A biomimetic high-load helmholtz resonator

Abstract

The bionic high-bearing Helmholtz resonator belongs to the field of engineering bionics and acoustic superstructure, and aims to solve the technical problem that traditional sound-absorbing materials are difficult to have excellent mechanical properties. The resonator comprises a plurality of top plates, a plurality of bionic Helmholtz resonator arrays and a bottom plate; one of the top plates is located above one of the bionic Helmholtz resonator arrays to form a bionic Helmholtz resonator array unit, a plurality of the bionic Helmholtz resonator array units are arranged from top to bottom, and the lowermost bionic Helmholtz resonator array unit is arranged on the bottom plate. The bionic high-bearing Helmholtz resonator can meet the requirements of perfect sound-absorbing cavity structure design and high sound-absorbing coefficient, reshape the structure of the sound-absorbing unit, significantly improve the overall toughness and strength of the sound-absorbing device, prolong the service life of the sound-absorbing device and develop new application directions. The overall structure of the sound-absorbing structure is light, thin and compact, and the mechanical properties such as compression resistance and bending resistance are significantly improved, and the sound-absorbing structure is easy to manufacture and use.

Description

Technical Field

[0001] The invention belongs to the field of engineering bionics and acoustic superstructures, and relates to a bionic high-load Helmholtz resonator. Background Art

[0002] As noise increasingly impacts human production and daily life, effective absorption of low-frequency noise has become a research priority. The acoustic Helmholtz cell, as an effective sound-absorbing structure, has garnered widespread attention. A Helmholtz cell consists of a closed resonant cavity connected to a neck tube. When sound waves propagate through the cavity, resonance occurs if the frequency of the incident sound wave matches the cavity's natural vibration frequency. This resonance converts the sound wave's energy into heat, thereby absorbing noise.

[0003] Helmholtz cells are widely used in passenger vehicles such as aerospace and rail transit, as well as certain military equipment requiring concealed operation. Besides sound absorption, the mechanical properties of Helmholtz cells are also crucial. As common engineering structures, Helmholtz cells are typically wrapped around noise sources such as engines. They must not only absorb sound but also exhibit excellent vibration and energy absorption capabilities. These mechanical properties not only reduce noise transmission but also protect critical components in accidents, minimizing impact damage.

[0004] Therefore, further optimizing the mechanical properties of the Helmholtz unit will provide comprehensive technical support for solving broadband noise problems and lay the foundation for the design of multifunctional acoustic structures. Summary of the Invention

[0005] In order to solve the problems existing in the prior art, the present invention provides a bionic high-load Helmholtz resonator, which aims to solve the technical problem that it is difficult to combine traditional sound-absorbing materials with excellent mechanical properties.

[0006] The technical solutions adopted by the present invention to solve the technical problems are as follows:

[0007] A bionic high-load-bearing Helmholtz resonator comprises a plurality of top plates, a plurality of bionic Helmholtz resonator arrays and a bottom plate; one of the top plates is located above one of the bionic Helmholtz resonator arrays to form a group of bionic Helmholtz resonator array units; the plurality of bionic Helmholtz resonator array units are arranged from top to bottom, and the lowest bionic Helmholtz resonator array unit is arranged on the bottom plate.

[0008] Preferably, the bionic Helmholtz resonator array is composed of a plurality of bionic Helmholtz resonator monomers.

[0009] Preferably, the bionic Helmholtz resonator monomer consists of a bionic Helmholtz resonator unit shell and a bionic Helmholtz resonator unit cavity.

[0010] Preferably, the biomimetic Helmholtz resonator unit cavity is a variable cross-section hollow structure with a predetermined wall thickness length ratio.

[0011] Preferably, the upper bottom surface of the biomimetic Helmholtz resonator unit cavity is circular, the lower bottom surface is square, and the center lines of the upper and lower bottom surfaces are perpendicular to the upper and lower bottom surfaces, respectively.

[0012] Preferably, the variable cross-section of the biomimetic Helmholtz resonator unit shell has a taper.

[0013] Preferably, a plurality of sound absorption cavity communication holes are provided on the top plate.

[0014] Preferably, the sound absorption cavity communication hole is a cylinder, the diameter of the cylinder is smaller than the diameter of the upper bottom surface of the biomimetic Helmholtz resonator unit cavity, and the center axis of the cylinder coincides with the connecting line of the upper and lower bottom surfaces.

