阅读说明：本技术 一种可调控水下声波折射角的多频率声超表面 (Multi-frequency sound super surface capable of regulating and controlling underwater sound wave refraction angle ) 是由 胡博 刘凯 李松 王帅印 王世博 杜逸眉 张揽月 时胜国 时洁 于 2021-08-27 设计创作，主要内容包括：本发明提供的是一种可调控水下声波折射角的多频率声超表面,它是由多个均匀介质单元按周期性排列组成的二维阵列平面。本发明较传统周期性超表面结构,能够在更小尺寸的周期性结构下实现多频率水下声波折射声波调控。它包括：均匀介质单元(1)、均匀介质单元(2)、均匀介质单元(3)、均匀介质单元(4)、均匀介质单元(5)、均匀介质单元(6)、均匀介质单元(7)、均匀介质单元(8)以及隔板(9),均匀介质单元(1)、均匀介质单元(2)、均匀介质单元(3)、均匀介质单元(4)、均匀介质单元(5)、均匀介质单元(6)、均匀介质单元(7)、均匀介质单元(8)在水平面上呈周期排列,每两种均匀介质单元间用隔板(9)隔开。(The invention provides a multi-frequency sound super surface capable of regulating and controlling an underwater sound wave refraction angle, which is a two-dimensional array plane formed by periodically arranging a plurality of uniform medium units. Compared with the traditional periodic super-surface structure, the invention can realize the multi-frequency underwater sound wave refraction and sound wave regulation under the condition of a periodic structure with smaller size. It includes: even medium unit (1), even medium unit (2), even medium unit (3), even medium unit (4), even medium unit (5), even medium unit (6), even medium unit (7), even medium unit (8) and baffle (9), even medium unit (1), even medium unit (2), even medium unit (3), even medium unit (4), even medium unit (5), even medium unit (6), even medium unit (7), even medium unit (8) are periodic arrangement on the horizontal plane, separate with baffle (9) between per two kinds of even medium units.)

1. The utility model provides a can regulate and control multifrequency sound super surface of acoustic angle of refraction under water which characterized in that: the uniform medium unit comprises uniform medium units (1) to (8) and partition plates (9), wherein the uniform medium units (1), the uniform medium units (2), the uniform medium units (3), the uniform medium units (4), the uniform medium units (5), the uniform medium units (6), the uniform medium units (7) and the uniform medium units (8) are arranged periodically on a horizontal plane, and every two kinds of uniform media are separated by the partition plates (9).

2. The multi-frequency acoustic metasurface capable of modulating an angle of refraction of an underwater acoustic wave according to claim 1, wherein: the uniform medium unit (1), the uniform medium unit (2), the uniform medium unit (3), the uniform medium unit (4), the uniform medium unit (5), the uniform medium unit (6), the uniform medium unit (7) and the uniform medium unit (8) are the same in size, the medium width is w, the range of w is 0.01m to 0.04m, the medium height h is 0.15m, and the impedance of the uniform medium unit (1) is Z₁＝1.5×10⁶Pa s/m, the impedance of the homogeneous dielectric unit (2) being Z₂＝1.77×10⁶Pa s/m, the impedance of the homogeneous dielectric unit (3) being Z₃＝1.55×10⁶Pa s/m, the impedance of the homogeneous dielectric unit (4) being Z₄＝1.13×10⁶Pa s/m, the impedance of the homogeneous dielectric unit (5) being Z₅＝1.38×10⁶Pa.s/m, and the impedance of the uniform medium unit (6) is Z₆＝1.27×10⁶Pa s/m, the impedance of the homogeneous dielectric unit (7) is Z₇＝1.08×10⁶Pa s/m, the impedance of the homogeneous dielectric unit (8) being Z₈＝1.02×10⁶Pa·s/m。

3. The multi-frequency acoustic metasurface capable of modulating an angle of refraction of an underwater acoustic wave according to claim 1, wherein: the width of the partition plate (9) is p, the range of p is 0.00875m to 0.01875m, the height h is 0.15m, the partition plate is made of steel, and the impedance of the steel is 46.8 multiplied by 10⁶Pa·s/m。

4. The multi-frequency acoustic metasurface capable of modulating an angle of refraction of an underwater acoustic wave according to claim 3, wherein: the uniform medium units (1) to (8) and the partition boards (9) are bonded by an adhesive to form a period, the period width d is 8(w + p), each periodic structure is bonded by the adhesive to form an acoustic super-surface, and the acoustic super-surface structure at least comprises 2 periods.

