CN-122024686-A - Tube bundle composite low-frequency broadband sound absorption metamaterial unit cell with built-in porous lining layer, regulation and control method and sound absorption device

CN122024686ACN 122024686 ACN122024686 ACN 122024686ACN-122024686-A

Abstract

The invention discloses a tube bundle composite low-frequency broadband sound absorption metamaterial unit cell with a built-in porous lining layer, a regulating and controlling method and a sound absorption device, wherein the unit cell specifically comprises an embedded tube bundle plate, a plurality of tube bundles, a back cavity and the porous lining layer; the invention discloses a multi-dimensional sound absorption device, which comprises a back cavity, a porous lining layer, an embedded tube bundle plate, a plurality of tube bundles, a system-level multi-unit parallel optimization innovative design and a sound absorption device, wherein the back cavity is formed by the back cavity, the porous lining layer is closely laminated and laid on each wall surface on the inner side of the back cavity, the embedded tube bundle plate is laid on an opening at one end of the back cavity, a plurality of through holes matched with the diameters of the tube bundles are formed in the embedded tube bundle plate, the tube bundles vertically extend into the back cavity along the embedded tube bundle plate, one end of the tube bundles extending into the back cavity is separated from the inner side surface of the back cavity on which the porous lining layer is laid, and the continuous and efficient broadband sound absorption device is realized through the innovative design of multi-dimensional dissipation in the local resonance-cavity of the tube bundles and the parallel optimization of the system-level multi-unit.

Inventors

CHEN XIAOLONG
CHEN YINGHANG
XU CHI
CUI XIANGXIANG
XIA XIAO

Assignees

西安电子科技大学

Dates

Publication Date: 20260512
Application Date: 20260313

Claims (8)

1. The tube bundle composite low-frequency broadband sound absorption metamaterial unit cell with the built-in porous lining layer is characterized by comprising an embedded tube bundle plate, a plurality of tube bundles, a back cavity and the porous lining layer; the porous lining layer is closely paved on each wall surface on the inner side of the back cavity in a fitting way; the embedded tube bundle plate is laid at an opening at one end of the back cavity, and a plurality of through holes matched with the diameter of the tube bundle are formed in the embedded tube bundle plate; the tube bundles vertically extend into the back cavity along the embedded tube bundle plates, and one end of each tube bundle extending into the back cavity is separated from the inner side of the back cavity where the porous lining layer is paved.
2. The tube bundle composite type low-frequency broadband sound absorption metamaterial unit cell with the built-in porous lining layer, as claimed in claim 1, is characterized in that the embedded tube bundle plate, the plurality of tube bundles, the back cavity and the porous lining layer are of an integrated structure.
3. The tube bundle composite type low-frequency broadband sound absorption metamaterial unit cell with the built-in porous lining layer according to claim 1, wherein the material flow resistance of the porous lining layer is in the range of 5000 N.s/m 4 ~200000N·s/m 4 .
4. A method for regulating and controlling the cell performance of a tube bundle composite type low-frequency broadband sound absorption metamaterial unit with a built-in porous lining layer, which is characterized by comprising the following steps: Maintaining the perforation rate nS a /S A of the unit cell structure constant, wherein n is the number of tube bundles, S a is the cross-sectional area of a single tube bundle, and S A is the back cavity cross-sectional area; The normalized acoustic resistance Re (Zs/Z 0 ) is controlled by adjusting the number of tube bundles and the diameter size of the tube bundles.
5. The method for regulating and controlling the cell performance of the tube bundle composite type low-frequency broadband sound absorption metamaterial unit with the built-in porous lining layer according to claim 4, wherein the regulation and control of the normalized acoustic resistance Re (Zs/Z0) specifically comprises: Increasing the normalized acoustic resistance Re (Zs/Z0) by increasing the number of tube bundles while decreasing the diameter of the tube bundles; Reducing the normalized acoustic resistance Re (Z s /Z 0 ) by reducing the number of tube bundles while increasing the diameter of the tube bundles; Wherein, when Re (Z s /Z 0 ) ≡1, the unit cell structure is in critical damping state, the maximization of the peak value of sound absorption coefficient is realized at the resonance frequency f 0 ; When Re (Z s /Z 0 ) >1, the unit cell structure is in an over-damping state, and the half absorption bandwidth delta f of the unit cell structure is widened compared with a critical damping state on the premise that the resonance frequency f 0 is unchanged; when Re (Z s /Z 0 ) <1, the unit cell structure is in an underdamped state, and its half-absorption bandwidth Δf is narrowed.
6. A broadband sound absorption method based on cooperative dissipation, which adopts the tube bundle type double-pore low-frequency broadband sound absorption metamaterial unit cell as claimed in claim 1-3, and is characterized in that the method comprises the following steps: After the incident sound wave is guided into the back cavity through the tube bundle, resonance is excited in the cavity, specifically, the incident sound wave firstly enters the tube bundle in the resonance cavity through the opening of the tube bundle, the tube bundle is the neck of the Helmholtz resonator, when the sound wave frequency is matched with the resonance frequency of the tube bundle structure, the air column in the tube bundle is subjected to severe vibration to generate local resonance, and the sound energy is efficiently gathered at low frequency; After resonance excitation, the incident sound wave is transferred to the porous lining layer in the cavity for dissipation.
7. A broadband sound absorption device, comprising a plurality of tube bundle composite low-frequency broadband sound absorption metamaterial unit cells with built-in porous lining layers according to any one of claims 1-3, and the device is characterized in that a plurality of unit cell structure arrays are connected in parallel.
8. The broadband sound absorbing apparatus according to claim 7, wherein a plurality of said unit cell structures comprise unit cells having at least two different structural parameters, said structural parameters comprising at least one of tube bundle diameter, tube bundle length and tube bundle number.

