellschaft für Automatisierung, Bildverarbeitung und Software mbH, 07745 Jena | Einrichtung zur Kompression von Luft oder Gasen mit akustischen Schwingungserzeugern |
DE29715756U1 (de) * | 1997-09-02 | 1998-03-19 | Lenz, Josef, 85614 Kirchseeon | Abgasresonanzsystem mit Klappensteuerung für Verbrennungsmotoren aller Art |
ES2174642T3 (es) * | 1998-08-11 | 2002-11-01 | Siemens Ag | Dispositivo para la depuracion catalitica de gas de escape. |
DE19853359A1 (de) * | 1998-11-19 | 2000-05-31 | Daimler Chrysler Ag | Verbrennungsmotor mit Abgasschalldämpfer und Verfahren zu dessen Betrieb |
DE19958748B4 (de) * | 1999-12-07 | 2005-07-28 | Webasto Ag | Vorrichtung zur Beeinflussung der Luftströmung |
DE20003519U1 (de) * | 2000-02-25 | 2000-06-08 | Wolff Robert | Helmholtzresonator |
DE10112010B4 (de) * | 2001-03-13 | 2018-03-08 | Valeo Klimasysteme Gmbh | Luftführungskanal und Kraftfahrzeugs-Heiz-, Belüftungs- und oder Klimaanlage |
FR2836513B1 (fr) * | 2002-02-25 | 2005-12-02 | Renault Vehicules Ind | Ligne d'echappement et vehicule a moteur ainsi equipe |
US20040094360A1 (en) * | 2002-11-06 | 2004-05-20 | Calsonic Kansei Corporation | Acoustic dumper for exhaust system |
JP4375088B2 (ja) * | 2004-03-31 | 2009-12-02 | トヨタ紡織株式会社 | 可変消音器制御装置 |
-
2002
- 2002-07-16 DE DE10232291A patent/DE10232291B4/de not_active Expired - Fee Related
-
2003
- 2003-07-09 JP JP2004528354A patent/JP4361866B2/ja not_active Expired - Fee Related
- 2003-07-09 US US10/520,420 patent/US7273130B2/en not_active Expired - Fee Related
- 2003-07-09 WO PCT/DE2003/002292 patent/WO2004017301A1/de active IP Right Grant
- 2003-07-09 DE DE50302683T patent/DE50302683D1/de not_active Expired - Lifetime
- 2003-07-09 EP EP03787640A patent/EP1522062B1/de not_active Expired - Fee Related
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH06348280A (ja) * | 1993-06-03 | 1994-12-22 | Sekisui Chem Co Ltd | ダクト用消音装置 |
US6112514A (en) * | 1997-11-05 | 2000-09-05 | Virginia Tech Intellectual Properties, Inc. | Fan noise reduction from turbofan engines using adaptive Herschel-Quincke tubes |
US6069840A (en) * | 1999-02-18 | 2000-05-30 | The United States Of America As Represented By The Secretary Of The Air Force | Mechanically coupled helmholtz resonators for broadband acoustic attenuation |
Non-Patent Citations (1)
Title |
---|
RADAVICH P M ET AL: "A COMPUTATIONAL APPROACH FOR LOW-ACOUSTIC COUPLING IN CLOSED SIDE BRANCHES", JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA, AMERICAN INSTITUTE OF PHYSICS. NEW YORK, US, vol. 109, no. 4, April 2001 (2001-04-01), pages 1343 - 1353, XP001102789, ISSN: 0001-4966 * |
Also Published As
Publication number | Publication date |
---|---|
JP2005538286A (ja) | 2005-12-15 |
DE50302683D1 (de) | 2006-05-11 |
US7273130B2 (en) | 2007-09-25 |
US20050236225A1 (en) | 2005-10-27 |
JP4361866B2 (ja) | 2009-11-11 |
DE10232291B4 (de) | 2004-05-27 |
EP1522062B1 (de) | 2006-03-15 |
EP1522062A1 (de) | 2005-04-13 |
DE10232291A1 (de) | 2004-02-05 |
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