Noise reduction brick based on sound absorption metamaterial

Abstract

The invention discloses a noise reduction brick based on a sound absorption metamaterial, and relates to the technical field of indoor noise control, the noise reduction brick comprises a plurality of noise reduction units, the plurality of noise reduction units are sleeved in sequence, a sound absorption distance exists between the adjacent noise reduction units, the side wall of each noise reduction unit is provided with a plurality of openings, and the openings are communicated with the sound absorption metamaterial. The openings in every two adjacent noise reduction units are arranged in a staggered mode, and the noise reduction units are made of sound absorption materials. The sound absorption strength and the pressure bearing capacity can be improved.

Description

Technical Field

[0001] The invention relates to the technical field of indoor noise prevention and control, and in particular to a noise reduction brick based on sound-absorbing metamaterial. Background Art

[0002] Existing indoor vibration and noise reduction methods include using porous sponges, fine-groove sound-absorbing panels, etc. to reduce noise. The noise reduction principle is that when sound waves encounter porous shapes or groove structures, the sound wave energy is dissipated due to viscosity, thereby reducing the sound intensity.

[0003] Existing materials such as porous sound-absorbing sponges are often pasted on the wall to achieve noise reduction effects, but they have the disadvantages of poor sound absorption effects on low-frequency noise and poor fire and moisture resistance. Fine groove sound-absorbing panels are fixed on the ceiling to achieve noise reduction effects, but they have the disadvantages of being easy to fall off. Summary of the invention

[0004] The purpose of the present invention is to provide a noise reduction brick based on sound-absorbing metamaterials to solve the problems existing in the above-mentioned prior art and improve the sound absorption intensity and pressure-bearing capacity.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] The present invention provides a noise reduction brick based on sound-absorbing metamaterial, comprising a plurality of noise reduction units, wherein the plurality of noise reduction units are arranged in sequence, and there is a sound-absorbing spacing between adjacent noise reduction units, and a plurality of openings are arranged on the side wall of each noise reduction unit, and the openings in two adjacent noise reduction units are staggered, and the noise reduction units are made of sound-absorbing material.

[0007] Preferably, each of the noise reduction units has the same shape and is a cubic shell, and the opening is opened on the side wall of the cubic shell.

[0008] Preferably, each of the noise reduction units has the same height and thickness, and in adjacent noise reduction units, the sound absorption distance is formed between the outer wall of the noise reduction unit located in the inner layer and the inner wall of the noise reduction unit located in the outer layer.

[0009] Preferably, each of the noise reduction units is provided with an opening.

[0010] Preferably, among the two openings of the adjacent noise reduction units, the opening located in the inner layer is opened on the first side wall of the noise reduction unit located in the inner layer, and the opening located in the outer layer is opened on the second side wall of the noise reduction unit located in the inner layer.

[0011] Preferably, the first side wall and the second side wall are arranged opposite to each other.

[0012] Preferably, the width of each sound absorption interval is equal, and the width of each sound absorption interval is equal.

[0013] Preferably, there are three noise reduction units.

[0014] Preferably, when designing each of the noise reduction units, the total acoustic inductance L of the noise reduction brick based on the sound-absorbing metamaterial is obtained by calculation using continuity conditions and boundary conditions:

[0015]

[0016] Among them, ρ air is the air density, a is the length of the cubic shell, b is the width of the cubic shell, t is the thickness of the cubic shell, d is the width of the sound absorption interval, h is the length of the opening, and w is the width of the opening;

[0017] The acoustic resistance R of the noise reduction brick based on the sound-absorbing metamaterial is obtained by calculation:

[0018]

[0019] Among them, μ dyn is the dynamic conductivity of the noise reduction brick based on the sound absorbing metamaterial, ρ 0 is the atmospheric pressure;

[0020] The acoustic resistance and capacitance C of the noise reduction brick based on the sound-absorbing metamaterial is obtained by calculation:

[0021]

[0022] Among them, γ is the sound frequency of the noise;

[0023] After the total acoustic inductance L, acoustic resistance R and acoustic resistance capacitance C of the noise reduction brick based on the sound absorbing meta-material are calculated, since the total acoustic inductance, acoustic resistance and acoustic resistance capacitance are connected in series, the total acoustic impedance Z of the noise reduction brick based on the sound absorbing meta-material is obtained by calculation:

[0024]

[0025] Wherein, i is the current magnitude of the noise reduction brick based on the sound-absorbing metamaterial.

