CN111564149B - Cavity structure noise control method and device based on controllable impedance boundary - Google Patents
Cavity structure noise control method and device based on controllable impedance boundary Download PDFInfo
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- CN111564149B CN111564149B CN202010364109.9A CN202010364109A CN111564149B CN 111564149 B CN111564149 B CN 111564149B CN 202010364109 A CN202010364109 A CN 202010364109A CN 111564149 B CN111564149 B CN 111564149B
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Classifications
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- 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
- G10K11/161—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general in systems with fluid flow
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- 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
- G10K11/162—Selection of materials
Abstract
The invention belongs to the field of noise control, and discloses a cavity structure noise control method based on a controllable impedance boundary.
Description
Technical Field
The invention belongs to the field of noise control, and particularly relates to a cavity structure noise control method and device based on a controllable impedance boundary.
Background
When fluid flows through the cavity structure, strong self-excited vibration phenomena occur in the cavity due to interaction between flow of the shear layer outside the cavity and flow in the cavity, strong pressure, speed and other pulsation are generated, and strong noise is accompanied, and radiation propagation is carried out outwards and towards the front end of the cavity, and the phenomena are called cavity flow-excited oscillation. The problems relate to unsteady flow, flow instability, interaction between sound and flow and the like, are one of hot problems in research of fluid mechanics, and are frequently encountered in engineering practice, such as a buried missile cabin in an aircraft, a landing gear cabin, a high-speed railway carriage gap, an automobile skylight and the like. In order to effectively change the flowing state in the cavity and inhibit strong cavity noise, a series of researches are carried out by a plurality of research institutions at home and abroad aiming at cavity flowing and cavity noise.
The cavity structure flow and noise control methods are mainly divided into active control methods (such as front edge plasma excitation, front edge high frequency forcing force, front edge mass injection, etc.) and passive control methods (such as front edge spoiler, vortex generator, rear edge slope, etc.). The existing active control method often forms flow disturbance at the front edge of the cavity to influence the incoming flow condition, and the adopted method needs an additional mechanical actuating mechanism, an increased external excitation voltage and an air entraining system, so that the structure nearby the cavity structure is more complex, and the weight of the cavity structure is increased; the passive control method has the advantages that as the turbulence structure is added to the front edge of the cavity, the aerodynamic performance of the cavity structure area can be affected, the aerodynamic loss is used for noise reduction, and practical engineering application is difficult to obtain.
Disclosure of Invention
The purpose of the invention is that: the cavity structure noise control method and device based on the controllable impedance boundary has the advantages of simple configuration and good noise reduction effect, and the occurrence and continuation of the propagation and the acoustic-vortex coupling of the noise in the cavity under the airflow environment of the cavity structure are restrained, so that the noise in the cavity structure is reduced.
The technical scheme of the invention is as follows: in one aspect, a method for controlling noise in a cavity structure based on a controllable impedance boundary is provided, the cavity structure including a leading edge, a cavity having an opening at one end, and a trailing edge, an airflow flowing from the leading edge to the trailing edge of the cavity structure,
the control method comprises the following steps: replacing a bottom plate of the cavity with a micro-perforated plate, and arranging rigid wall plates at intervals on one side of the micro-perforated plate far away from the airflow; the microperforated panel and the rigid wall panel are both connected with the side wall of the cavity, and a gap exists between the microperforated panel and the rigid wall panel.
Further, the rigid wall plate is movably connected with the side wall of the cavity, and the distance between the rigid wall plate and the microperforated panel is adjustable.
Further, a sound absorbing material is disposed between the microperforated panel and the rigid wall panel.
Further, a sensor is arranged on one side of the microperforated panel close to the airflow, and a plurality of speakers are arranged on one side of the rigid wall plate far from the microperforated panel;
and adjusting the excitation voltage of the loudspeaker according to the acoustic parameter information fed back by the sensor so as to enable the tympanic membrane at the top end of the loudspeaker to vibrate to different degrees, and changing the thickness of an air layer between the tympanic membrane and the microperforated plate.
Further, a sound absorbing material is disposed between the microperforated panel and the rigid wall panel.
