CN219303324U

CN219303324U - Additional periodic multimode coupling regulation elastic cavity sound absorption metamaterial pipeline structure

Info

Publication number: CN219303324U
Application number: CN202320043849.1U
Authority: CN
Inventors: 王婷; 刘俊怡; 张靖宇; 董文凯; 陈美霞; 崔华畅
Original assignee: Huazhong University of Science and Technology
Current assignee: Huazhong University of Science and Technology
Priority date: 2023-01-06
Filing date: 2023-01-06
Publication date: 2023-07-04
Anticipated expiration: 2033-01-06

Abstract

The utility model discloses an additional period multimode coupling regulation elastic cavity sound absorption metamaterial pipeline structure which comprises a special-shaped Helmholtz resonant cavity periodically arranged on the outer wall of a pipeline, wherein the special-shaped Helmholtz resonant cavity is cuboid, a first thin plate is arranged at the top, a second thin plate is arranged between the top and the bottom, the first thin plate and the second thin plate are parallel to each other, and the bottom is communicated with the outer wall of the pipeline through an opening. The utility model can realize attenuation of sound wave energy of a plurality of frequency points. The sound absorption metamaterial pipeline structure provided by the utility model is particularly suitable for absorbing sound waves in a low-frequency range, and is beneficial to the fact that the elastic thin plate has rich modes and the mode coupling of the elastic thin plate and the sound cavity.

Description

Additional periodic multimode coupling regulation elastic cavity sound absorption metamaterial pipeline structure

Technical Field

The utility model belongs to the technical field of acoustic metamaterial, and particularly relates to an additional period multimode coupling regulation elastic cavity sound absorption metamaterial pipeline structure.

Background

Noise is ubiquitous in production and life, and can affect the performance and use of equipment, and also cause noise pollution to endanger the physical and mental health of human beings. Because sound waves in the low frequency range have a strong penetrating power and dissipate slowly during propagation, they are difficult to control. Therefore, control research of low frequency noise and vibration has been a problem for the scholars to keep alive.

Pipeline systems are very common in ship hulls, so being able to design an acoustic pipeline with good sound absorption properties is of great importance for noise control. Helmholtz resonators have simple, adjustable features and are often used in various ductwork noise control processes. The conventional helmholtz resonator consists of a cavity and a short pipe connected with each other, and the resonance frequency of the conventional helmholtz resonator is usually only determined by the geometric dimension of the conventional helmholtz resonator, and can be directly calculated after simplification, and the sound absorption effect of the conventional helmholtz resonator is the best at the resonance frequency.

However, the helmholtz resonant cavity formed by connecting one cavity with one short tube has limited absorption effect on sound waves in a low frequency range, and how to realize effective absorption of the low frequency sound waves is a technical problem to be solved at present.

Disclosure of Invention

Aiming at the defects or improvement demands of the prior art, the utility model provides an additional periodic multimode coupling regulation elastic cavity sound absorption metamaterial pipeline structure, and aims to improve and optimize the pipeline structure, so that the technical problem of poor absorption effect of low-frequency sound waves is solved.

In order to achieve the above object, according to one aspect of the present utility model, there is provided an additional periodic multimode coupling regulation elastic cavity sound absorption metamaterial pipeline structure, including a profiled helmholtz resonator periodically arranged on an outer wall of a pipeline, the profiled helmholtz resonator being of a cuboid type, a first thin plate being arranged at a top, a second thin plate being arranged between the top and the bottom, the first thin plate being parallel to the second thin plate, the bottom being communicated with the outer wall of the pipeline through an opening.

Preferably, the first sheet and the second sheet are aluminum plates, and the side wall and the bottom material of the abnormal shape helmholtz resonance cavity are organic glass.

Preferably, the material of the abnormal shape helmholtz resonator is an aluminum plate.

Preferably, the mass is arranged in a central position of the first sheet and/or the second sheet.

Preferably, the number of the mass blocks is at least two, and the mass blocks are uniformly distributed on the first thin plate and/or the second thin plate.

Preferably, the opening is square.

Preferably, the cross section of the pipeline is rectangular.

Preferably, the number of the abnormal Helmholtz resonant cavities is 5-8.

In general, the above technical solutions conceived by the present utility model can achieve at least the following advantageous effects compared to the prior art.