[0026] Compared with the prior art, the present invention has achieved the following technical effects:

[0027] The noise reduction brick based on the sound-absorbing meta-material provided by the present invention has a plurality of noise reduction units nested in sequence, and there is a sound-absorbing spacing between adjacent noise reduction units. The nested noise reduction units can disperse material stress, so that the noise reduction brick based on the sound-absorbing meta-material has high pressure bearing capacity, and its pressure bearing capacity reaches MU10, which meets the requirements of national standards. A plurality of openings are provided on the side wall of each noise reduction unit, so that noise enters through the opening on the outermost noise reduction unit, and enters the corresponding noise reduction unit through each opening in sequence from the outside to the inside, so that air resonates in the noise reduction unit. The Helmholtz resonance technology is used to effectively solve the problem of absorbing medium and low frequency noise of 20Hz to 1000Hz. The openings in two adjacent noise reduction units are staggered to form a spiral sound propagation path, thereby improving the sound absorption and noise reduction effect. At the same time, by changing the size parameters of the noise reduction unit, the absorption of noise of different frequencies is achieved, and the adaptability is improved. The noise reduction unit is made of sound-absorbing material, which effectively achieves sound absorption and noise reduction. Compared with porous sponges, the fire and moisture resistance are improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0029] Figure 1 This is a schematic diagram of the structure of a noise reduction brick based on a sound-absorbing metamaterial in the present invention;

[0030] Figure 2 is a cross-sectional view of a noise reduction brick based on a sound-absorbing metamaterial in the present invention;

[0031] Figure 3 for Figure 2 The main view;

[0032] In the figure: 1-noise reduction unit, 2-opening, 3-sound absorption distance. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] The purpose of the present invention is to provide a noise reduction brick based on sound-absorbing metamaterials to solve the problems existing in the prior art and improve the sound absorption intensity and pressure-bearing capacity.

[0035] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0036] like Figure 1-Figure 3 As shown, the present embodiment provides a noise reduction brick based on a sound-absorbing meta-structure material, comprising a plurality of noise reduction units 1, wherein the plurality of noise reduction units 1 are nested in sequence, and there is a sound-absorbing spacing 3 between adjacent noise reduction units 1, and the nested noise reduction units 1 can disperse material stress, so that the noise reduction brick based on the sound-absorbing meta-structure material has high pressure bearing capacity, and its pressure bearing capacity reaches MU10, which meets the requirements of the national standard, and a plurality of openings 2 are arranged on the side wall of each noise reduction unit 1, so that the noise enters through the opening 2 on the outermost noise reduction unit 1, and enters the corresponding noise reduction unit 1 through each opening 2 from the outside to the inside. The noise reduction unit 1 makes the air resonate in the noise reduction unit 1. The Helmholtz resonance technology is used to effectively solve the problem of absorbing low-frequency noise in the range of 20 Hz to 1000 Hz. The openings 2 in two adjacent noise reduction units 1 are staggered to form a spiral sound propagation path, thereby improving the sound absorption and noise reduction effect. At the same time, by changing the size parameters of the noise reduction unit 1, the absorption of noises of different frequencies is achieved, thereby improving the adaptability. The noise reduction unit 1 is made of sound-absorbing material, thereby effectively achieving sound absorption and noise reduction. Compared with porous sponges, the fire and moisture resistance are improved.