In another aspect, a method for noise control of a cavity structure based on a controllable impedance boundary is provided, the cavity structure including a leading edge, a cavity having an opening at one end, and a trailing edge, an airflow flowing from the leading edge to the trailing edge of the cavity structure,
the control method comprises the following steps: replacing a bottom plate of the cavity with a micro-perforated plate, and arranging electric drive soft shells at intervals on one side of the micro-perforated plate far away from the airflow; the micro-perforated plate and the electric drive soft shell are connected with the side wall of the cavity, and a gap exists between the micro-perforated plate and the electric drive soft shell; and adjusting the driving voltage of the electric drive soft shell to drive the electric drive soft shell to move relative to the microperforated panel.
Further, a sensor is arranged on the inner wall of the cavity above the microperforated panel; and adjusting the driving voltage of the electric drive soft shell according to the acoustic parameter information fed back by the sensor, and driving the electric drive soft shell to move relative to the microperforated panel.
Further, a sound absorbing material is disposed between the microperforated panel and the electrically driven bladder.
In still another aspect, a noise control device of a cavity structure based on a controllable impedance boundary is provided, the cavity structure comprises a front edge, a cavity with one end open and a rear edge, airflow flows from the front edge to the rear edge of the cavity structure, a bottom plate of the cavity is a micro-perforated plate, and a rigid wall plate or an electric drive soft shell is arranged on one side of the micro-perforated plate away from the airflow at intervals; the rigid wall plate or the electric drive soft shell is connected with the side wall of the cavity; a gap exists between the microperforated panel and the rigid wall panel or electrically driven bladder.
The invention has the technical effects that:
according to the invention, the movable rigid wallboard or the electric drive soft shell is added behind the microperforated panel, and the transmission of noise in the cavity is absorbed and restrained by adjusting the position of the rigid wallboard and the position of the electric drive soft shell behind the microperforated panel, so that the purpose of reducing the noise is achieved.
In the invention, the sound absorption material is arranged between the micro-perforated plate and the rigid wallboard or the electric drive soft shell to absorb noise; if no sound absorbing material is placed between the microperforated panel and the rigid wall panel or electrically driven bladder, sound energy is dissipated by air vibration.
Under the prior art condition and test condition, the method with simple structure can play a good role in suppressing cavity noise, and particularly has a good effect in suppressing the amplitude of sound pressure level at the main peak frequency of the cavity structure. The method has the advantages of relatively simple structure, good reliability, better applicability, easy popularization and application, and great engineering practical application and military value.
Drawings
FIG. 1 is a schematic diagram of a cavity structure;
FIG. 2 is a schematic diagram of the noise reduction principle of embodiment 1;
FIG. 3 is a schematic diagram of the noise reduction principle of embodiment 2;
fig. 4 is a schematic diagram of the noise reduction principle of embodiment 3.
Detailed Description
When air flows through the cavity structure, strong self-oscillation phenomenon can occur in the cavity due to interaction of flow of the shear layer outside the cavity and flow in the cavity, strong pressure and speed pulsation can be generated, air flow impacts the rear wall of the cavity, strong noise can be generated, one part of generated noise can be transmitted to the outside of the cavity, the other part of generated noise is transmitted from the rear edge area of the cavity to the front edge area of the cavity, and the noise transmitted to the front edge of the cavity can influence the flow of the shear layer at the front edge of the cavity and the formation of vortex after reaching the front edge of the cavity, so that the cavity noise is more serious.
The technical conception of the invention: the invention provides a cavity structure noise control method based on controllable impedance boundary, which replaces a cavity structure bottom plate with a micro-perforated plate, adds a movable rigid wallboard or an electric drive soft shell after the micro-perforated plate, changes the acoustic impedance of the boundary wall surface of the cavity structure by adjusting the position of the rigid wallboard and the position of the electric drive soft shell after the micro-perforated plate, attenuates the process of generating noise forward propagation on the cavity structure rear edge, reduces the noise amplitude reaching the unstable shear layer of the cavity front edge, inhibits the unstable shear layer from generating new shedding vortex, and reduces the occurrence and the continuation of acoustic-vortex coupling in the cavity structure cavity, thereby achieving the purpose of reducing noise.
The acoustic impedance of the surface of the cavity bottom plate structure can be changed by reasonably designing the distance between the microperforated plate and the rigid wall plate, so that the acoustic impedance of the microperforated plate is matched with the optimal impedance, the method of adding the rigid wall plate after the microperforated plate is mainly aimed at single frequency, and the distance between the microperforated plate and the rigid wall plate is sharply increased along with the lowering of noise frequency. The cavity noise has obvious peak noise, the cavity peak noise is usually mainly the second order, the method for adding the rigid wallboard after micropunching is mainly aimed at the second order peak frequency with the largest cavity sound pressure level amplitude, the range of the second order peak frequency can be calculated according to the cavity geometric dimension and the incoming flow speed through theoretical formulas, and the sound pressure level amplitude at the second order peak frequency of the cavity can be reasonably reduced by reasonably designing the geometric parameters of the micropunching plate and the distance between the micropunching plate and the rigid wallboard.
