Petal-shaped inner insertion pipe type underwater Helmholtz resonance cavity structure

An inner tube and petal-shaped technology is applied in the field of petal-shaped inner tube type underwater Helmholtz resonance cavity structure, and can solve the problems of poor low-frequency sound absorption performance, poor lightweight performance, difficult processing and manufacturing, etc. , to achieve excellent low-frequency sound absorption performance, improved acoustic impedance characteristics, good bearing performance and lightweight performance.

CN111696504AActive Publication Date: 2020-09-22XI AN JIAOTONG UNIV +1
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Publication Date
2020-09-22

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Abstract

The invention discloses a petal-shaped inner insertion pipe type underwater Helmholtz resonance cavity structure; a damping lining layer is arranged on the inner wall of a cavity body, a hole is formed in the center of one end of the cavity body, a petal-shaped inner insertion pipe is arranged in the hole, and the petal-shaped inner insertion pipe and the cavity body are connected in a welded or glued mode to form the petal-shaped inner insertion pipe type underwater Helmholtz resonance cavity structure. The petal-shaped inner insertion pipe type underwater Helmholtz resonance cavity structurehas 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, the structure is simple, and manufacturing is easy.
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Description

technical field

[0001] The invention belongs to the technical field of underwater sound absorption, and in particular relates to a petal-shaped inner-pipe-type underwater Helmholtz resonance cavity structure. 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 geometric parameters.

[0003] Bu...

Examples

Embodiment

[0047] Examples of materials:

[0048] Structural steel: characterized by a density of 7850kg / m 3 , Young's modulus 200GPa, Poisson's ratio 0.2.

[0049] Water: characterized by a density of 1000kg / m 3 , sound velocity 1500m / s, dynamic viscosity coefficient 0.00101Pa·s.

[0050] Rubber: characterized by a density of 1100kg / m 3 , Young's modulus 10MPa, Poisson's ratio 0.49, loss factor 0.2.

[0051] Structural dimensions and material selection of comparative examples:

Embodiment 1

[0056] The diameter of the cavity is 30mm, the height of the cavity is 30mm, the diameter of the petal-shaped inner tube is 3mm, the relative roughness of the petal-shaped inner tube is 0.15, the space wave number of the petal-shaped inner tube is 4, the length of the petal-shaped inner tube is 25mm, and the thickness of the damping inner lining 2mm.

Embodiment 2

[0058] The diameter of the cavity is 40mm, the height of the cavity is 40mm, the diameter of the petal-shaped inner tube is 4mm, the relative roughness of the petal-shaped inner tube is 0.2, the space wave number of the petal-shaped inner tube is 6, the length of the petal-shaped inner tube is 30mm, and the thickness of the damping inner lining 3mm.