CN111739503B - Petal type inner inserting tube type Helmholtz resonance sound absorption structure - Google Patents
Petal type inner inserting tube type Helmholtz resonance sound absorption structure Download PDFInfo
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- CN111739503B CN111739503B CN202010484707.XA CN202010484707A CN111739503B CN 111739503 B CN111739503 B CN 111739503B CN 202010484707 A CN202010484707 A CN 202010484707A CN 111739503 B CN111739503 B CN 111739503B
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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
- G10K11/172—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using resonance effects
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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
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- 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
- Y02T90/00—Enabling technologies or technologies with a potential or indirect contribution to GHG emissions mitigation
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- Acoustics & Sound (AREA)
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- Building Environments (AREA)
- Soundproofing, Sound Blocking, And Sound Damping (AREA)
Abstract
The invention provides a petal-shaped inner insertion tube type Helmholtz resonance sound absorption structure, which is characterized in that a Helmholtz resonance cavity is formed by welding or cementing a cavity body and a petal-shaped inner insertion tube, and radial roughness is introduced on the inner wall of the inner insertion tube, so that the acoustic impedance characteristic of the structure is improved, the low-frequency sound absorption performance of the structure is improved, and the sound absorption bandwidth of the structure is widened. The cavity structure reduces the weight of the structure and ensures the bearing performance of the structure on the premise of realizing good low-frequency sound absorption performance.
Description
Technical Field
The invention relates to the field of underwater sound absorption, in particular to a petal-shaped inner-tube type Helmholtz resonance sound absorption structure.
Background
The helmholtz resonator is a typical resonance sound absorption structure, and in practical application, the helmholtz resonator is generally constructed by a microperforated panel and a back cavity, and sound waves in the air are absorbed through helmholtz resonance, so that vibration and noise reduction designs of a movie theatre, a conference room and a car cabin are realized. However, for the micro-perforated plate structure, to achieve efficient absorption of sound waves in lower frequency band, it is necessary to increase the thickness of the micro-perforated plate and reduce the aperture of the micro-perforations, which results in an increase in the mass and volume of the structure, which is disadvantageous for lightweight design and manufacturing. In addition, the hole patterns of the microperforations are generally regular cylindrical holes, so that the damping inside the hole patterns is smaller, and the sound absorption bandwidth is not beneficial to increase and the low-frequency sound absorption performance is improved.
Disclosure of Invention
The invention provides a petal-shaped inner-tube type Helmholtz resonance sound absorption structure for solving the problems of narrow bandwidth, poor low-frequency sound absorption performance, difficult processing and manufacturing, larger size and poor light weight performance of the traditional air sound absorption structure.
The invention provides a petal-shaped inner inserting tube type Helmholtz resonance sound absorption structure which comprises a cavity and a petal-shaped inner inserting tube, wherein the cavity is connected with the petal-shaped inner inserting tube through welding or gluing to form the petal-shaped inner inserting tube type Helmholtz resonance sound absorption structure.
According to the invention, the Helmholtz resonant cavity is formed by welding or cementing the cavity and the petal-shaped inner insertion pipe, and radial roughness is introduced on the inner wall of the inner insertion pipe, so that the acoustic impedance characteristic of the structure is improved, the low-frequency sound absorption performance of the structure is improved, and the sound absorption bandwidth of the structure is widened. The cavity structure reduces the weight of the structure and ensures the bearing performance of the structure on the premise of realizing good low-frequency sound absorption performance.
Specifically, the cavity is made of hard materials such as structural steel, resin, wood or composite materials, the upper surface is provided with a small hole, the lower surface is fixed on the surface of a wall body needing acoustic treatment, and the structural steel has good bearing performance due to the application.
Further, the diameter of the cavity is 20-30 mm, the cavity is used as a Helmholtz resonant cavity, the effect of sound volume is achieved, and the peak sound absorption frequency of the structure can be controlled by adjusting the diameter of the cavity.
Further, the height of the cavity is 30-50 mm, the size of the resonant cavity is determined by the height of the cavity, and the sound absorption frequency band of the structure can be adjusted by changing the height of the cavity.
Specifically, the petal-shaped inner insertion tube is made of structural steel, resin, wood or composite materials and other hard materials, is connected with the opening on the cavity through welding or cementing, and is arranged to enable the inside of the cavity to be communicated with the outside, and air flows into the inside of the cavity through the petal-shaped inner insertion tube to form a Helmholtz resonant cavity.
Further, the average diameter of the petal-shaped inner insertion pipe is 3-5 mm, the diameter of the air column in the pipe is determined by the diameter of the petal-shaped inner insertion pipe, and the Helmholtz resonance characteristic of the structure can be changed by adjusting the diameter of the petal-shaped inner insertion pipe, so that the sound absorption performance of the structure is adjusted.