The microperforated panel and electric drive soft shell double-layer structure is mainly optimized continuously through a control algorithm and a control target, noise control in a wider frequency range can be achieved, a reasonable error sensor is adopted to obtain the acoustic impedance and the particle vibration velocity of the surface of the microperforated panel, then the movement of the electric drive soft shell is regulated, and a better noise control effect can be achieved.
Example 1
In this embodiment, a cavity structure noise control method based on a controllable impedance boundary is provided, as shown in fig. 2, and fig. 2 is a schematic diagram of a noise reduction principle of embodiment 1. Fig. 1 is a schematic view of a cavity structure, and as shown in connection with fig. 1 and 2, the cavity structure 1 comprises a front edge 10 and a rear edge 20, a front wall 31 and a rear wall 32, from which the air flows. The noise control method of the present embodiment is as follows:
the bottom plate of the cavity is replaced by a micro-perforated plate 30, and a rigid wall plate 40 is arranged at a distance from one side of the micro-perforated plate 30 away from the airflow; microperforated panel 30 and rigid wall panel 40 are each connected to a side wall of the chamber. The side walls of the cavity comprise a front wall 31 and a rear wall 32.
In this embodiment, the microperforated panel and the rigid wall panel are not limited to being fixedly connected to the side wall of the cavity, and the rigid wall panel and the side wall of the cavity may be movably connected to each other, so that the distance between the rigid wall panel and the microperforated panel is adjustable.
As one of the preferred embodiments of the present embodiment, a gap exists between microperforated panel 30 and rigid wall panel 40, and acoustic energy is dissipated by air vibration between microperforated panel 30 and rigid wall panel 40.
Further, as one of the other preferred embodiments of the present embodiment, the present embodiment provides a sound absorbing material 50 between the microperforated panel 30 and the rigid wall panel 40, through which noise is absorbed.
In the noise control method provided by the embodiment, the cavity bottom plate is replaced by the micro-perforated plate, and the micro-perforated plate, the rigid wall plate and the sound absorption material form an impedance composite noise elimination structure. The structure has better sound absorption effect on noise with certain frequency and middle-high frequency noise. The cavity noise has obvious peak noise, and often takes the second order as the main part, the second order peak frequency can be calculated through a theoretical formula according to the geometric dimension and the incoming flow speed of the cavity, and the sound pressure level amplitude at the second order peak frequency of the cavity can be reasonably reduced through reasonably designing the geometric parameters (including the aperture, the thickness and the perforation rate) of the microperforated panel and the distance between the microperforated panel and the rigid wall panel, so that the purpose of reducing the cavity noise is achieved.
Example 2
In this embodiment, another method for controlling noise of a cavity structure based on a controllable impedance boundary is provided, as shown in fig. 3, and fig. 3 is a schematic diagram of a noise reduction principle of embodiment 2. As shown in connection with fig. 3, the cavity structure 1 comprises a leading edge 10 and a trailing edge 20, a leading wall 31 and a trailing wall 32, from which the air flow flows. The noise control method of the present embodiment is as follows:
firstly, replacing a bottom plate of a cavity with a micro-perforated plate 30, and arranging rigid wall plates 40 at intervals on one side of the micro-perforated plate 30 far away from the airflow; microperforated panel 30 and rigid wall panel 40 are each connected to a side wall of the chamber. The side walls include a front wall 31 and a rear wall 32.
Then, a sensor 60 is provided on the inner wall of the cavity above the microperforated panel, and a plurality of speakers 70 are arranged on the side of the rigid wall plate 40 remote from the microperforated panel 30. According to the acoustic parameter information fed back by the sensor, the excitation voltage of the loudspeaker is adjusted so as to enable the tympanic membrane 71 at the top end of the loudspeaker to vibrate to different degrees, and the excitation voltage is used for changing the thickness of an air layer between the tympanic membrane and the microperforated plate.
Further, in this embodiment, a small amount of sound absorbing material may be provided between the microperforated panel and the rigid wall panel.
