Two-dimensional acoustic focusing structure based on sound wave black hole effect
By designing a two-dimensional acoustic focusing structure and utilizing the arrangement and height variation of circumferential and radial baffles, the focusing and dissipation of sound waves in the two-dimensional structure were achieved, solving the problem of insufficient research on two-dimensional acoustic black holes in existing technologies and improving the noise suppression effect.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- 邓杰
- Filing Date
- 2025-07-01
- Publication Date
- 2026-04-24
AI Technical Summary
Existing acoustic black hole technology mainly focuses on one-dimensional acoustic black hole structures, lacking research on two-dimensional structures, which limits its application in practical engineering.
A two-dimensional acoustic focusing structure based on the acoustic black hole effect was designed. An air domain is formed by the combination of upper and lower structural plates and partitions. The focusing and dissipation of sound waves are achieved by the arrangement and height variation of the circumferential and radial partitions.
Extending one-dimensional acoustic black hole technology to two-dimensional structures improves the focusing ability of sound waves and enhances noise suppression.
Smart Images
Figure BDA0005478264270000013 
Figure BDA0005478264270000015 
Figure FDA0005478264260000011
Abstract
Description
Technical Field
[0001] This invention belongs to the field of vibration and noise control technology, and specifically relates to a two-dimensional acoustic focusing structure based on the acoustic black hole effect. Background Technology
[0002] The acoustic black hole effect utilizes the power-law variation of structural thickness or material parameters to cause bent waves to gradually decrease in propagation speed and increase in amplitude, eventually concentrating at the center of the structure, thus achieving effective energy concentration and dissipation. Existing acoustic black hole technology is mainly applied to bent waves in solid structures, while research on sound waves (acoustic black hole effect) primarily focuses on one-dimensional acoustic black hole structures, lacking research on two-dimensional structures. This significantly limits the application of acoustic black hole technology in practical engineering. Summary of the Invention
[0003] To this end, this invention proposes a two-dimensional acoustic focusing structure based on the acoustic black hole effect to improve the focusing ability of sound waves and expand its application in the field of noise reduction.
[0004] To achieve the above objectives, the present invention provides the following solution:
[0005] A two-dimensional acoustic focusing structure based on the acoustic black hole effect is characterized by: upper and lower structural plates, an acoustic black hole structure, an air domain formed between the upper and lower structural plates, and the bottom end of the acoustic black hole structure is arranged on the plate for focusing and dissipating sound waves.
[0006] Preferably, the acoustic black hole structure is composed of circumferential and radial partitions arranged from the inside out. The circumferential partitions can be arranged at equal or unequal intervals, and the number of radial partitions gradually increases according to a linear law, arranged at equal intervals from the inside out. The number of the two sets of partitions is unlimited; generally, the more partitions, the better the wave focusing effect. To improve sound absorption, sound-absorbing materials such as polyester fiber cotton can be filled between the two sets of partitions. The height of the two sets of partitions decreases layer by layer from the inside out, with the highest height at the center, presenting a convex shape. The relationship between their height and position is as follows:
[0007] h = εr m +h0,
[0008] in, The acoustic black hole coefficient, Let x be the radius of the acoustic black hole, (x) c ,y c ) is the center of the acoustic black hole, H is the maximum height of the acoustic black hole, h0 is the minimum height of the acoustic black hole, and m is the power exponent of the acoustic black hole, where m≥1.
[0009] Preferably, the impedance expression formed by the acoustic black hole structure is as follows:
[0010]
[0011] in, Z0 is the wave number, ω is the angular frequency, c0 is the speed of sound, Z0 = ρ0c0 is the air impedance, and ρ0 is the air density.
[0012] Preferably, the sound propagation of the two-dimensional acoustic focusing structure follows the following wave equation:
[0013]
[0014] in, This is the gradient operator.
[0015] Preferably, the acoustic black hole structure is a standard acoustic black hole, but a modified insertion acoustic black hole can also be used, with the following relationship between its height and position:
[0016] h p =Hh,
[0017] Where H is the maximum height of the acoustic black hole, and h is the height parameter of the standard black hole as it changes with position.
[0018] Preferably, the circumferential partition is a disc-shaped annular acoustic black hole, but it is not limited to a circle; it can also be a square, an ellipse, or other annular arrangement. The radial partition is arranged equidistantly in the circumferential direction, but it can also be arranged unequally.
[0019] Preferably, the acoustic black hole structure is symmetrically distributed on the upper and lower plates. Depending on actual needs, other methods such as single, staggered asymmetrical, or multiple periodic arrangements can also be used.
[0020] The present invention has the following beneficial effects:
[0021] 1. The two-dimensional acoustic focusing structure based on the acoustic black hole effect described in this invention extends the existing one-dimensional acoustic black hole technology to a two-dimensional structure, realizing the gradual focusing of incident waves to the central region of the black hole, thereby improving the acoustic focusing capability of the two-dimensional structure.