Further, the relative roughness of the petal-shaped inner insertion tube is 0.15-0.25, the diameter change amplitude of the air column in the tube is determined by the relative roughness of the petal-shaped inner insertion tube, the acoustic impedance of the structure can be regulated and controlled by regulating the relative roughness of the petal-shaped inner insertion tube, and the regulation and control of the sound absorption performance of the structure are realized.
Further, the space wave number of the petal-shaped inner insertion tube is 4-8, the diameter change condition of the air column in the tube is determined by the space wave number of the petal-shaped inner insertion tube, the acoustic impedance of the structure can be regulated and controlled by regulating the space wave number of the petal-shaped inner insertion tube, and the regulation and control of the sound absorption performance of the structure are realized.
Further, the length of the petal-shaped inner insertion tube is 25-40 mm, the height of the air column in the perforation is determined by the length of the petal-shaped inner insertion tube, and the resonance sound absorption characteristic of the structure is controlled.
The invention has the beneficial effects that:
1. has excellent low-frequency sound absorption performance. The sound absorption coefficient of the test piece at a certain frequency of 100-400 Hz can reach more than 0.99, and perfect sound absorption is realized. Compared with the traditional structure, the sound absorption coefficient of the sound absorption device moves 18% -35% towards low frequency, and the peak value of the sound absorption coefficient is improved by 5%. The structural thickness is only 1/36-1/33 of the corresponding perfect sound absorption wavelength, and the sound absorption metamaterial is a deep sub-wavelength scale low-frequency perfect sound absorption metamaterial.
2. Has good bearing performance and light weight performance. The cavity is made of hard materials such as structural steel, and the structure has good pressure resistance and is a bearing and light-weight multifunctional structure.
3. With more adjustable parameters and variables. The diameter of the cavity, the height of the cavity, the diameter of the petal-shaped inner insertion tube, the relative roughness of the petal-shaped inner insertion tube, the space wave number of the petal-shaped inner insertion tube and the length of the petal-shaped inner insertion tube are all adjustable parameters, and the parameters can be selected and adjusted according to specific use scenes, such as the requirement on bearing performance or the requirement on acoustic performance reasonably.
4. Simple structure and easy manufacture.
Drawings
Fig. 1 is a schematic diagram of a helmholtz resonance sound absorption structure of a petal-shaped inner tube type, in which (a) is a schematic diagram of a helmholtz resonance sound absorption structure of a petal-shaped inner tube type, (b) is a sectional view of a helmholtz resonance sound absorption structure of a petal-shaped inner tube type, and (c) is a sectional view of a petal-shaped inner tube type;
fig. 2 is a schematic diagram of sound absorption coefficients within 100-400 hz according to three embodiments of the present invention.
Wherein: 1. a cavity; 2. petal-shaped inner cannula.
Detailed Description
In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "one side", "one end", "one side", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present invention. Furthermore, in the description of the present invention, unless otherwise indicated, the meaning of "a plurality" is two or more.
In the description of the present invention, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present invention will be understood in specific cases by those of ordinary skill in the art.
According to the petal-shaped inner insertion tube type Helmholtz resonance sound absorption structure, the Helmholtz resonance cavity is formed by welding or gluing the cavity body 1 and the petal-shaped inner insertion tube 2, and radial roughness is introduced into the inner wall of the inner insertion tube 2, so that the acoustic impedance characteristic of the structure is improved, the low-frequency sound absorption performance of the structure is improved, and the sound absorption bandwidth of the structure is widened. The cavity 1 structure reduces the structural weight and ensures the structural bearing performance on the premise of realizing good low-frequency sound absorption performance, and solves the problems of narrow bandwidth, poor low-frequency sound absorption performance, difficult processing and manufacturing, larger size and poor light weight performance of the traditional microperforated panel sound absorption structure.
Referring to fig. 1, the petal-shaped inner insertion tube type helmholtz resonance sound absorption structure comprises a cavity 1 and a petal-shaped inner insertion tube 2, wherein the cavity 1 and the petal-shaped inner insertion tube 2 are connected through welding or gluing to form the petal-shaped inner insertion tube type helmholtz resonance sound absorption structure.
The cavity 1 is made of hard materials such as structural steel, resin, wood or composite materials, the upper surface is provided with a small hole, the lower surface is fixed on the surface of a wall body to be acoustically treated, the diameter of the cavity 1 is 20-30 mm, the shape is cylindrical, cuboid, hexagonal prism or irregular, and the height of the cavity 1 is 30-50 mm.
