CN214796746U - Multi-frequency sound absorption type acoustic superstructure - Google Patents
Multi-frequency sound absorption type acoustic superstructure Download PDFInfo
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- CN214796746U CN214796746U CN202120681851.2U CN202120681851U CN214796746U CN 214796746 U CN214796746 U CN 214796746U CN 202120681851 U CN202120681851 U CN 202120681851U CN 214796746 U CN214796746 U CN 214796746U
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Abstract
The application relates to a multifrequency sound absorption type acoustics superstructure, including a plurality of sound absorption units that connect gradually, be provided with the cavity respectively in every sound absorption unit, be linked together through the trompil between the cavity in two adjacent sound absorption units to still be provided with the cavity intercommunication in first trompil and this sound absorption unit on first sound absorption unit. This application is through setting up a plurality of sound absorption units, and every sound absorption unit forms a helmholtz resonant cavity through setting up cavity and trompil, and every sound absorption unit is a helmholtz resonant cavity equivalently, and the cavity through making up a plurality of different units can produce the multiunit and absorb the peak, can reach nearly perfect sound absorption to the multiunit frequency, has promoted sound absorption noise reduction effect.
Description
Technical Field
The application relates to the technical field of acoustic materials, in particular to a multi-frequency sound absorption type acoustic superstructure.
Background
The absorption of sound has great significance in the aspects of indoor acoustics and environmental noise control, and the research and application of sound absorption are very diverse since the last century, the frequency range of human audible sound wave is 20Hz to 20000Hz, and the absorption, i.e. loss, of sound wave in air is usually very small, so that the loss of sound wave mainly occurs through the following mechanisms: in the viscous loss between the solid surface and the air, because the viscous boundary layer of the solid surface has no slip, a viscous layer exists on the solid interface, generally speaking, the larger the velocity gradient difference is, the larger the viscous loss is, so that the acoustic material is the most important in the noise reduction engineering, and the traditional acoustic material is divided into two parts: acoustically porous material and perforated sound absorbing structures.
The conventional materials have weak energy dissipation in the low frequency region, and if the conventional materials are used for absorbing the low frequency sound waves, a very thick structure (porous material) and a very deep back cavity (micro-perforated plate) are required, so that the conventional materials are not economical and occupy a large space, and the application range and application scene are limited.
Disclosure of Invention
In order to improve the sound absorption and noise reduction effect to the low frequency, the application provides a multifrequency sound absorption type acoustics superstructure.
The application provides a multifrequency sound absorption type acoustics superstructure adopts following technical scheme:
the utility model provides a multifrequency sound absorption type acoustics superstructure, includes a plurality of sound absorption units that connect gradually, is provided with the cavity respectively in every sound absorption unit, is linked together through the trompil between the cavity in two adjacent sound absorption units to still be provided with the cavity intercommunication in first trompil and this sound absorption unit on first sound absorption unit.
Through above-mentioned technical scheme, through setting up a plurality of sound absorption units, every sound absorption unit forms a Helmholtz resonant cavity through setting up cavity and trompil, and every sound absorption unit is a Helmholtz resonant cavity equivalently, can produce the multiunit through the cavity of making up a plurality of different units and absorb the peak, can reach nearly perfect sound absorption to the multiunit frequency, has promoted sound absorption noise reduction effect.
Optionally, a first insertion tube is disposed on the first opening, and the first insertion tube extends into the cavity in the first sound absorption unit.
Through the technical scheme, the first insertion pipe is arranged on the first opening, so that different Helmholtz resonant cavity resonant frequencies can be generated by changing the length of the first insertion pipe, and the setting for different noise frequencies is facilitated; meanwhile, the first insertion pipe is arranged to extend into the cavity of the first sound absorption unit, so that the space of the sound absorption unit can be saved.
Optionally, a cannula is disposed within the opening.
Through above-mentioned technical scheme, through set up the intubate in the trompil, just can produce different helmholtz resonant cavity resonant frequency through the length that changes the intubate, be convenient for set up to different noise frequency.
