CN111696507B - Underwater sound absorption inner insertion tube type Helmholtz resonance cavity structure modified by damping layer - Google Patents
Underwater sound absorption inner insertion tube type Helmholtz resonance cavity structure modified by damping layer Download PDFInfo
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- CN111696507B CN111696507B CN202010486467.7A CN202010486467A CN111696507B CN 111696507 B CN111696507 B CN 111696507B CN 202010486467 A CN202010486467 A CN 202010486467A CN 111696507 B CN111696507 B CN 111696507B
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- sound absorption
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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
Abstract
The invention discloses an underwater sound absorption inner intubation type Helmholtz resonance cavity structure modified by a damping layer. The invention has excellent low-frequency sound absorption performance, good bearing performance and light weight performance. Have more adjustable structural parameters in the aspect of the design, can carry out corresponding regulation according to the operating condition demand, simple structure easily makes.
Description
Technical Field
The invention belongs to the technical field of acoustic metamaterials, and particularly relates to an underwater sound absorption inner insertion tube type Helmholtz resonance cavity structure modified by a damping layer.
Background
The acoustic metamaterial is an artificial periodic composite structure, and has the unconventional acoustic characteristics different from natural materials, such as acoustic focusing, negative refraction, unidirectional transmission, acoustic stealth and the like. In addition, the perfect absorption of low-frequency sound waves by the deep sub-wavelength scale structure is also one of the important special properties of the acoustic metamaterial. In aeroacoustics, perfect absorption based on the helmholtz resonance principle can be achieved by a structural design of space winding or hierarchical perforation. Some of these structures also exhibit broadband absorption capability through the parallel connection of multiple elements having different geometric parameters.
But in water acoustics, metamaterials relying on viscous energy dissipation of air would no longer be suitable due to the approximate incompressibility and relatively small viscosity of water. Furthermore, the wavelength of sound waves in water is 4 times or more that of air at the same frequency, which makes it more difficult to achieve complete absorption of low frequencies by a small-sized structure.
In the traditional underwater sound absorption material/structure, for example, materials/structures such as a sound absorption covering layer with periodically arranged cavities, a local resonance type phononic crystal, an impedance gradual change type sound absorption covering layer and the like, most of matrixes of the traditional underwater sound absorption material/structure are made of rubber or polyurethane, and the traditional underwater sound absorption material/structure needs to be adhered to a steel shell of underwater equipment during actual work, so that the structural weight is increased, the bearing performance is poor, and the traditional underwater sound absorption material/structure is easy to deform under the action of deep water load, so that the sound absorption performance is weakened. In summary, the above structure generally has the problems of poor low-frequency sound absorption performance, heavier mass and poor bearing performance.
Disclosure of Invention
The invention aims to solve the technical problems in the prior art, and provides an underwater sound absorption inner intubation type Helmholtz resonance cavity structure modified by a damping layer, which solves the problems of poor low-frequency sound absorption performance, heavy weight and poor bearing performance of the traditional underwater sound absorption structure.
The invention adopts the following technical scheme:
the utility model provides an underwater sound absorption intubate formula helmholtz resonance cavity structure that damping layer was decorated, includes the cavity, and the inner wall of cavity is provided with the damping inner liner, and the one end center of cavity is opened porosely, downtheholely is provided with the intubate, and the other end is equipped with under water and is connected, and intubate and cavity welding or the mode of gluing are connected and are constituted underwater sound absorption intubate formula helmholtz resonance cavity structure that damping layer was decorated.
Specifically, the height of the cavity is 30-50 mm, and the length of the inner insertion tube is 25-35 mm.
Specifically, the cavity is cylindrical, cuboid, hexagonal prism or irregular and is made of structural steel.
Specifically, the diameter of the cavity is 32-50 mm.
Specifically, the diameter of the inner insertion tube is 2.5-4 mm.
Specifically, the thickness of the damping lining layer is 2-4 mm.
Specifically, the damping lining layer is made of a viscoelastic material.
Further, the thickness of the cavity is 1/333-1/104 of the corresponding perfect sound absorption wavelength.