5. The multi-frequency acoustic metasurface capable of modulating an angle of refraction of an underwater acoustic wave according to claim 1, wherein: the cross sections of the uniform medium units (1) to (8) and the partition plates (9) are all rectangular.

6. The controllable underwater acoustic refraction angle multi-frequency acoustic metasurface of claim 1, wherein: the acoustic super surface can regulate and control a plurality of frequencies of which f is 10000Hz, 20000Hz, 30000Hz and 40000 Hz.

Technical Field

The invention belongs to the technical field of acoustic super-surfaces, and particularly relates to a multi-frequency acoustic super-surface capable of regulating and controlling an underwater acoustic wave refraction angle.

Background

In recent years, the acoustic metamaterial has rapid development, has different extraordinary performances from the traditional acoustic material, can greatly expand and improve the regulation and control modes of people on sound waves, and can realize a plurality of unique acoustic phenomena, such as abnormal reflection and abnormal transmission of the sound waves, sound wave focusing, a spiral sound field, perfect sound absorption, sound stealth and other functions. However, the conventional artificial metamaterial has the disadvantages of overlarge volume, high manufacturing cost, narrow frequency bandwidth, large acoustic loss and the like. Therefore, an acoustic super surface, which is a product of an acoustic super material after being designed to be light and thin, is generated, the acoustic super surface is formed by arranging a series of sub-wavelength-sized microstructures on a plane, and the amplitude and the phase of sound waves can be changed through the microstructures, so that the sound waves are regulated and controlled. The acoustic super-surface has many advantages, such as lightness, thinness, simple design, wide application and the like.

The acoustic super-surface structures that are more common today include: (1) a coiled space structure. The structure is internally provided with a curled channel, so that the propagation path of sound waves in the structure is increased. (Houming, Wu Jiu Hui, maze type acoustic super-surface adjustable parameters and full phase adjustment thereof [ J ] Ci' an university of transportation, 2018,52(05):29-37.) (2) a coupling resonance type unit structure. This structure realizes high transmittance by coupling resonance between cells. (field, regulation and control of transmission type super surface to sound wave and application research [ D ]. Nanjing university, 2018.) (3) Helmholtz resonator unit structure. The structure consists of helmholtz resonator units with different geometrical parameters. (Kemeng Gong, Xiaoofan Wang, Huajiang Ouyang, Juliang Mo. tunable gradient Helmholtz-responsive-based acidic measuring for acidic focusing [ J ]. Journal of Physics D: Applied Physics,2019,52(38): 4) five-mode material unit structure. The structure can simultaneously adjust the module parameters and the density of each unit, thereby realizing abnormal refraction and other phenomena. (Yang Chu, Zhuohong Wang, Zhuo xu. Broadband high-efficiency control by specific acidic measuring surface [ J ]. Physics Letters A,2020,384 (11))

The structure can realize the random regulation and control of the refracted sound wave, but still has the defects of larger volume, complex structure, high manufacturing difficulty, single frequency and the like. Since the advent of the public, acoustic surfaces have been used mostly in air, and the research on water as a background medium is extremely poor. Therefore, it is very necessary to manufacture a super-surface structure with a light and thin structure, simple manufacture and multi-frequency adjustment for regulating and controlling underwater refracted sound waves.

Disclosure of Invention

The invention aims to provide a multi-frequency sound ultrasonic surface with a simple structure and an adjustable underwater sound wave refraction angle.

The invention is realized by the following technical scheme:

the medium comprises uniform medium units (1), uniform medium units (2), uniform medium units (3), uniform medium units (4), uniform medium units (5), uniform medium units (6), uniform medium units (7), uniform medium units (8) and partition plates (9), wherein the uniform medium units (1), the uniform medium units (2), the uniform medium units (3), the uniform medium units (4), the uniform medium units (5), the uniform medium units (6), the uniform medium units (7) and the uniform medium units (8) are arranged periodically, and every two media are separated by the partition plates (9).