Optionally, the cavity is of a single-cavity or multi-cavity structure.
Through the technical scheme, the cavity is set to be of a single-cavity or multi-cavity structure, and almost perfect absorption of multiple groups of peak noises can be realized through accurate adjustment of the internal structure size of the multi-cavity under the condition that the overall size of each sound absorption is kept unchanged.
Optionally, the multi-cavity structure is a plurality of equally divided cavity structures.
Through the technical scheme, the multi-cavity structure is divided into the plurality of equally-divided cavities, so that the same sound absorption effect of each cavity can be guaranteed.
Optionally, the sound absorption units are arranged in a nested manner.
Through above-mentioned technical scheme, adopt the mode of setting that the cover inlayed with each sound absorption unit, be convenient for combine the sound absorption unit of each difference together, be convenient for realize the different peak noise of multiunit and absorb through changing different sound absorption units.
Optionally, a shared side wall structure is arranged between two adjacent sound absorption units, and the opening is arranged on the shared side wall.
Through the technical scheme, the two adjacent sound absorption units adopt the structure of the shared side wall, one cavity can be nested in the other cavity, and thus the assembly of each sound absorption unit is convenient.
Optionally, the cross section of the casing of each sound absorption unit is the same, and the casing is of a rectangular structure.
Through the technical scheme, the cross section of the shell of each sound absorption unit is set to be in a rectangular structure, so that the whole multi-frequency sound absorption type acoustic super junction forms a rectangular structure, and a plurality of multi-frequency sound absorption type acoustic super junctions are convenient to assemble and use.
Optionally, each sound absorption unit is made of a photosensitive resin material.
Through above-mentioned technical scheme, each sound absorption unit all adopts photosensitive resin material to make, and the mode of accessible vibration material disk makes carries out the production and makes, can realize the rapid prototyping to complicated structure.
In summary, the present application includes at least one of the following beneficial technical effects:
1. this application is through setting up a plurality of sound absorption units, and every sound absorption unit forms a helmholtz resonant cavity through setting up cavity and trompil, and every sound absorption unit is a helmholtz resonant cavity equivalently, and the cavity through making up a plurality of different units can produce the multiunit and absorb the peak, can reach nearly perfect sound absorption to the multiunit frequency, has promoted sound absorption noise reduction effect.
2. By arranging the cavity into a single-cavity or multi-cavity structure, the almost perfect absorption of multiple groups of peak noises can be realized by accurately adjusting the internal structure size of the multi-cavity under the condition of keeping the overall size of each sound absorption unchanged.
3. The sound absorption units are embedded in a sleeved mode, so that different sound absorption units are combined conveniently, and the absorption of different peak noises of multiple groups is realized by replacing different sound absorption units conveniently.
4. The cross section of the shell of each sound absorption unit is set to be a rectangular structure, so that the whole multi-frequency sound absorption type acoustic superstructure forms a rectangular structure, and a plurality of multi-frequency sound absorption type acoustic superstructures can be assembled and used conveniently.
Drawings
Fig. 1 is a schematic structural diagram of embodiment 1 of the present application.
Fig. 2 is a cross-sectional view of embodiment 1 of the present application.
Fig. 3 is a schematic structural view of a second sound absorbing unit embodied in an embodiment of the present application.
Fig. 4 is a graph of simulated sound absorption coefficients and experimental sound absorption coefficients of example 1 of the present application.
Fig. 5 is a schematic structural diagram of embodiment 2 of the present application.
Fig. 6 is a schematic structural view of a third sound absorbing unit embodied in embodiment 2 of the present application.
Fig. 7 is a schematic structural view of a fourth sound absorbing unit embodied in embodiment 2 of the present application.
Reference number, 1, a first sound absorption unit; 2. a second sound absorbing unit; 3. a third sound absorption unit; 4. a fourth sound absorbing unit; 101. a first opening; 102. a first cannula; 103. a first cavity; 201. a second opening; 202. a second cannula; 203. a second cavity; 301. a third opening; 302. a third cannula; 303. a third cavity; 401. a fourth opening; 402. a fourth cannula; 403. a fourth cavity; 5. a side wall.