[0015] The beneficial effects of the present application are: the present application remolds the sound absorption unit structure by biomimetic energy absorption structure and natural bamboo node variable taper structure and bird feather shaft variable cross-section structure, under the premise of meeting perfect sound absorption cavity structure design and having high sound absorption coefficient, significantly improves the overall toughness and strength of the sound absorption device, prolongs the service life of the sound absorption device and develops new application direction. The overall structure of the sound absorption structure proposed by the present application is light, thin and compact, and the mechanical properties such as compression resistance and bending resistance are significantly improved, and it is easy to manufacture and use. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 A biomimetic high-bearing Helmholtz resonator three-dimensional structure diagram.

[0017] Figure 2 A biomimetic high-bearing Helmholtz resonator resonant unit BB direction sectional view.

[0018] Figure 3 A biomimetic high-bearing Helmholtz resonator embodiment different wave band different sound hole diameter sound absorption effect curve diagram.

[0019] In the figure: 10, top plate, 11, sound absorption cavity communication hole, 20, biomimetic Helmholtz resonator array, 21, biomimetic Helmholtz resonator monomer, 22, biomimetic Helmholtz resonator unit shell, 23, biomimetic Helmholtz resonator unit cavity, 30, bottom plate. DETAILED DESCRIPTION

[0020] In order to make the above features and advantages of the present application more obvious and easy to understand, the present application will be further described in detail below with reference to the drawings, but the protection scope of the present application should not be limited thereby.

[0021] As shown in Figure 1 A bionic high-bearing Helmholtz resonator, which comprises a plurality of top plates 10, a plurality of bionic Helmholtz resonator arrays 20 and a bottom plate 30; one top plate 10 is located above one bionic Helmholtz resonator array 20 to form a bionic Helmholtz resonator array unit, a plurality of bionic Helmholtz resonator array units are arranged from top to bottom, and the lowermost bionic Helmholtz resonator array unit is arranged on the bottom plate 30. The bionic Helmholtz resonator array is composed of a plurality of bionic Helmholtz resonator units 21, which are closely arranged according to their geometric characteristics to form the bionic Helmholtz resonator array 20. The bionic Helmholtz resonator unit 21 includes but is not limited to other arrangement styles such as circular array, prismatic array, etc. The bionic Helmholtz resonator array 20 of the embodiment only needs to be connected with the contact surface between the upper and lower top plates 10, without the need to connect different bionic Helmholtz resonator units 21, which simplifies the manufacturing process, reduces the use of auxiliary materials such as adhesives and structural design defects caused by interface connection, and ensures the sound absorption and energy absorption efficiency. According to the geometric characteristics of the bionic Helmholtz resonator unit 21, the structure characteristics of the bionic Helmholtz resonator unit 21 are fully utilized, and the closed space is beneficial to convert the impact kinetic energy into heat energy and dissipate it, so that the energy absorption characteristics are further enhanced. In the embodiment, the plurality of bionic Helmholtz resonator units 21 are arranged in a rectangular array with a center distance of 5mm*5mm.

[0022] As shown in Figure 2 The bionic Helmholtz resonator unit 21 is composed of a bionic Helmholtz resonator unit shell 22 and a bionic Helmholtz resonator unit cavity 23. The bionic Helmholtz resonator unit cavity 23 of the embodiment simulates the structure characteristics of the inner taper of bamboo joints and the variable cross-section of bird shafts. The bionic Helmholtz resonator unit cavity 23 is a variable cross-section hollow structure with a predetermined wall thickness length ratio. The variable cross-section of the bionic Helmholtz resonator unit shell 22 has a taper. In the embodiment, the taper of the inner wall of the bionic Helmholtz resonator unit shell 22 is within 0.002-0.003, and the ratio of the maximum wall thickness to the outer diameter of the bionic Helmholtz resonator unit shell 22 is not higher than 0.5. The upper bottom surface of the bionic Helmholtz resonator unit cavity 23 is circular, the lower bottom surface is square, and the center lines of the upper and lower bottom surfaces are perpendicular to the upper and lower bottom surfaces, respectively. In the embodiment, the circular diameter D2=2.8mm, the square side length L3=3mm, the bionic Helmholtz resonator unit cavity 23 height H2=8mm, the bionic Helmholtz resonator unit shell 22 maximum wall thickness L1=1.024mm, and the minimum wall thickness L2=1mm.

[0023] The bionic Helmholtz resonator unit cavity 23 mainly plays two roles, one is to provide an inner cavity of a sound absorption structure, and based on the resonance of the bionic Helmholtz resonator monomer 21, sound wave energy is dissipated to achieve a predetermined sound absorption effect. The second is to use the bionic Helmholtz resonator unit shell 22 as the main body of the mechanical bearing structure to enhance the stability and large deformation resistance of the bionic Helmholtz resonator monomer 21.

