Damping layer modified underwater sound absorption inner insertion pipe type Helmholtz resonance cavity structure

A damping layer, intubation type technology, applied in the field of acoustic metamaterials, can solve the problems of poor bearing performance, poor low-frequency sound absorption performance, heavy weight, etc., to improve low-frequency sound absorption performance, excellent low-frequency sound absorption performance, structure simple effect

Active Publication Date: 2020-09-22
XI AN JIAOTONG UNIV +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] The technical problem to be solved by the present invention is to provide an underwater sound-absorbing inner tube-type Helmholm modified with a damping layer in view of the deficiencies in the above-mentioned prior art The resonant cavity structure solves the common problems of poor low-frequency sound absorption performance, heavy weight and poor load-bearing performance in traditional underwater sound-absorbing structures

Method used

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  • Damping layer modified underwater sound absorption inner insertion pipe type Helmholtz resonance cavity structure
  • Damping layer modified underwater sound absorption inner insertion pipe type Helmholtz resonance cavity structure
  • Damping layer modified underwater sound absorption inner insertion pipe type Helmholtz resonance cavity structure

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Effect test

Embodiment 1

[0044] The diameter of the cavity is 32mm, the height of the cavity is 30mm, the diameter of the inner tube is 3mm, the length of the inner tube is 25mm, and the thickness of the damping lining is 2mm.

Embodiment 2

[0046] The diameter of the cavity is 50mm, the height of the cavity is 40mm, the diameter of the inner tube is 4mm, the length of the inner tube is 30mm, and the thickness of the damping lining is 4mm.

Embodiment 3

[0048] The diameter of the cavity is 40mm, the height of the cavity is 50mm, the diameter of the inner tube is 2.5mm, the length of the inner tube is 35mm, and the thickness of the damping lining is 3mm.

[0049] see figure 2 , the Helmholtz resonance phenomenon at low frequencies can achieve perfect sound absorption in a certain frequency range. By pasting the damping lining layer on the inner wall of the resonance cavity, the acoustic impedance characteristics of the structure are improved, and the rubber layer provides additional acoustic resistance and sound capacity, forming a Helmholtz-like resonance, so that the invention realizes perfect underwater low frequency sound absorption.

[0050] see figure 2 , the sound absorption coefficient of Example 1 is greater than 0.5 at 125-180 Hz, the half-sound absorption bandwidth is 37%, and perfect sound absorption is achieved at 150 Hz, and the peak value of the sound absorption coefficient is 0.99, which realizes perfect ab...

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Abstract

The invention discloses a damping layer modified underwater sound absorption inner insertion pipe type Helmholtz resonance cavity structure. A damping lining layer is arranged on the inner wall of a cavity, a hole is formed in the center of one end of the cavity, an inner insertion pipe is arranged in the hole, the other end of the cavity is connected with underwater equipment, and the inner insertion pipe and the cavity are connected in a welded or glued mode to form the damping layer modified underwater sound absorption inner insertion pipe type Helmholtz resonance cavity structure. The damping layer modified underwater sound absorption inner insertion pipe type Helmholtz resonance cavity structure has excellent low-frequency sound-absorbing performance and good bearing performance and light weight performance. And more adjustable structural parameters are provided in the design aspect, corresponding adjustment can be conducted according to actual working condition requirements, thestructure is simple, and manufacturing is easy.

Description

technical field [0001] The invention belongs to the technical field of acoustic metamaterials, and in particular relates to an underwater sound-absorbing inner tube-type Helmholtz resonance cavity structure modified by a damping layer. Background technique [0002] Acoustic metamaterials are artificial periodic composite structures with extraordinary acoustic properties different from natural materials, such as acoustic focusing, negative refraction, one-way transmission, acoustic cloaking, etc. In addition, the perfect absorption of low-frequency sound waves by deep subwavelength scale structures is also one of the important special properties of acoustic metamaterials. In aeroacoustics, perfect absorption based on the principle of Helmholtz resonance can be achieved through the structural design of spatial winding or hierarchical perforation. Some of these structures also exhibit broadband absorption through the parallel connection of multiple units with different geometr...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G10K11/172G10K11/162
CPCG10K11/172G10K11/162
Inventor 辛锋先卢天健段明宇周鑫栋于晨磊
Owner XI AN JIAOTONG UNIV
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