Detailed Description
The present application is described in further detail below with reference to figures 1-7.
Example 1:
referring to fig. 1 and 2, the multi-frequency sound absorption type acoustic superstructure of the present embodiment includes two sound absorption units, a first sound absorption unit 1 and a second sound absorption unit 2, respectively, and the first sound absorption unit 1 and the second sound absorption unit 2 are both made of a photosensitive resin material, and in the present embodiment, the first sound absorption unit 1 and the second sound absorption unit 2 adopt a rectangular parallelepiped structure having a square cross section, a first cavity 103 with a square section is arranged in the first sound absorption unit 1, a first opening 101 is also arranged on the first sound absorption unit 1, the first opening 101 is communicated with the first cavity 103, a first insertion tube 102 is connected to the first opening 101, the first insertion tube 102 is formed integrally with the first opening 101, the first insertion tube 102 extends into the first cavity 103, the side of the first cavity 103 opposite to the first opening 101 is open and not closed.
Referring to fig. 2 and 3, the second sound absorbing unit 2 is a rectangular parallelepiped structure with a square cross section, a plurality of second cavities 203 with rectangular interfaces are arranged in the second sound absorbing unit 2, the second cavities 203 may be two, four or nine cavities, in this embodiment, nine second cavities 203 with square cross sections are used, and the second cavities 203 are closed cavities. The side wall 5 of the second sound absorption unit 2 is provided with 9 second openings 201, each second opening 201 corresponds to one second cavity 203, the second openings 201 are communicated with the second cavities 203, each second opening 201 is provided with one second insertion pipe 202, the second insertion pipes 202 extend into the second cavities 203, and the second insertion pipes 202 and the second cavities 203 are of an integrally formed structure.
When the second sound absorption unit 2 is connected with the first sound absorption unit 1, one side of the second sound absorption unit 2, which is provided with the second opening 201, is sleeved and embedded in the first cavity 103, so that the side wall 5 on the second sound absorption unit 2 seals the opening of the first cavity 103, that is, the first cavity 103 and the second cavity 203 share one side wall 5.
The embodiment further illustrates the noise reduction example of the transformer substation applied near the transformer substation, the transformer substation is often distributed in residential areas and factory residential areas, and the transformer substation generates noise during working and affects the lives of residents. Because the frequency of alternating current of a country or a region is fixed, the noise frequency distribution generated by the transformer substation presents multi-peak frequency multiplication distribution and is concentrated in a medium-low frequency band. Through the noise spectrum analysis of a certain type of transformer station, the noise of the transformer station is mainly concentrated around 100Hz and 400 Hz.
For safety, a partition wall is generally built around the transformer substation to be isolated from the surrounding environment, and on the basis of the prior art, a plurality of multi-frequency sound absorption type acoustic superstructures of the embodiment are assembled on the prior partition wall to form a new partition wall for sound absorption and noise reduction.
The multi-frequency sound absorption type acoustic superstructure of the present embodiment is designed based on the resonance principle of helmholtz resonant cavities, wherein the diameter and length of the aperture, and the diameter and length of the cavity are respectively denoted by D, l, D and T.
Helmholtz resonator resonance frequency frCan be calculated from equation (1), wherein,
is a constant number of times that the number of the first,
is the ratio of the diameter of the aperture to the diameter of the cavity,
is determined by l, d and T together.
The cross section of the cavity is a square with side length a and is expressed by a formula pi (D/2)2＝a2Equivalent transformation was performed. Formula (1) is suitable for calculating the resonance frequency of a single cavity, the approximate size of the structure can be determined according to the target frequency of noise reduction, and the structure needs to be further accurately adjusted in consideration of the coupling effect of the combined structure.