According to the control method of the embodiment, the eardrum at the top end of the loudspeaker can vibrate to different degrees under different excitation voltages, the vibration enables the thickness of an air layer between the eardrum of the loudspeaker and the microperforated panel to be changed, and the impedance of the control structure is adjusted by matching with a control algorithm; the voltage is controlled according to the frequency and amplitude conditions of the main component of the cavity noise, so that the noise control of a wider frequency band can be realized.
Example 3
In this embodiment, another method for controlling noise of a cavity structure based on a controllable impedance boundary is provided, as shown in fig. 4, fig. 4 is a schematic diagram of the noise reduction principle of embodiment 3. As shown in connection with fig. 4 and 1, the cavity structure 1 comprises a leading edge 10 and a trailing edge 20, a leading wall 31 and a trailing wall 32. The noise control method of the present embodiment is as follows:
replacing the bottom plate of the cavity with a micro-perforated plate 30, and arranging electric drive soft shells 80 at intervals on one side of the micro-perforated plate 30 far away from the airflow; microperforated panel 30 and rigid wall panel 40 are each connected to a side wall of the chamber. The side walls include a front wall 31 and a rear wall 32. The electric drive soft shell 80 is driven to move relative to the microperforated panel by adjusting the drive voltage of the electric drive soft shell so as to adjust the distance between the electric drive soft shell and the microperforated panel. The electro-driven soft shell of the embodiment is made of piezoelectric materials or other materials capable of generating obvious displacement under voltage excitation, and the position of the electro-driven soft shell is moved through the adjustment of the intensity of external excitation voltage.
Further, a sensor 60 may be disposed on the inner wall of the cavity above the micro-perforated plate, and the driving voltage of the electro-conductive soft shell is adjusted according to the acoustic parameter information fed back by the sensor, so as to drive the electro-conductive soft shell 80 to move relative to the micro-perforated plate 30.
Further, a sound absorbing material may also be provided between the microperforated panel 30 and the electrically driven bladder 80.
In the control method provided by the embodiment, the microperforated panel and the electric drive soft shell are combined, the electric drive soft shell is a movable unit, and the electric drive soft shell can move below the microperforated panel along with different driving voltages, so that the distance between the microperforated panel and the electric drive soft shell can be adjusted, the position of the electric drive soft shell is adjusted by matching with a feedback sensor of a cavity rear wall area through a control algorithm and feedback parameters (including main frequency noise components of cavity noise), the wall impedance of a cavity structure is well matched with air impedance, and the noise control of a wider frequency band is realized.
According to the method provided by the invention, the cavity test device is designed, and after the test device is used in a test wind tunnel, the method is found to be used for well inhibiting the propagation of noise generated by the cavity structure, and effectively inhibiting the sound-vortex interference in the cavity structure. The micro-perforated plate geometric parameters, the air layer thickness, the loudspeaker vibration amplitude and the like can be reasonably designed according to the cavity structure geometric dimension and the incoming flow speed, so that a better noise reduction effect can be obtained, and the micro-perforated plate has a larger engineering practical application value and military value.
Claims (7)
1. A cavity structure noise control method based on controllable impedance boundary, the cavity structure includes a front edge, a cavity with one end open and a rear edge, the airflow flows from the front edge to the rear edge of the cavity structure, the method is characterized in that,
the control method comprises the following steps: replacing a bottom plate of the cavity with a micro-perforated plate, and arranging rigid wall plates at intervals on one side of the micro-perforated plate far away from the airflow; the micro-perforated plate and the rigid wall plate are connected with the side wall of the cavity, and a gap exists between the micro-perforated plate and the rigid wall plate;
the rigid wall plate is movably connected with the side wall of the cavity, and the distance between the rigid wall plate and the microperforated panel is adjustable.
2. The control method of claim 1, wherein a sound absorbing material is disposed between the microperforated panel and the rigid wall panel.
3. The control method according to claim 1, wherein,
a sensor is arranged on one side of the microperforated panel close to the airflow, and a plurality of speakers are arranged on one side of the rigid wall plate far from the microperforated panel;
and adjusting the excitation voltage of the loudspeaker according to the acoustic parameter information fed back by the sensor so as to enable the tympanic membrane at the top end of the loudspeaker to vibrate to different degrees, and changing the thickness of an air layer between the tympanic membrane and the microperforated plate.