Compared with the prior art, the invention has at least the following beneficial effects:
the underwater sound absorption inner insertion tube type Helmholtz resonance cavity structure modified by the damping layer is characterized in that the inner insertion tube is connected with an opening on the cavity through welding or adhesive bonding, the inner part of the cavity is communicated with the outside through the inner insertion tube, water flows into the cavity unit through the inner insertion tube to form a Helmholtz resonance cavity, and the wall surface of the resonance cavity is pasted with the damping lining layer, so that the acoustic impedance characteristic of the structure is improved, and the low-frequency sound absorption performance of the structure is improved. Under the premise of realizing good low-frequency underwater sound absorption performance, the steel cavity structure reduces the structure weight, ensures the structure bearing performance, and solves the problems of poor low-frequency sound absorption performance, heavier mass and poor bearing performance of the traditional underwater sound absorption structure.
Furthermore, the height of the cavity is 30-50 mm, the height of the cavity determines the size of the resonant cavity, the sound absorption frequency band of the structure can be adjusted by changing the height of the cavity, the length of the inner inserting tube is 25-35 mm, the length of the inner inserting tube determines the height of a water column in a perforation, and the resonant sound absorption characteristic of the structure is controlled.
Furthermore, the cavity is made of structural steel and is in a cylindrical shape, a rectangular parallelepiped shape, a hexagonal prism shape or an irregular shape, the side wall of the cavity is used for bearing compression load, a small hole is formed in the upper surface of the cavity, the lower surface of the cavity is fixed on underwater equipment needing acoustic treatment, and the application of the structural steel enables the structure to have good bearing performance.
Furthermore, the diameter of the cavity is 32-50 mm, the cavity is used as a Helmholtz resonant cavity to play a role in sound capacity, and the peak sound absorption frequency of the structure can be controlled by adjusting the diameter of the cavity.
Furthermore, the diameter of the inner inserting tube is 2.5-4 mm, the diameter of the inner inserting tube determines the diameter of a water column in the tube, and the Helmholtz resonance characteristic of the structure can be changed by adjusting the diameter of the inner inserting tube, so that the sound absorption performance of the structure is adjusted.
Furthermore, the thickness of the damping lining layer is 2-4 mm, the thickness of the damping lining layer determines the size of additionally increased acoustic resistance and acoustic capacitance, the acoustic impedance characteristic of the structure can be influenced, and the excellent sound absorption effect of specific frequency can be realized through reasonable design.
Further, the damping inner liner layer is made by sticky elastic materials such as rubber or polyurethane, pastes on the cavity inner wall, and pasting of damping inner liner layer provides extra acoustic resistance and sound capacity for helmholtz resonance chamber, has improved the impedance characteristic of structure, is favorable to realizing the low frequency of structure and absorbs sound under water.
In conclusion, the sound-absorbing material has excellent low-frequency sound-absorbing performance, good bearing performance and light weight. Have more adjustable structural parameters in the aspect of the design, can carry out corresponding regulation according to the operating condition demand, simple structure easily makes.
The technical solution of the present invention is further described in detail by the accompanying drawings and embodiments.
Drawings
FIG. 1 is a schematic structural view of the present invention, wherein (a) is a perspective view and (b) is a sectional view;
FIG. 2 is a graphical representation of the sound absorption coefficient within 0 to 500Hz for three embodiments of the present invention.
Wherein: 1. a cavity; 2. inserting a tube; 3. a damping liner layer.
Detailed Description
In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "one side", "one end", "one side", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplicity of description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed in a particular orientation, and be operated, and thus, are not to be construed as limiting the present invention. In addition, in the description of the present invention, "a plurality" means two or more unless otherwise specified.
In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.
Various structural schematics according to the disclosed embodiments of the invention are shown in the drawings. The figures are not drawn to scale, wherein certain details are exaggerated and possibly omitted for clarity of presentation. The shapes of the various regions, layers and their relative sizes, positional relationships are shown in the drawings as examples only, and in practice deviations due to manufacturing tolerances or technical limitations are possible, and a person skilled in the art may additionally design regions/layers with different shapes, sizes, relative positions, according to the actual needs.
The invention provides an underwater sound absorption inner intubation type Helmholtz resonance cavity structure modified by a damping layer, wherein a Helmholtz resonance cavity is formed by welding or gluing a cavity 1 and an inner intubation 2, and a damping lining layer 3 is adhered to the wall surface of the resonance cavity, so that the acoustic impedance characteristic of the structure is improved, and the low-frequency sound absorption performance of the structure is improved. Under the prerequisite that realizes good low frequency sound absorption performance under water of steel cavity structure, alleviateed structural weight, guaranteed structure bearing capacity, solved traditional sound absorption structure under water in ubiquitous low frequency sound absorption performance not good, the quality heavier, the bearing capacity poor problem.