Referring to FIG. 2, specific structural parameters are labeled, where d1Denotes the diameter, l, of the first opening 1011Indicates the length of the first cannula 102, a1And T1Is the side length and height of the first cavity 103, where d2Denotes the diameter of the second opening 201, l2 denotes the length of the second cannula 202, a2And T2Is the side length and height of the second cavity 203. Considering the size limitation of a test sample of a standing wave tube in a laboratory, the length and the width of the combined structure are both 68mm, the total height is 100mm, and the wall thickness of the cavity is 1 mm.
In order to guide and optimize the design, reduce the design blindness and reduce the trial-manufacture cost, the acoustic simulation software is utilized to carry out a numerical model of a sound field on the combined structure, a size calculation result of a formula is taken as the initial size of the simulation model, the sound absorption frequency of the structure under the excitation action of the sound field is calculated, and further precise optimization is carried out on the structure parameters according to the target sound absorption frequency. Table 1 shows the optimized and adjusted dimensions of the structure.
TABLE 1 structural size (mm)
| T1 | T2 | d1 | d2 | l1 | l2 | a1 | a2 |
| 29 | 68 | 10 | 3 | 12 | 10 | 66 | 32 |
In order to further verify the effectiveness of numerical simulation optimization, according to the parameter optimization result, an experimental sample is prepared for testing the sound absorption coefficient in a laboratory.
The sound absorption coefficient of the material is measured by using an AWA6128A type standing wave tube tester, the tester is matched with computer test software, and the sound absorption coefficient of the material is automatically calculated according to a sound level of a peak point and a sound level of a valley point in the standing wave tube, which are measured by a test microphone, and a sound absorption coefficient calculation formula (2).
Where L is the difference between the peak and valley of the sound pressure level.
The simulated and experimental sound absorption coefficients of the composite structure are shown in fig. 4. The distribution of the simulated sound absorption coefficient on the surface of the result has good consistency with the distribution of the experimental sound absorption coefficient, and the maximum error of the positions of the two groups of absorption peaks is within 5 percent, thereby proving the effectiveness of the simulation model.
Example 2:
the multi-frequency sound absorption type acoustic superstructure of the present embodiment employs 3 sound absorption units, which can absorb and reduce noise for noise having three low frequencies.
Referring to fig. 5 and 6, the multi-frequency sound absorption-type acoustic superstructure of the present embodiment includes a first sound absorption unit 1, a third sound absorption unit 3, and a fourth sound absorption unit 4, and the first sound absorption unit 1, the third sound absorption unit 3, and the fourth sound absorption unit 4 are all made of a photosensitive resin material.
Referring to fig. 5 and 6, in the present embodiment, the first sound absorbing unit 1, the third sound absorbing unit 3, and the fourth sound absorbing unit 4 are of a rectangular parallelepiped structure with a square cross section, a first cavity 103 with a square cross section is disposed in the first sound absorbing unit 1, the first sound absorbing unit 1 is further provided with a first opening 101, the first opening 101 is communicated with the first cavity 103, the first opening 101 is connected with a first insertion tube 102, the first insertion tube 102 is integrally formed with the first opening 101, the first insertion tube 102 extends into the first cavity 103, and one side of the first cavity 103 opposite to the first opening 101 is of an open and non-closed structure.
Referring to fig. 5 and 6, a plurality of third cavities 303 with rectangular interfaces are arranged in the third sound absorbing unit 3, and the third cavities 303 may be two, four or nine equally divided cavities, in this embodiment, two third cavities 303 with rectangular cross sections are used. The side wall 5 of the third sound absorption unit 3 is provided with 2 third openings 301, each third opening 301 corresponds to a third cavity 303, the third openings 301 are communicated with the third cavities 303, each third opening 301 is provided with a third insertion tube 302, the third insertion tubes 302 extend into the third cavities 303, and the third insertion tubes 302 and the third cavities 303 are of an integrally formed structure. The side of the third cavity 303 opposite to the third opening 301 is in an open and unclosed structure.
When the third sound absorption unit 3 is connected with the first sound absorption unit 1, one side of the third sound absorption unit 3, which is provided with the third opening 301, is sleeved and embedded in the first cavity 103, so that the side wall 5 on the third sound absorption unit 3 seals the opening of the first cavity 103, that is, the first cavity 103 and the third cavity 303 share one side wall 5.