4. A cavity structure noise control method based on controllable impedance boundary, the cavity structure includes a front edge, a cavity with one end open and a rear edge, the airflow flows from the front edge to the rear edge of the cavity structure, the method is characterized in that,
the control method comprises the following steps: replacing a bottom plate of the cavity with a micro-perforated plate, and arranging electric drive soft shells at intervals on one side of the micro-perforated plate far away from the airflow; the micro-perforated plate and the electric drive soft shell are connected with the side wall of the cavity, and a gap exists between the micro-perforated plate and the electric drive soft shell; adjusting the driving voltage of the electric drive soft shell to drive the electric drive soft shell to move relative to the microperforated panel; wherein the electric drive soft shell is made of piezoelectric materials.
5. The control method according to claim 4, wherein a sensor is provided on an inner wall of the cavity above the microperforated panel;
and adjusting the driving voltage of the electric drive soft shell according to the acoustic parameter information fed back by the sensor, and driving the electric drive soft shell to move relative to the microperforated panel.
6. The control method according to claim 4, wherein a sound absorbing material is provided between the microperforated panel and the electrically driven bladder.
7. The cavity structure noise control device based on the controllable impedance boundary comprises a front edge, a cavity with one end open and a rear edge, wherein air flow flows from the front edge to the rear edge of the cavity structure; the rigid wall plate or the electric drive soft shell is connected with the side wall of the cavity; gaps exist between the microperforated panel and the rigid wall panel or the electrically driven bladder;
wherein the electric drive soft shell is made of piezoelectric material; the rigid wall plate is movably connected with the side wall of the cavity, and the distance between the rigid wall plate and the microperforated panel is adjustable; the electric drive soft shell is movably connected with the side wall of the cavity, and the distance between the electric drive soft shell and the microperforated panel is adjustable.
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| CN112365872A (en) * | 2020-11-10 | 2021-02-12 | 国网北京市电力公司 | Noise reduction regulation and control method, device and system and processor |
| CN113270084A (en) * | 2021-05-12 | 2021-08-17 | 中国航空工业集团公司沈阳空气动力研究所 | Noise reduction device and method for aircraft cavity based on sound absorption material |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101828988A (en) * | 2010-05-20 | 2010-09-15 | 中南大学 | Active sound absorption adjustable and noiseproof earplug with composite structure |
| WO2010147272A1 (en) * | 2009-06-15 | 2010-12-23 | 한국과학기술원 | Semi-active sound absorption system and method thereof |
| CN102044239A (en) * | 2009-10-22 | 2011-05-04 | 北京绿创声学工程股份有限公司 | Micro-perforated plate with resonant sound absorption structure |
| GB201708245D0 (en) * | 2017-05-23 | 2017-07-05 | Kp Acoustics Ltd | Acoustic resonators |
| CN107542514A (en) * | 2017-09-08 | 2018-01-05 | 合肥工业大学 | A kind of adaptive bipolar microperforated panel silencer |
| CN107782523A (en) * | 2017-10-31 | 2018-03-09 | 中国空气动力研究与发展中心高速空气动力研究所 | A kind of new cavity modal noise standing wave decomposition method |
| CN108867986A (en) * | 2018-07-02 | 2018-11-23 | 长春理工大学 | Combined frequency-change acoustic tile |
-
2020
- 2020-04-30 CN CN202010364109.9A patent/CN111564149B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2010147272A1 (en) * | 2009-06-15 | 2010-12-23 | 한국과학기술원 | Semi-active sound absorption system and method thereof |
| CN102044239A (en) * | 2009-10-22 | 2011-05-04 | 北京绿创声学工程股份有限公司 | Micro-perforated plate with resonant sound absorption structure |
| CN101828988A (en) * | 2010-05-20 | 2010-09-15 | 中南大学 | Active sound absorption adjustable and noiseproof earplug with composite structure |
| GB201708245D0 (en) * | 2017-05-23 | 2017-07-05 | Kp Acoustics Ltd | Acoustic resonators |
| CN107542514A (en) * | 2017-09-08 | 2018-01-05 | 合肥工业大学 | A kind of adaptive bipolar microperforated panel silencer |
| CN107782523A (en) * | 2017-10-31 | 2018-03-09 | 中国空气动力研究与发展中心高速空气动力研究所 | A kind of new cavity modal noise standing wave decomposition method |
| CN108867986A (en) * | 2018-07-02 | 2018-11-23 | 长春理工大学 | Combined frequency-change acoustic tile |
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