Description

Tube bundle composite low-frequency broadband sound absorption metamaterial unit cell with built-in porous lining layer, regulation and control method and sound absorption device Technical Field The invention relates to the technical field of low-frequency noise control of acoustic metamaterials, in particular to a tube bundle composite low-frequency broadband sound absorption metamaterials unit cell with a built-in porous lining layer. The invention also relates to a method for regulating and controlling the performance of the tube bundle composite low-frequency broadband sound absorption metamaterial unit cell with the built-in porous lining layer. The invention also relates to a broadband sound absorption method based on cooperative dissipation. The invention also relates to a broadband sound absorption device. Background The low-frequency noise generally refers to noise below 500Hz, has become a main pollution source in traffic, industrial production and urban building environments due to the characteristics of long wavelength, strong penetrating power and slow attenuation, and seriously harms human health and life quality, and the traditional sound absorption materials such as porous materials have the sound absorption performance of following the principle of 'quarter wavelength' in a low frequency band, and the thickness required by theory is as high as 17 cm to realize effective absorption of the noise of 500Hz, thus severely restricting the application of the sound absorption materials in light and compact engineering scenes with limited space. The presence of acoustic metamaterials provides a new paradigm for thin layer control of low frequency noise. The sound wave is regulated and controlled through artificially designed sub-wavelength local resonance units such as Helmholtz resonators, membrane structures and the like, and high-efficiency low-frequency sound absorption under the condition that the structure thickness is far smaller than the working wavelength is realized. However, such typical resonant metamaterials suffer from an inherent disadvantage of extremely narrow acoustic frequency bands. The high-efficiency sound absorption performance is generally limited to the vicinity of a sharp resonance peak, and the broadband low-frequency noise with continuous spectrum characteristics commonly seen in practical engineering cannot be effectively covered. To widen the sound absorption bandwidth, exploration is currently mainly along two technical paths: 1. multiple resonance coupling path, combining multiple units with different resonance frequencies in parallel, and widening bandwidth by superposing multiple resonance peaks. However, this approach tends to result in a complex structure and increased size, and the "absorption valleys" between the peaks tend to be easily generated, making it difficult to achieve smooth continuous broadband absorption. 2. Material-structure composite path-a composite of a resonant element such as a helmholtz resonator with a broadband sound absorbing porous material. This path theoretically can synergistically exert the low-frequency localization enhancement of resonant structures and the broadband dissipation advantages of porous materials, and is considered as one of the most potential schemes for achieving low-frequency broadband sound absorption. The prior art is as follows: The composite sound absorption structure based on the Helmholtz resonator and the porous material filling is characterized in that the Helmholtz resonator is used for generating resonance at a specific frequency through air column vibration of a neck to collect sound energy in a cavity, the filled porous material utilizes a huge specific surface area and a complex pore structure to efficiently dissipate the concentrated sound energy into heat energy through viscous loss and heat conduction effect, and compared with a pure resonance structure, the composite sound absorption structure has the advantages that the system damping is increased due to the introduction of the porous material, the width of a resonance peak can be widened to a certain extent, and the peak sound absorption coefficient is improved. Problems of the prior art: 1. bandwidth broadening is limited and there are "absorption valleys" where simple filling means are difficult to achieve depth synergy of the resonance mechanism with the porous dissipation mechanism. The porous material mainly provides "over-damped" background absorption, while the formants are still relatively independent, resulting in "absorption valleys" where the sound absorption coefficient is suddenly reduced in frequency bands between the formants, and a truly continuous, smooth, efficient broadband absorption curve cannot be achieved, as shown by the comparison on the right side of fig. 1. 2. The structure and function are coupled, the performance is difficult to regulate, in the scheme, the resonant frequency is regulated and mainly regulated by changin