Referring to fig. 5 and 7, a plurality of equally divided fourth cavities 403 with rectangular interfaces are arranged in the fourth sound absorbing unit 4, the fourth cavities 303 may be two, four or nine equally divided cavities, in this embodiment, four fourth cavities 403 with square cross sections are adopted, and the fourth cavities 403 are closed cavities. A fourth opening 401 is formed in the side wall 5 of the fourth sound absorption unit 4, the number of the fourth opening 401 is 4, each fourth opening 401 corresponds to a fourth cavity 403, the fourth opening 401 is communicated with the fourth cavity 403, a fourth insertion tube 402 is arranged on each fourth opening 401, the fourth insertion tube 402 extends into the fourth cavity 403, and the fourth insertion tube 402 and the fourth cavity 403 are of an integrally formed structure.
When the fourth sound absorption unit 4 is connected to the third sound absorption unit 3, one side of the fourth sound absorption unit 4, which is provided with the fourth openings 401, is nested in the third cavity 303, specifically, every two fourth openings 401 correspond to one third cavity 303. The side wall 5 of the fourth sound-absorbing unit 4 thus blocks the opening of the third cavity 303, i.e. the third cavity 303 shares a side wall 5 with the fourth cavity 403.
The embodiments of the present invention are preferred embodiments of the present application, and the scope of protection of the present application is not limited by the embodiments, so: all equivalent changes made according to the structure, shape and principle of the present application shall be covered by the protection scope of the present application.
Claims (8)
1. A multifrequency sound absorption type acoustic superstructure, comprising: the sound absorption unit comprises a plurality of sound absorption units which are connected in sequence, wherein a cavity is arranged in each sound absorption unit, the cavities in two adjacent sound absorption units are communicated through an opening, and a first opening (101) is formed in the first sound absorption unit and communicated with the cavities in the sound absorption units.
2. The multi-frequency acoustic-absorption-type acoustic superstructure according to claim 1, characterized in that: a first inserting pipe (102) is arranged on the first opening (101), and the first inserting pipe (102) extends into a cavity in the first sound absorption unit.
3. The multi-frequency acoustic-absorption-type acoustic superstructure according to claim 1, characterized in that: and a cannula is arranged in the opening.
4. The multi-frequency acoustic-absorption-type acoustic superstructure according to claim 1, characterized in that: the cavity is of a single-cavity or multi-cavity structure.
5. The multi-frequency acoustic-absorption-type acoustic superstructure according to claim 4, characterized in that: the multi-cavity structure is a plurality of equally divided cavity structures.
6. The multi-frequency acoustic-absorption-type acoustic superstructure according to claim 1, characterized in that: the sound absorption units are arranged in a sleeved and embedded mode.
7. The multi-frequency acoustic-absorption-type acoustic superstructure according to claim 6, characterized in that: a shared side wall structure is arranged between two adjacent sound absorption units, and the opening is formed in the shared side wall.
8. The multi-frequency acoustic-absorption-type acoustic superstructure according to claim 1, characterized in that: the sections of the shells of the sound absorption units are the same and are all rectangular structures.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113846764A (en) * | 2021-11-29 | 2021-12-28 | 北京市科学技术研究院城市安全与环境科学研究所 | Separate perforation type square tube space sound absorber |
| CN115013120A (en) * | 2022-06-22 | 2022-09-06 | 广州美的华凌冰箱有限公司 | Silencer |
-
2021
- 2021-04-02 CN CN202120681851.2U patent/CN214796746U/en active Active
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113846764A (en) * | 2021-11-29 | 2021-12-28 | 北京市科学技术研究院城市安全与环境科学研究所 | Separate perforation type square tube space sound absorber |
| CN115013120A (en) * | 2022-06-22 | 2022-09-06 | 广州美的华凌冰箱有限公司 | Silencer |
| CN115013120B (en) * | 2022-06-22 | 2023-07-14 | 广州美的华凌冰箱有限公司 | Muffler |
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