Referring to fig. 1, the underwater sound absorption inner insertion tube type helmholtz resonance cavity structure modified by the damping layer of the present invention includes a cavity 1, an inner insertion tube 2 and a damping liner layer 3, wherein the damping liner layer 3 is adhered to an inner wall of the cavity 1, and the inner insertion tube 2 is sleeved in the cavity 1 and connected by welding or gluing to form the underwater sound absorption inner insertion tube type helmholtz resonance cavity structure modified by the damping layer.
The cavity 1 is made of structural steel, the upper surface of the cavity is provided with a small hole, the lower surface of the cavity is fixed on underwater equipment needing acoustic treatment, the diameter of the cavity 1 is 32-50 mm, the cavity is cylindrical, rectangular, hexagonal prism or irregular, and the height of the cavity 1 is 30-50 mm.
The inner inserting tube 2 is made of structural steel and is connected with an opening on the cavity through welding or adhesive bonding, the length of the inner inserting tube 2 is 25-35 mm, and the diameter of the inner inserting tube 2 is 2.5-4 mm.
The damping lining layer 3 is made of rubber or polyurethane and other viscous elastic materials and is adhered to the inner wall of the cavity 1, and the thickness of the damping lining layer 3 is 2 mm-4 mm.
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, 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 present invention, 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 derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The sound absorption performance of the acoustic resonator is mainly determined by resonance cavity parameters, and specifically comprises the determination of cavity diameter, cavity height, inner insertion tube diameter, inner insertion tube length and damping lining layer thickness. The bearing and light weight performance is mainly determined by the size of the cavity, including the diameter of the cavity, the height of the cavity and the like. Because the structural parameters are adjustable parameters, the corresponding performance requirements of sound absorption, bearing and light weight can be realized through adjustment. The technical solution of the present invention is exemplarily illustrated by the following specific examples.
Materials for examples:
structural steel: it is characterized by a density of 7850kg/m 3 Young's modulus 200GPa, poisson's ratio 0.2.
Rubber: it is characterized by a density of 1100kg/m 3 Young's modulus 10MPa, poisson's ratio 0.49, and equivalent isotropic loss factor 0.3.
Water: it is characterized by a density of 1000kg/m 3 The sound velocity is 1500m/s, and the dynamic viscosity coefficient is 0.00101 Pa.s.
Structural dimensions and material selection of the examples:
example 1
The diameter of the cavity is 32mm, the height of the cavity is 30mm, the diameter of the inner inserting tube is 3mm, the length of the inner inserting tube is 25mm, and the thickness of the damping lining layer is 2mm.
Example 2
The diameter of the cavity is 50mm, the height of the cavity is 40mm, the diameter of the inner inserting tube is 4mm, the length of the inner inserting tube is 30mm, and the thickness of the damping lining layer is 4mm.
Example 3
The diameter of the cavity is 40mm, the height of the cavity is 50mm, the diameter of the inner inserting tube is 2.5mm, the length of the inner inserting tube is 35mm, and the thickness of the damping lining layer is 3mm.
Referring to fig. 2, the helmholtz resonance phenomenon at low frequencies can achieve perfect sound absorption in a certain frequency range. The damping lining layer is adhered to the inner wall of the resonant cavity, so that the acoustic impedance characteristic of the structure is improved, the rubber layer provides extra acoustic resistance and acoustic capacity, and Helmholtz-like resonance is formed, so that underwater low-frequency perfect sound absorption is realized.
Referring to fig. 2, in example 1, the sound absorption coefficient at 125-180 Hz is greater than 0.5, the half sound absorption bandwidth is 37%, perfect sound absorption is achieved at 150Hz, the peak value of the sound absorption coefficient is 0.99, perfect absorption of low-frequency sound waves is realized, the structure thickness is only 55mm at this time, which is 1/333 of the corresponding perfect sound absorption wavelength, and thus the structure is a deep sub-wavelength scale low-frequency perfect sound absorption metamaterial;
in the embodiment 2, the sound absorption coefficient at 170-255 Hz is greater than 0.5, the half sound absorption bandwidth is 40%, perfect sound absorption is achieved at 210Hz, the peak value of the sound absorption coefficient is 0.99, perfect absorption of low-frequency sound waves is realized, the structure thickness is only 50mm at the moment and is 1/143 of the corresponding perfect sound absorption wavelength, and therefore the structure is a deep sub-wavelength scale low-frequency perfect sound absorption metamaterial;
in the embodiment 3, the sound absorption coefficient at 290-430 Hz is more than 0.5, the half sound absorption bandwidth is 38%, perfect sound absorption is achieved at 360Hz, the peak value of the sound absorption coefficient is 0.99, perfect absorption of low-frequency sound waves is realized, the structure thickness is only 40mm at the moment and is 1/104 of the corresponding perfect sound absorption wavelength, and therefore, the structure is a deep sub-wavelength 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 adjustment of the acoustic performance can be realized through the design of different structural parameters.