The uniform medium unit (1), the uniform medium unit (2), the uniform medium unit (3), the uniform medium unit (4), the uniform medium unit (5), the uniform medium unit (6), the uniform medium unit (7) and the uniform medium unit (8) are the same in size, the medium width is w, the range of w is 0.01m to 0.04m, the medium height h is 0.15m, and the impedance of the uniform medium unit (1) is Z₁＝1.5×10⁶Pa s/m, the impedance of the homogeneous dielectric unit (2) isZ₂＝1.77×10⁶Pa s/m, the impedance of the homogeneous dielectric unit (3) being Z₃＝1.55×10⁶Pa s/m, the impedance of the homogeneous dielectric unit (4) being Z₄＝1.13×10⁶Pa s/m, the impedance of the homogeneous dielectric unit (5) being Z₅＝1.38×10⁶Pa s/m, the impedance of the homogeneous dielectric unit (6) being Z₆＝1.27×10⁶Pa s/m, the impedance of the homogeneous dielectric unit (7) is Z₇＝1.08×10⁶Pa s/m, the impedance of the homogeneous dielectric unit (8) being Z₈＝1.02×10⁶Pa·s/m。

The width of the partition plate (9) is p, the range of p is 0.00875m to 0.01875m, the height h is 0.15m, the partition plate is made of steel, and the impedance of the steel is 46.8 multiplied by 10⁶Pa·s/m。

The uniform medium units (1) to the uniform medium (8) and the partition boards (9) are bonded by an adhesive to form a period, the period width d is 8(w + p), each periodic structure is bonded by the adhesive to form an acoustic super-surface, and the acoustic super-surface structure at least comprises 2 periods.

The cross sections of the uniform medium units and the partition plates are rectangular.

The acoustic super surface can regulate and control a plurality of frequencies of which f is 10000Hz, 20000Hz, 30000Hz and 40000 Hz.

Compared with the prior art, the invention has the beneficial effects that:

1. the device designs the super surface by changing the sound velocity of the uniform medium unit, and has a simple structure.

2. The relationship between the period width d and the wavelength lambda is adjusted to adjust the refraction angle, and the variation parameter is less.

3. The device can realize abnormal refraction at any angle of incidence.

4. The device can realize multi-frequency sound wave regulation and control and has frequency selectivity.

Drawings

Fig. 1 is an abstract attached drawing.

FIG. 2 is a geometric schematic of an acoustic metasurface of the present invention.

Fig. 3 shows the total sound pressure field corresponding to f 10000Hz in example 1.

Fig. 4 shows the total sound pressure field corresponding to f 20000Hz in example 1.

Fig. 5 shows simulation results of the refraction direction of the refracted acoustic wave in example 1.

Fig. 6 shows the total sound pressure field corresponding to f 10000Hz in example 2.

Fig. 7 shows the total sound pressure field corresponding to f 20000Hz in example 2.

Fig. 8 shows simulation results of the refraction direction of the refracted acoustic wave in example 2.

Detailed Description

The invention is further illustrated with reference to the following figures and examples.

Referring to fig. 1-8, the multi-frequency acoustic ultrasonic surface capable of regulating and controlling an underwater acoustic refraction angle of the present invention includes uniform medium units (1), uniform medium units (2), uniform medium units (3), uniform medium units (4), uniform medium units (5), uniform medium units (6), uniform medium units (7), uniform medium units (8) and partition plates (9), wherein the uniform medium units (1), the uniform medium units (2), the uniform medium units (3), the uniform medium units (4), the uniform medium units (5), the uniform medium units (6), the uniform medium units (7) and the uniform medium units (8) are periodically arranged, and every two uniform medium units are separated by a partition plate (9).

The uniform medium units have the same size, the widths of the uniform medium units are w, the range of w is 0.01m to 0.04m, the height h of the uniform medium units is 0.15m, and the impedance of the uniform medium units (1) is Z₁＝1.5×10⁶Pa s/m, the impedance of the homogeneous dielectric unit (2) being Z₂＝1.77×10⁶Pa s/m, the impedance of the homogeneous dielectric unit (3) being Z₃＝1.55×10⁶Pa s/m, the impedance of the homogeneous dielectric unit (4) being Z₄＝1.13×10⁶Pa s/m, the impedance of the homogeneous dielectric unit (5) being Z₅＝1.38×10⁶Pa.s/m, and the impedance of the uniform medium unit (6) is Z₆＝1.27×10⁶Pa s/m, the impedance of the homogeneous dielectric unit (7) is Z₇＝1.08×10⁶Pa s/m, the impedance of the homogeneous dielectric unit (8) being Z₈＝1.02×10⁶Pa·s/m。