[0024] The bionic Helmholtz resonator monomer 21 adopts a hollow cavity structure with a variable cross-section and a gradient wall thickness, which changes the deformation mode under load such as impact load, and the gradual stability of the gradient wall thickness structure can prolong the deformation stroke and ensure the stability of the structure. At the same time, the regular shape of the upper and lower cross-sections can simplify the manufacturing and achieve the requirements of specific array arrangement.

[0025] The top plate 10 is provided with a plurality of sound absorption cavity communication holes 11. The thickness H1 of the top plate 10 is 1 mm, and the diameter D1 of the sound absorption cavity communication hole 11 is 1.36 mm. The sound absorption cavity communication hole 11 is a cylinder, the diameter of the cylinder is smaller than the diameter of the upper bottom surface of the bionic Helmholtz resonator unit cavity 23, and the center axis of the cylinder coincides with the line connecting the upper and lower bottom surfaces. The thickness H3 of the bottom plate 30 is 2 mm.

[0026] As shown in Figure 3 , the materials used in the simulation are as follows: the density of the photosensitive resin is 1150 kg / m 3 , the Young's modulus is 3.5 GPa, and the Poisson's ratio is 0.35; the density of air is 1.29 kg / m 3 , the sound speed is 343 m / s, and the dynamic viscosity coefficient is 1.81×10 -5 Pa•s.

[0027] The above materials are used to test and simulate the sound absorption cavity communication hole 11 with different sizes, and the structure design can make the sound absorption device achieve excellent sound absorption effect under different wave bands. In particular, for the sound absorption structure bionic Helmholtz resonator array 20 with a sound absorption cavity communication hole 11 of 1.36 mm, the sound absorption coefficient of the bionic Helmholtz resonator array 20 is above 0.4 in the 3200-3600 Hz wave band, achieving medium sound absorption effect; the sound absorption coefficient is above 0.8 in the 3315-3470 Hz wave band, achieving high sound absorption effect; and the highest sound absorption coefficient is 0.9993 in the 3391 Hz wave band, which can be considered as complete sound absorption in this wave band.

[0028] The above results show that by designing the cavity structure and changing the hole diameter of the sound absorption cavity communication hole 11, the bionic Helmholtz resonator array 20 can have better sound absorption performance at different frequencies. By combining multiple bionic Helmholtz resonator unit cavities 23 with specific parameters, the sound absorption performance and lightweight energy absorption performance can be achieved in a wide frequency range.

[0029] Compared with the traditional Helmholtz resonance structure, the structural bearing capacity and energy absorption effect are enhanced in this embodiment, which is suitable for the design and preparation of sound absorption and energy absorption coupling materials for large equipment.

Claims

1. A biomimetic high load Helmholtz resonator characterized by, The resonator comprises a plurality of top plates, a plurality of bionic Helmholtz resonator arrays and a bottom plate; one of the top plates is located above one of the bionic Helmholtz resonator arrays to form a bionic Helmholtz resonator array unit, a plurality of the bionic Helmholtz resonator array units are arranged from top to bottom, and the lowermost bionic Helmholtz resonator array unit is arranged on the bottom plate; The bionic Helmholtz resonator array is composed of a plurality of bionic Helmholtz resonator units; the bionic Helmholtz resonator unit is composed of a bionic Helmholtz resonator unit shell and a bionic Helmholtz resonator unit cavity; the bionic Helmholtz resonator unit cavity is a variable cross-section hollow structure with a predetermined wall thickness length ratio; the upper bottom surface of the bionic Helmholtz resonator unit cavity is circular, the lower bottom surface is square, and the center lines of the upper and lower bottom surfaces are perpendicular to the upper and lower bottom surfaces, respectively; the variable cross-section of the bionic Helmholtz resonator unit shell has a taper.

2. A biomimetic high load Helmholtz resonator according to claim 1, characterized in that, A plurality of sound absorption cavity communication holes are arranged on the top plate.

3. A biomimetic high load Helmholtz resonator according to claim 2, characterized in that, The sound absorption cavity communication hole is a cylinder, the diameter of the cylinder is smaller than the diameter of the upper bottom surface of the bionic Helmholtz resonator unit cavity, and the central axis of the cylinder coincides with the connecting line of the upper and lower bottom surfaces.

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