Acoustic wave focusing device based on intrinsic displacement mode

An eigenmode and acoustic focusing technology, applied in the field of acoustic metamaterials, can solve the problems of poor focusing effect, difficult processing, complex structure, etc., and achieve the effect of moderate size, wide application range and easy integration

Inactive Publication Date: 2015-04-08
JIANGSU UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0012] Aiming at technical problems such as poor focusing effect, large size, complex structure, and difficult processing of traditional acoustic focusing devices, the present invention proposes an acoustic wave focusing ring structure with excellent focusing effect, wide frequency coverage, simple structure and easy realization

Method used

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  • Acoustic wave focusing device based on intrinsic displacement mode
  • Acoustic wave focusing device based on intrinsic displacement mode
  • Acoustic wave focusing device based on intrinsic displacement mode

Examples

Experimental program
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Effect test

Embodiment 1

[0038] Such as figure 1 As shown, the finite element numerical method is used to establish a metal ring structure model immersed in water to calculate the performance of acoustic wave focusing. Among them, the metal ring structure adopts a brass ring structure, the outer diameter of the ring is R=30.0mm, and the inner diameter is r=25.5mm. The material parameters used in the calculation are: the density of brass is 8400kg / m 3 , the longitudinal wave velocity is 4400m / s and the transverse wave velocity is 2200m / s; the density of water is 998kg / m 3 And the speed of sound is 1483m / s.

[0039] figure 2 (a) is the sound pressure distribution diagram of the brass ring structure excited by a 181.7kHz plane wave. The position of the plane wave is the left boundary (x=-40mm). It can be seen that the incident plane wave is focused at the center of the ring to form a circle shaped focus.

[0040] In order to illustrate that the incident sound wave in any direction excites the ring ...

Embodiment 2

[0044] from figure 2 and image 3 The results can be obtained: when the structural parameters of the brass ring are R=30.0mm and r=25.5mm, the focusing frequency appears around 100kHz.

[0045] Now keep the material parameters of brass and water unchanged, change the inner and outer radii of the brass ring, and the eigenfrequency of the sound wave focus will change. Such as Figure 4As shown in (a) and 4(b), when the inner and outer radii of the brass ring are R=3.0μm and r=2.5μm, the eigenfrequency of the acoustic wave focusing can be as high as 965.0MHz, and when the inner and outer radius of the brass ring is R =6.0m and r=5.0m, the eigenfrequency of acoustic wave focusing can be as low as 190.6Hz, which shows that the focusing frequency range of the annular structure proposed by the present invention is very wide, as long as the inner and outer radii of the annular structure are adjusted, different Acoustic focusing effect of frequency.

Embodiment 3

[0047] In addition, in addition to circular metal ring structures, the acoustic focusing mechanism proposed by the present invention can also be applied to metal ring structures of different shapes, Figure 5 (a) represents the sound pressure distribution diagram of the square brass ring structure excited by a spherical wave with a frequency of 126.1kHz; Figure 5 (b) represents the sound pressure distribution diagram of the elliptical brass ring structure excited by a spherical wave with a frequency of 204.2kHz. The parameters of the square brass ring structure in the calculation are a1=12.5mm, a2=15.0mm; the oval brass ring The shape structure parameters are b1=15.0mm, b2=20.0mm, b3=25.0mm, b4=30.0mm; the parameters of brass and water are the same as figure 2 Likewise, it can be seen that the incident spherical wave is focused inside the ring structure. It shows that the acoustic focusing mechanism based on displacement eigenmodes proposed by the present invention can be a...

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Abstract

The invention belongs to the field of acoustic metamaterial and discloses an acoustic wave focusing device based on an intrinsic displacement mode. The acoustic wave focusing device is a metallic ring-like structure and immersed in water, the metallic ring-like structure is made of copper, iron, steel, aluminum, zinc, gold, silver, nickel and synthetic metal; the acoustic wave focusing device is excellent in acoustic focusing effect, and energy is centralized because the focus is arranged at the central point of the ring-like structure; the frequency coverage area is wide, and the focusing frequency is changed in the range from 100Hz to 1GHz; the acoustic focusing effect is wide in application range and applied for the circular-ring, square or elliptical-ring structure; the acoustic wave focusing device is simple in structure, easy to realize, process and integrate, and proper in size.

Description

technical field [0001] The invention belongs to the field of acoustic metamaterials, in particular to an acoustic wave focusing device based on displacement eigenmodes. Background technique [0002] Sound waves are common energy carriers in real life. If the sound wave focusing effect can be realized, it can be used in various important occasions that require special control of sound energy, such as: medical focused ultrasound therapy, architectural acoustics, ocean acoustics, etc. Therefore, the research on the acoustic focusing effect has very important academic value and application prospect. [0003] An effective way to achieve acoustic focusing is to design an acoustic focusing lens with a gradually changing negative refractive index, and to make the incident acoustic waves converge at one point through phase adjustment. At present, researchers mainly use phononic crystals and acoustic metamaterials to design acoustic focusing lenses. [0004] Focusing lenses based on...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G10K11/26
Inventor 孙宏祥夏建平
Owner JIANGSU UNIV
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