(1) According to the utility model, the second thin plate is arranged between the top and the bottom, the second thin plate, the first thin plate and the inner wall of the abnormal-shaped Helmholtz resonant cavity form a closed cavity, the first thin plate, the second thin plate and the inner wall of the Helmholtz resonant cavity form a closed cavity, after sound waves enter from the neck opening of the abnormal-shaped Helmholtz resonant cavity, the fluid in the cavity and the elastic thin plate are caused to resonate, the elastic thin plate has rich modes, and the modes of the thin plate and the acoustic cavity are coupled, so that attenuation of sound wave energy of a plurality of frequency points is realized. The sound absorption metamaterial pipeline structure provided by the utility model is particularly suitable for absorbing sound waves in a low-frequency range, and is beneficial to the fact that the elastic thin plate has rich modes and the mode coupling of the elastic thin plate and the sound cavity.

(2) In the utility model, the first sheet and the second sheet adopt aluminum plates, and the density and the rigidity of the aluminum plates are lower, namely the resonance frequency is lower, so that resonance is easier to occur at low frequency, namely the sound absorption effect at lower frequency is realized.

(3) The utility model can further adopt to add the mass block on the second thin plate or simultaneously add the mass block on the first thin plate and the second thin plate, thereby realizing lower-frequency sound absorption and better sound absorption effect.

(4) According to the utility model, the rigid inner wall of the cavity can be further replaced by an aluminum plate, so that richer modes are realized, and a better sound absorption effect is achieved.

(5) According to the utility model, sound wave absorption of different frequencies can be realized by changing the number of the abnormal Helmholtz resonant cavities and the size of the abnormal Helmholtz resonant cavities, so that the universality is good.

Drawings

FIG. 1 is a front view of an additional periodic multimode coupling regulated elastic cavity sound absorbing metamaterial pipeline structure provided by the utility model;

FIG. 2 is a perspective view of an additional periodic multimode coupling regulated elastic cavity sound absorbing metamaterial pipeline structure provided by the utility model;

FIG. 3 is a front view of the structure of the additional periodic multimode coupling regulated elastic cavity sound absorbing metamaterial pipeline provided by the utility model;

FIG. 4 is the piping loss of a single profiled Helmholtz resonator provided in example 1 of the present utility model;

FIG. 5 is the piping loss for 5 profiled Helmholtz resonator cavities provided in example 2 of the present utility model;

FIG. 6 is the piping loss for 6 profiled Helmholtz resonator cavities provided in example 3 of the present utility model;

FIG. 7 is the piping loss for 8 profiled Helmholtz resonator cavities provided in example 4 of the present utility model;

FIG. 8 is the piping loss for a 1 profiled Helmholtz resonator provided in example 5 of the present utility model;

FIG. 9 is the piping loss for a 1 profiled Helmholtz resonator provided in example 6 of the present utility model;

FIG. 10 is the piping loss for a 1 profiled Helmholtz resonator provided in example 7 of the present utility model;

FIG. 11 is the piping loss for a 1 profiled Helmholtz resonator provided in example 8 of the present utility model;

fig. 12 is the piping loss for a 1 profiled helmholtz resonator provided in comparative example 1 of the present utility model.

Detailed Description

The present utility model will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present utility model more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the utility model. In addition, the technical features of the embodiments of the present utility model described below may be combined with each other as long as they do not collide with each other.

The utility model provides an additional periodic multimode coupling regulation elastic cavity sound absorption metamaterial pipeline structure which comprises a special-shaped Helmholtz resonant cavity 2 periodically arranged on the outer wall of a pipeline 1, wherein the special-shaped Helmholtz resonant cavity 2 is of a cuboid shape, the top of the special-shaped Helmholtz resonant cavity is a first thin plate 3, a second thin plate 4 is arranged between the top and the bottom, the first thin plate 3 is parallel to the second thin plate 4, and the bottom of the special-shaped Helmholtz resonant cavity is communicated with the outer wall of the pipeline through an opening 5.

In a possible manner, the first sheet 3 and the second sheet 4 are aluminum sheets, and the side wall and the bottom material of the profiled helmholtz resonator 2 are plexiglas.

In one possible way, the material of the profiled helmholtz resonator body 2 is an aluminium plate.

In one possible way, the mass is arranged in a central position of the first sheet 3 and/or of the second sheet 4.

In one possible way, the number of the masses is at least two, and the masses are uniformly distributed on the first sheet 3 and/or the second sheet 4.

Wherein the opening 5 is square. The section of the pipeline 1 is rectangular.

In a possible manner, the number of the abnormal-shaped helmholtz resonator cavities 2 is 5 to 8.

The following are specific examples:

example 1

The embodiment provides a sound absorption metamaterial pipeline structure for low frequency, multifrequency, broadband, including the abnormal shape helmholtz resonance cavity of periodic arrangement on the pipeline outer wall, abnormal shape helmholtz resonance cavity is cuboid type, and the top is first sheet metal, sets up the second sheet metal between top and bottom, first sheet metal and second sheet metal are parallel to each other, the bottom with the pipeline outer wall passes through neck opening intercommunication, the pipeline cross-section is square, first sheet metal with the second sheet metal is aluminum plate, and the rest part material of abnormal shape helmholtz resonance cavity is organic glass.

