Helmholtz cavity acoustic metamaterial with thin film structure

An acoustic metamaterial and thin-film structure technology, which can be applied to sound-producing instruments, instruments, etc., can solve the problems of narrow frequency band, single sharp peak of transmission coefficient curve, etc., and achieve the effect of reducing difficulty, improving the efficiency of structure layout and low price.

Inactive Publication Date: 2017-05-31
JIANGSU UNIV
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  • Abstract
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Problems solved by technology

[0004] The transmission coefficient curves of the above-mentioned Helmholtz-type acoustic metamaterial structures are studied in a certain frequency range. The ...

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  • Helmholtz cavity acoustic metamaterial with thin film structure
  • Helmholtz cavity acoustic metamaterial with thin film structure
  • Helmholtz cavity acoustic metamaterial with thin film structure

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Embodiment Construction

[0035] The specific implementation manners of the present invention will be described in further detail below in conjunction with the accompanying drawings.

[0036] figure 1 Shown is an embodiment of the Helmholtz cavity acoustic metamaterial with a thin film structure in the present invention. The present invention adds a layer of thin film on the basis of the cylindrical Helmholtz cavity structure, and the thin film is coupled with the cavity structure to change the structure Natural frequency, so as to achieve the effect of low frequency noise control. figure 1 is the unit structure of the acoustic metamaterial, including cavities and membranes; figure 2 is a cross-sectional view of the acoustic metamaterial structure; image 3 is a dimension drawing of the acoustic metamaterial structure.

[0037] Such as image 3 As shown in the dimension diagram, the inner radius of the cylindrical cavity is r, the height of the cavity is H, the wall thickness is t, the depth of ...

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Abstract

The invention provides a Helmholtz cavity acoustic metamaterial with a thin film structure. According to the structure of the metamaterial, the thin film structure is added in the cylindrical Helmholtz cavity. The cylindrical cavity structure is made of aluminium, and the thin film is made of silicone rubber. For the structure, within the frequency range of 500Hz or below, a transmission coefficient curve can generate a plurality of peak values, and the frequency width range corresponding to the peak values can reach 30Hz. By changing the geometrical parameters of the structure, the noise-control acoustic metamaterial structure within the needed low frequency range can be obtained. The cylindrical cavity structure and the thin film structure have good coupling property, and enable the single sharp transmission coefficient curve peak value generated by the traditional Helmholtz cavity to be converted into a plurality of peak values, and the frequency width corresponding to the plurality of peak values is relatively large. The acoustic metamaterial adopting the structure is easy to prepare, the cost of the material is low, and an effective practical application is provided for the noise control within the low frequency range.

Description

technical field [0001] The invention relates to the technical field of acoustic metamaterials for low-frequency noise control, in particular to a Helmholtz cavity acoustic metamaterial with a film structure. Background technique [0002] In modern society, noise in the low-frequency range not only brings serious safety hazards to instruments and equipment in various fields such as industry, aviation, transportation and railways, but also seriously affects people's daily work and life. In the existing low-frequency noise control methods, either a relatively thick traditional concrete wall or a composite material structure with a relatively complex structure is used, which is difficult to prepare and expensive. Due to the characteristics of long wavelength, long propagation distance, and weak fading, low-frequency noise has always been a challenging problem in the field of noise control to effectively control it. [0003] Acoustic metamaterials are composite materials compose...

Claims

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Application Information

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IPC IPC(8): G10K11/162
CPCG10K11/162
Inventor 吴卫国周榕
Owner JIANGSU UNIV
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