[0037] Specifically, each noise reduction unit 1 has the same shape and is a cubic shell, which makes the structure more stable and has better pressure-bearing capacity. Technical personnel in this field can also choose other shapes according to actual needs. The opening 2 is opened on the side wall of the cubic shell, so that the noise enters the noise reduction unit 1 through one side of the noise reduction unit 1.

[0038] Each noise reduction unit 1 has the same height and thickness. After the multiple noise reduction units 1 are formed, the upper ends of the noise reduction units 1 are fixed as a whole, and the lower ends of the noise reduction units 1 are also fixed as a whole, so that the sound wave path is propagated along each sound absorption interval 3, thereby improving the sound absorption and noise reduction effect. In adjacent noise reduction units 1, a sound absorption interval 3 is formed between the outer wall of the noise reduction unit 1 located in the inner layer and the inner wall of the noise reduction unit 1 located in the outer layer, and multiple sound absorption intervals 3 form an overall spiral arrangement.

[0039] Each noise reduction unit 1 is provided with an opening 2 so that noise can only enter the noise reduction unit 1 through the opening 2 .

[0040] Of the two openings 2 of the adjacent noise reduction units 1, the opening 2 located in the inner layer is opened on the first side wall of the noise reduction unit 1 located in the inner layer, and the opening 2 located in the outer layer is opened on the second side wall of the noise reduction unit 1 located in the inner layer, so that the noise first enters the noise reduction unit 1 in the outer layer through the opening 2 on the first side wall, then passes through the sound absorption distance 3, and then enters the noise reduction unit 1 in the inner layer through the opening 2 on the second side wall.

[0041] The first side wall and the second side wall are arranged opposite to each other, so that in the adjacent noise reduction units 1, after the noise enters the outer noise reduction unit 1 through the outer opening 2, it can propagate to both sides of the opening 2 respectively, and finally enter the inner noise reduction unit 1 through the oppositely arranged inner opening 2. In this process, the propagation path of the sound wave is longer, thereby improving the sound absorption and noise reduction effect.

[0042] The width of each sound absorption interval 3 is equal, and the width of each sound absorption interval 3 is equal.

[0043] There are three noise reduction units 1 , and those skilled in the art can also adaptively change the number of noise reduction units 1 according to actual needs.

[0044] When designing each noise reduction unit 1, in order to make it tunable in sound absorption frequency, the absorption of noise of different frequencies can be achieved by changing the size parameters of each noise reduction unit 1. When considering its Helmholtz resonance, the noise reduction brick based on the sound absorbing structural material composed of the noise reduction unit 1 can be analyzed using the lumped RLC circuit model. The three noise reduction units 1 provide the maximum total acoustic inductance and acoustic resistance, and the inner cavity provides most of the acoustic resistance and capacitance. Using the continuous conditions and boundary conditions, the total acoustic inductance L of the noise reduction brick based on the sound absorbing meta-structure material is calculated:

[0045]

[0046] Among them, ρ air is the air density, a is the length of the cubic shell, b is the width of the cubic shell, t is the thickness of the cubic shell, d is the width of the sound absorption interval 3, h is the length of the opening 2, and w is the width of the opening 2;

[0047] The acoustic resistance R of the noise reduction brick based on the sound-absorbing metamaterial is obtained by calculation:

[0048]

[0049] Among them, μ dyn is the dynamic conductivity of the noise reduction brick based on the sound absorbing metamaterial, ρ 0 is the atmospheric pressure;

[0050] The acoustic resistance and capacitance C of the noise reduction brick based on the sound-absorbing metamaterial is obtained by calculation:

[0051]

[0052] Among them, γ is the sound frequency of the noise;

[0053] After calculating the total acoustic inductance L, acoustic resistance R and acoustic resistance capacitance C of the noise reduction brick based on the sound-absorbing meta-structure material, since the total acoustic inductance, acoustic resistance and acoustic resistance capacitance are connected in series, the total acoustic impedance Z of the noise reduction brick based on the sound-absorbing meta-structure material is calculated:

[0054]

[0055] Where i is the current of the noise reduction brick based on sound-absorbing metamaterial.