The petal-shaped inner insertion tube 2 is made of hard materials such as structural steel, resin, wood or composite materials and is connected with an opening on a cavity through welding or gluing, the radial roughness of the inner wall of the petal-shaped inner insertion tube 2 is characterized by a function f=dX [ 0.5-delta cos (nx) ], d is the average diameter of the petal-shaped inner insertion tube, delta is the relative roughness of the petal-shaped inner insertion tube, n is the space wave number of the petal-shaped inner insertion tube, x is the coordinate along the length direction of the petal-shaped inner insertion tube, the average diameter of the petal-shaped inner insertion tube 2 is 3-5 mm, the relative roughness of the petal-shaped inner insertion tube 2 is 0.15-0.25, the space wave number of the petal-shaped inner insertion tube 2 is 4-8, and the length of the petal-shaped inner insertion tube 2 is 25-40 mm.
For the purpose of making the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the described embodiments are some embodiments of the present invention, but not all embodiments of the present invention. The components of the embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the invention, as presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
The invention consists of a cavity and a petal-shaped inner insertion tube, the sound absorption performance of which is mainly determined by the parameters of a resonance cavity, and the sound absorption performance of the inner insertion tube comprises the diameter of the cavity, the height of the cavity, the diameter of the petal-shaped inner insertion tube, the relative roughness of the petal-shaped inner insertion tube, the space wave number of the petal-shaped inner insertion tube and the length of the petal-shaped inner insertion tube. The load bearing and light weight properties are mainly determined by the cavity dimensions, including cavity diameter and cavity height. Because these structural parameters are all adjustable parameters, can realize corresponding sound absorption, bear and lightweight performance requirement through adjusting. The technical scheme of the invention is exemplified by the following specific examples.
Examples materials:
structural steel: it is characterized by a density of 7850kg/m 3 Young's modulus 200GPa, poisson's ratio 0.2.
Air: it is characterized by a density of 1.29kg/m 3 Sound velocity 343m/s, dynamic viscosity coefficient 1.81×10 -5 Pa·s。
Structural dimensions and material selection for the comparative examples:
comparative example
An inner tube type Helmholtz resonance sound absorption structure without roughness is selected as a comparison example, wherein the diameter of a cavity is 20mm, the height of the cavity is 30mm, the diameter of an inner tube is 3mm, and the length of the inner tube is 25mm.
The structural dimensions and material selection of the embodiments:
example 1
The diameter of the cavity is 20mm, the height of the cavity is 30mm, the diameter of the petal-shaped inner insertion tube is 3mm, the relative roughness of the petal-shaped inner insertion tube is 0.15, the space wave number of the petal-shaped inner insertion tube is 4, and the length of the petal-shaped inner insertion tube is 25mm.
Example 2
The diameter of the cavity is 25mm, the height of the cavity is 40mm, the diameter of the petal-shaped inner insertion tube is 4mm, the relative roughness of the petal-shaped inner insertion tube is 0.2, the space wave number of the petal-shaped inner insertion tube is 6, and the length of the petal-shaped inner insertion tube is 30mm.
Example 3
The diameter of the cavity is 30mm, the height of the cavity is 50mm, the diameter of the petal-shaped inner insertion tube is 5mm, the relative roughness of the petal-shaped inner insertion tube is 0.25, the space wave number of the petal-shaped inner insertion tube is 8, and the length of the petal-shaped inner insertion tube is 40mm.
Referring to fig. 2, the helmholtz resonance phenomenon at low frequencies can achieve efficient sound absorption in a certain frequency range. By introducing radial roughness into the inner wall of the inner cannula, the acoustic impedance characteristic of the structure is improved, the acoustic impedance and the acoustic quality of the structure are enhanced, and the invention realizes perfect sound absorption of low frequency.
Referring to fig. 2, the comparative example reached a peak of sound absorption at 315Hz, the peak size was 0.94, and perfect sound absorption could not be achieved.