The width of the partition plate (9) is p, the range of p is 0.00875m to 0.01875m, the height h is 0.15m, the partition plate is made of steel, and the impedance of the steel is 46.8 multiplied by 10⁶Pa·s/m。

The acoustic super-surface structure is characterized in that the uniform medium unit (1), the uniform medium unit (2), the uniform medium unit (3), the uniform medium unit (4), the uniform medium unit (5), the uniform medium unit (6), the uniform medium unit (7), the uniform medium unit (8) and the partition board (9) are bonded by adhesives to form a period, the period width d is 8(w + p), the bonding agents are bonded with one another to form the acoustic super-surface between every two periods, and the acoustic super-surface at least comprises 2 periods.

The cross sections of the uniform medium unit (1), the uniform medium unit (2), the uniform medium unit (3), the uniform medium unit (4), the uniform medium unit (5), the uniform medium unit (6), the uniform medium unit (7), the uniform medium unit (8) and the partition plate (9) are all rectangular.

The acoustic super surface can regulate and control a plurality of frequencies of which f is 10000Hz, f is 20000Hz, f is 30000Hz and f is 40000 Hz. The angle of the refracted sound wave generated by the super surface can be theoretically calculated through the generalized snell's law, and the theoretical calculation formula of the refraction angle under the incident condition of any angle is theta_t＝arcsin(sinθ_i+ λ/d), λ/d being the ratio of the wavelength of the acoustic wave to the period width, θ_iIs the angle of incidence. When the incident angle theta_iThe theoretical calculation formula of the refraction angle can be expressed as θ when 0 °_t＝arcsin(λ/d)。

Example 1:

when the acoustic wave frequency f is 10000Hz, the background medium is water, the acoustic wave is incident on the acoustic super surface at 30 degrees, the super surface structure parameters are w 0.025m, p 0.0125m and d 0.3m, simulation calculation is carried out by using COMSOL Multiphysics software. Fig. 3 shows the result of the total sound pressure field when f is 10000Hz, and fig. 4 shows the result of the total sound pressure field when f is 20000Hz, the left boundary of the acoustic super surface is located at x is 0, sound waves are incident on the acoustic super surface from the left boundary, and exit from the right boundary x is-h. Fig. 5 shows simulation results of refraction directions of refracted sound waves. As shown in fig. 2 and 3, it can be seen thatFor a plane wave incident at 30 deg., the refracted acoustic wave is significantly shifted. Angle of refraction θ according to snell's law_tAngle of incidence theta_iThe theoretical refraction angle is 30 degrees, the simulated refraction angle is not equal to the theoretical refraction angle, and therefore the phenomenon of abnormal refraction of the acoustic super surface is proved. The theoretical refraction angle is 0 degrees when lambda/d is 0.5 according to the formula of the generalized snell's law, the refraction angle obtained through the graph 5 is 0 degrees, and the simulation value is well matched with the theoretical value, so that the super surface can realize multi-frequency regulation and control of the underwater refracted sound wave angle through a simple structure.

Example 2:

when the frequency f of the sound wave is 10000Hz, the background medium is water, the sound wave is incident on the acoustic super surface at 30 degrees, the super surface structure parameters are w is 0.02m, p is 0.0075m, and d is 0.22m, simulation calculation is carried out by using COMSOL Multiphysics software. Fig. 6 shows the result of the total sound pressure field when f is 10000Hz, fig. 7 shows the result of the total sound pressure field when f is 20000Hz, and fig. 8 shows the simulation result of the refraction direction of the refracted sound wave. As shown in fig. 6 and 7, it can be seen that the refracted acoustic wave undergoes a significant shift for a plane wave incident at 30 °. Angle of refraction θ according to snell's law_tAngle of incidence theta_iThe theoretical refraction angle is 30 degrees, the simulated refraction angle is not equal to the theoretical refraction angle, and therefore the phenomenon of abnormal refraction of the acoustic super surface is proved. The theoretical refraction angle is 10.48 degrees when λ d is 0.5 according to the generalized snell's law formula, the refraction angle obtained through fig. 8 is 10.48 degrees, and the simulated value is well matched with the theoretical value, so that the super-surface can realize multi-frequency regulation and control of the underwater refracted sound wave angle through a simple structure.