In this embodiment, the number of abnormal helmholtz resonator cavities is 5.

The specific parameters of which are shown below,

example 2

The present embodiment differs from embodiment 1 in that the number of profiled helmholtz resonator cavities is 5.

Example 3

The present embodiment differs from embodiment 1 in that the number of profiled helmholtz resonator cavities is 6.

Example 4

The present embodiment differs from embodiment 1 in that the number of profiled helmholtz resonator cavities is 8.

Example 5

The present example differs from example 1 in that a spot mass of 0.05kg was placed in the very middle of the second sheet.

Example 6

The present embodiment differs from embodiment 1 in that a dot mass of 0.05kg is provided simultaneously between the first sheet and the second sheet.

Example 7

The difference between this embodiment and embodiment 1 is that the distance between the first sheet and the second sheet is different, 0.067m, i.e. the second sheet is located 1/3 of the lower surface of the cavity.

Example 8

The present embodiment differs from embodiment 1 in that the thickness of the first sheet and the second sheet are different, and both are 0.003m at the same time.

Comparative example 1

The present comparative example is different from example 1 in that the materials of the first sheet and the second sheet are steel.

Results and discussion:

the sound transmission loss calculations were performed on the sound absorption metamaterial pipe structures prepared in examples 1 to 8 and comparative example 1, respectively. The results are shown in FIGS. 4-12.

Referring to fig. 4-12, it can be seen that the sound absorption metamaterial pipeline structure provided by the utility model has a plurality of sound absorption peaks at low frequency, and can realize pipeline sound absorption at low frequency and wide frequency. Under the condition that parameters such as the size of the abnormal shape helmholtz resonance cavity are the same, the quantity of the abnormal shape helmholtz resonance cavity is changed, and the influence on the sound absorption effect is achieved.

Referring to fig. 8-11, it can be seen that, after the mass is added, the frequency corresponding to the peak of sound absorption changes, and the peak of sound absorption changes in size.

Referring to fig. 12, which is a calculation result of sound transmission loss of comparative example 1, when the materials of the first and second thin plates in the sound absorption metamaterial pipe structure are steel, and the materials of the first and second thin plates are identical to those of the rest, since the density and rigidity of the steel plate are both greater than those of the aluminum plate, and the resonance frequency of the steel plate is higher than that of the aluminum plate, the low frequency sound absorption effect of the embedded steel plate in the sound absorption metamaterial pipe structure is far less than that of the embedded aluminum plate.

It will be readily appreciated by those skilled in the art that the foregoing description is merely a preferred embodiment of the utility model and is not intended to limit the utility model, but any modifications, equivalents, improvements or alternatives falling within the spirit and principles of the utility model are intended to be included within the scope of the utility model.

Claims

1. An additional periodic multimode coupling regulation elastic cavity sound absorption metamaterial pipeline structure is characterized by comprising a special-shaped Helmholtz resonant cavity (2) periodically arranged on the outer wall of a pipeline (1),

the abnormal shape helmholtz resonance cavity (2) is cuboid, and the top is first sheet metal (3), sets up second sheet metal (4) between top and bottom, and first sheet metal (3) are parallel to each other with second sheet metal (4), the bottom with pipeline outer wall passes through opening (5) intercommunication.

2. The sound absorption metamaterial pipeline structure as claimed in claim 1, wherein the first sheet (3) and the second sheet (4) are aluminum plates, and the side wall and the bottom material of the abnormal-shaped helmholtz resonator (2) are plexiglas.

3. Sound absorbing metamaterial pipeline structure as claimed in claim 1, wherein the profiled helmholtz resonator (2) is made of aluminium.

4. Sound absorbing metamaterial pipe structure as claimed in claim 1, wherein the mass is arranged in a central position of the first sheet (3) and/or the second sheet (4).

5. The sound absorbing metamaterial pipeline structure as claimed in claim 4, wherein the number of the mass blocks is at least two, and the mass blocks are uniformly distributed on the first sheet (3) and/or the second sheet (4).

6. Sound absorbing metamaterial pipe structure as claimed in claim 1, wherein the openings (5) are square.

7. The sound absorbing metamaterial pipe structure as claimed in claim 1, wherein the pipe (1) is rectangular in cross section.

8. The sound absorption metamaterial pipeline structure as claimed in claim 1 or 2, wherein the number of the abnormal-shaped helmholtz resonator cavities (2) is 5-8.