Example 1 has the same structural parameters as the comparative example, except that the inner wall of the inner cannula of example 1 has a radial roughness that achieves perfect sound absorption at 316Hz with a peak sound absorption of 0.99. Compared with the comparative example, after the radial roughness is introduced into the inner cannula, the sound absorption peak position of the invention is almost unchanged, and the sound absorption peak size is improved by 0.05 (5%). The sound absorption performance of the structure is greatly improved compared with that of the comparative example, and the sound absorption coefficient curve of the embodiment 1 is higher than that of the comparative example. The thickness of the structure is only 30mm, which is 1/36 of the corresponding perfect sound absorption wavelength, so the structure is a deep sub-wavelength scale low-frequency perfect sound absorption metamaterial;
example 2 after further optimization of the structural parameters, perfect sound absorption was achieved at 258Hz with a peak sound absorption of 0.99. Compared to the comparative example, the peak of the sound absorption of example 2 was shifted to a low frequency by 57Hz (18%), and the peak size of the sound absorption was increased by 0.05 (5%). The sound absorption properties of the structure are greatly improved compared to the comparative example. The thickness of the structure is only 40mm, which is 1/33 of the corresponding perfect sound absorption wavelength, so the structure is a deep sub-wavelength scale low-frequency perfect sound absorption metamaterial;
example 3 after further optimization of the structural parameters, perfect sound absorption was achieved at 204Hz with a peak sound absorption of 0.99. Compared to the comparative example, the sound absorption peak of example 3 was shifted to a low frequency by 111Hz (35%), and the sound absorption peak size was increased by 0.05 (5%). The sound absorption properties of the structure are greatly improved compared to the comparative example. The thickness of the structure is only 50mm, which is 1/34 of the corresponding perfect sound absorption wavelength, so the structure is a deep sub-wavelength scale low-frequency perfect sound absorption metamaterial;
the sound absorption coefficient curve shows that the invention can realize excellent low-frequency sound absorption performance in a certain frequency range, and the acoustic performance can be regulated by the design of different structural parameters.
The present invention has been described in terms of the preferred embodiments thereof, and it should be understood by those skilled in the art that various modifications can be made without departing from the principles of the invention, and such modifications should also be considered as being within the scope of the invention.
Claims (9)
1. The utility model provides a petal shape interpolation tubular helmholtz resonance sound absorption structure which characterized in that: the device comprises a cavity and a petal-shaped inner insertion tube, wherein the cavity is connected with the petal-shaped inner insertion tube through welding or cementing to form a petal-shaped inner insertion tube type Helmholtz resonance sound absorption structure; the upper surface of the cavity is provided with small holes, and the lower surface of the cavity is fixed on the surface of a wall body to be acoustically treated; the petal-shaped inner insertion tube is connected with the small hole on the cavity through welding or gluing, the radial roughness of the inner wall of the petal-shaped inner insertion tube is characterized by a function f=dX [0.5- δsin (nx) ], wherein d is the average diameter of the petal-shaped inner insertion tube, δ is the relative roughness of the petal-shaped inner insertion tube, n is the spatial wave number of the petal-shaped inner insertion tube, and x is the coordinate along the length direction of the petal-shaped inner insertion tube.
2. The petal-shaped inner tube type helmholtz resonance sound absorbing structure according to claim 1, characterized in that: the cavity is made of hard materials and comprises structural steel, resin, wood or composite materials.
3. The petal-shaped inner tube type helmholtz resonance sound absorbing structure according to claim 1, characterized in that: the diameter of the cavity is 20-30 mm, and the shape is cylindrical, cuboid, hexagonal prism or irregular.
4. The petal-shaped inner tube type helmholtz resonance sound absorbing structure according to claim 1, characterized in that: the height of the cavity is 30-50 mm.
5. The petal-shaped inner tube type helmholtz resonance sound absorbing structure according to claim 1, characterized in that: the petal-shaped inner insertion tube is made of hard materials, and comprises structural steel, resin, wood or composite materials.
6. The petal-shaped inner tube type helmholtz resonance sound absorbing structure according to claim 1, characterized in that: the average diameter of the petal-shaped inner cannula is 3-5 mm.
7. The petal-shaped inner tube type helmholtz resonance sound absorbing structure according to claim 1, characterized in that: the relative roughness of the petal-shaped inner cannula is 0.15-0.25 mm.
8. The petal-shaped inner tube type helmholtz resonance sound absorbing structure according to claim 1, characterized in that: the space wave number of the petal-shaped inner cannula is 4-8.
9. The petal-shaped inner tube type helmholtz resonance sound absorbing structure according to claim 1, characterized in that: the length of the petal-shaped inner cannula is 25-40 mm.
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN113362795A (en) * | 2021-05-10 | 2021-09-07 | 西安交通大学 | Porous sound absorbing structure of petal-shaped channel |
| CN113362793B (en) * | 2021-05-10 | 2024-05-24 | 西安交通大学 | Bidirectional rough parallel-arrangement micro-channel porous sound absorption structure |
| CN113362796B (en) * | 2021-05-10 | 2024-05-24 | 西安交通大学 | Bidirectional rough interpolation tube type Helmholtz resonance sound absorption structure |
| CN116189644B (en) * | 2023-04-28 | 2023-07-11 | 南京南大电子智慧型服务机器人研究院有限公司 | Broadband cylindrical acoustic wave absorber with sub-wavelength |
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| JP7172457B2 (en) * | 2018-11-05 | 2022-11-16 | ヤマハ株式会社 | Sound-absorbing units and sound-absorbing structures |
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