The invention achieves the technical effects that:
1. has excellent low-frequency sound absorption performance. The sound absorption coefficient of the test piece can reach more than 0.5 and the half sound absorption bandwidth can reach more than 35 percent within a certain range of 0-500 Hz. The sound absorption peak value of partial position can reach more than 0.99, perfect sound absorption is realized, the thickness is only 1/333-1/104 of the corresponding perfect sound absorption wavelength, and the super-material is a deep sub-wavelength scale underwater low-frequency perfect sound absorption super-material.
2. Has good bearing performance and light weight performance. The cavity is made of structural steel, and the structure has good pressure resistance and is a multifunctional structure with bearing and light weight.
3. With more adjustable parameters and variables. The diameter of the cavity, the height of the cavity, the diameter of the inner inserting tube, the length of the inner inserting tube, the thickness of the damping lining layer and the like are all adjustable parameters, and can be selected and adjusted reasonably according to specific use scenes, such as the requirement on the bearing performance or the requirement on the acoustic performance.
4. Simple structure and easy manufacture.
The above-mentioned contents are only for illustrating the technical idea of the present invention, and the protection scope of the present invention is not limited thereby, and any modification made on the basis of the technical idea of the present invention falls within the protection scope of the claims of the present invention.
Claims (3)
1. The underwater sound absorption inner intubation type Helmholtz resonance cavity structure modified by the damping layer is characterized by comprising a cavity (1) with the height of 30 to 50mm, the diameter of the cavity (1) is 32 to 50mm, a damping lining layer (3) with the thickness of 2 to 4mm is arranged on the inner wall of the cavity (1), a hole is formed in the center of one end of the cavity (1), an inner intubation tube (2) with the length of 25 to 35mm and the diameter of 2.5 to 4mm is arranged in the hole, the other end of the cavity is connected with underwater equipment, the inner intubation tube (2) and the cavity (1) are connected in a welding or gluing mode to form the underwater sound absorption inner intubation type Helmholtz resonance cavity structure modified by the damping layer, and the thickness of the cavity (1) is 1/333 to 1/104 of the corresponding perfect sound absorption wavelength.
2. The underwater sound-absorbing intubation type helmholtz resonance cavity structure modified by the damping layer according to claim 1, wherein the shape of the cavity (1) is cylindrical, rectangular, hexagonal prism or irregular, and is made of structural steel.
3. The underwater sound absorption inner intubation type Helmholtz resonance cavity structure modified by the damping layer as claimed in claim 1, wherein the damping lining layer (3) is made of viscoelastic material.
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| CN112669802A (en) * | 2020-12-11 | 2021-04-16 | 南京光声超构材料研究院有限公司 | Sound absorption structure and sound absorption device |
| CN113362796A (en) * | 2021-05-10 | 2021-09-07 | 西安交通大学 | Two-way rough inner insertion tube type Helmholtz resonance sound absorption structure |
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| CN103533488A (en) * | 2013-10-09 | 2014-01-22 | 清华大学 | Helmholtz resonator and design method thereof |
| CN109346051A (en) * | 2018-12-13 | 2019-02-15 | 西安交通大学 | Built-in perforated-plate Helmholtz resonator and broad band low frequency sound absorption structure based on it |
| WO2019182213A1 (en) * | 2018-03-19 | 2019-09-26 | 한국과학기술원 | Sound absorption device |
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| CN103533488A (en) * | 2013-10-09 | 2014-01-22 | 清华大学 | Helmholtz resonator and design method thereof |
| WO2019182213A1 (en) * | 2018-03-19 | 2019-09-26 | 한국과학기술원 | Sound absorption device |
| CN109346051A (en) * | 2018-12-13 | 2019-02-15 | 西安交通大学 | Built-in perforated-plate Helmholtz resonator and broad band low frequency sound absorption structure based on it |
| CN111105774A (en) * | 2019-10-29 | 2020-05-05 | 同济大学 | Helmholtz resonator and low-frequency broadband sound absorption and noise reduction structure based on same |
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