[0056] The above calculation formula shows that when any one of the size parameters of the width d, thickness t, width w of opening 2 and height h of opening 2 of the sound absorption spacing 3 of the noise reduction unit 1 is changed, and the other three parameters remain unchanged, the maximum sound absorption of the noise reduction brick based on the sound-absorbing metamaterial does not change much within a certain range, that is, the noise absorption rate is as high as 99%, and only the sound absorption frequency is moved, which broadens the effective frequency range of the noise reduction brick based on the sound-absorbing metamaterial with sound absorption effect and realizes the absorption of noise of different frequencies.

[0057] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A noise reduction brick based on sound-absorbing metamaterial, characterized in that: It comprises a plurality of noise reduction units, which are nested in sequence, and there is a sound-absorbing spacing between adjacent noise reduction units. A plurality of openings are arranged on the side wall of each noise reduction unit, and the openings in two adjacent noise reduction units are staggered. The noise reduction units are made of sound-absorbing material.

2. The noise reduction brick based on the sound absorbing metamaterial according to claim 1 is characterized in that: The noise reduction units have the same shape and are all cubic shells, and the openings are opened on the side walls of the cubic shells.

3. The noise reduction brick based on the sound absorbing metamaterial according to claim 2 is characterized in that: The noise reduction units have the same height and thickness. In adjacent noise reduction units, the sound absorption distance is formed between the outer wall of the noise reduction unit located in the inner layer and the inner wall of the noise reduction unit located in the outer layer.

4. The noise reduction brick based on the sound absorbing metamaterial according to claim 2 is characterized in that: The width of each sound absorption interval is equal, and the width of each sound absorption interval is equal.

5. The noise reduction brick based on the sound absorbing metamaterial according to claim 2 is characterized in that: Each of the noise reduction units is provided with an opening.

6. The noise reduction brick based on the sound absorbing metamaterial according to claim 5 is characterized in that: Of the two openings of the adjacent noise reduction units, the opening located in the inner layer is opened on the first side wall of the noise reduction unit located in the inner layer, and the opening located in the outer layer is opened on the second side wall of the noise reduction unit located in the inner layer.

7. The noise reduction brick based on the sound absorbing metamaterial according to claim 6 is characterized in that: The first side wall is arranged opposite to the second side wall.

8. The noise reduction brick based on the sound absorbing metamaterial according to claim 7 is characterized in that: There are three noise reduction units.

9. The noise reduction brick based on the sound absorbing metamaterial according to claim 8 is characterized in that: When designing each of the noise reduction units, the total acoustic inductance L of the noise reduction brick based on the sound-absorbing metamaterial is obtained by calculation using the continuity condition and the boundary condition: Among them, ρ air is the air density, a is the length of the cubic shell, b is the width of the cubic shell, t is the thickness of the cubic shell, d is the width of the sound absorption interval, h is the length of the opening, and w is the width of the opening; The acoustic resistance R of the noise reduction brick based on the sound-absorbing metamaterial is obtained by calculation: Among them, μ dyn is the dynamic conductivity of the noise reduction brick based on the sound absorbing metamaterial, ρ0 is the atmospheric pressure; the acoustic resistance and capacitance C of the noise reduction brick based on the sound absorbing metamaterial are obtained by calculation: Among them, γ is the sound frequency of the noise; After the total acoustic inductance L, acoustic resistance R and acoustic resistance capacitance C of the noise reduction brick based on the sound absorbing meta-material are calculated, since the total acoustic inductance, acoustic resistance and acoustic resistance capacitance are connected in series, the total acoustic impedance Z of the noise reduction brick based on the sound absorbing meta-material is obtained by calculation: Wherein, i is the current magnitude of the noise reduction brick based on the sound-absorbing metamaterial.

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