[0022] 2. The two-dimensional acoustic focusing structure based on the acoustic black hole effect described in this invention adopts an acoustic black hole design with gradually changing partition height, so that the sound waves gathered in the black hole region rub against the upper boundary of the partition, increasing energy loss and effectively improving the noise suppression effect. Attached Figure Description
[0023] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.
[0024] Figure 1 A schematic diagram of a two-dimensional acoustic focusing structure based on the acoustic black hole effect provided by the present invention;
[0025] Figure 2 for Figure 1 The image shows a front view of a two-dimensional acoustic focusing structure based on the acoustic black hole effect;
[0026] Figure 3 for Figure 1 The image shows a top view of a two-dimensional acoustic focusing structure based on the acoustic black hole effect;
[0027] Figure 4 A schematic diagram of a two-dimensional insertion acoustic black hole focusing structure based on the acoustic black hole effect provided by the present invention;
[0028] Figure 5 for Figure 4 The image shows a front view of a two-dimensional insertion acoustic black hole focusing structure based on the acoustic black hole effect;
[0029] Figure 6 for Figure 1 and Figure 4 The sound pressure distribution diagrams of a standard acoustic black hole and an insertion acoustic black hole focusing structure are shown.
[0030] Reference numerals: Upper and lower structural plates 1, acoustic black hole structure 2, circumferential partition 21, radial partition 22. Detailed Implementation
[0031] To better understand the above technical solutions, the following will provide a detailed explanation of the technical solutions in conjunction with the accompanying drawings and specific implementation methods.
[0032] A two-dimensional acoustic focusing structure based on the acoustic black hole effect is characterized by: upper and lower structural plates 1, and an acoustic black hole structure 2. An air domain is formed between the upper and lower structural plates 1. The acoustic black hole structure 2 is a standard circular acoustic black hole, symmetrically distributed in the middle of the structure, and its bottom is connected to the upper and lower plates 1 respectively, for focusing and dissipating sound waves. The acoustic black hole structure 2 is composed of circumferential partitions 21 and radial partitions 22 arranged from the inside out. The circumferential partitions 21 can be arranged at equal intervals, and the number of radial partitions gradually increases according to a linear law, arranged equidistantly from the inside out. Sound-absorbing material can be filled between the two sets of partitions. The height of the two sets of partitions decreases layer by layer from the inside out, and the relationship between their height and position is as follows:
[0033] h = εr m +h0,
[0034] in, The acoustic black hole coefficient, Let x be the radius of the acoustic black hole, (x) c ,y c ) is the center of the acoustic black hole, H is the maximum height of the acoustic black hole, h0 is the minimum height of the acoustic black hole, and m is the power exponent of the acoustic black hole, where m≥1.
[0035] Example 1: As Figure 1 As shown, a two-dimensional acoustic focusing structure based on the acoustic black hole effect is characterized by: upper and lower structural plates 1, and an acoustic black hole structure 2. An air domain is formed between the upper and lower structural plates 1. The acoustic black hole structure 2 is a standard circular acoustic black hole, symmetrically distributed in the middle of the structure, used to focus and dissipate sound waves. The acoustic black hole structure 2 can be directly machined onto the functional structure, or it can be fixed to the functional structure by welding, bolting, or other methods, or an integrated component with the acoustic black hole structure can be directly installed.
[0036] The aforementioned acoustic black hole structure 2 is composed of circumferential partitions 21 and radial partitions 22 arranged from the inside out. The circumferential partitions 21 are arranged at equal intervals in a circumferential manner, while the number of radial partitions 22 gradually increases according to a linear law, arranged at equal intervals in a circumferential manner from the inside out. There is no sound-absorbing material filling between the two sets of partitions. The number N of both sets of partitions is 25, and the height of the partitions decreases layer by layer from the inside out. The relationship between their height and position is as follows:
[0037] h = εr m +h0,
[0038] Among them, the acoustic black hole coefficient ε is 0.18, and the acoustic black hole length L sbh The maximum height H of the sonic black hole is 500 mm, the minimum height h0 is 5 mm, and the power exponent m is 2.
[0039] Example 2: As Figure 4As shown, the difference from Embodiment 1 above is that the acoustic black hole structure 2 is an insertable circular acoustic black hole. The two sets of partitions of the acoustic black hole can be fixed to the upper and lower plates in the height direction by means of single partition support, or all the partitions can be fixed by support rods and inserted between the two plates.
[0040] The sonic black hole structure 2 is composed of circumferential partitions 21 and radial partitions 22 arranged from the inside out. The circumferential partitions 21 are arranged at equal intervals, and the number of radial partitions 22 gradually increases according to a linear law. They are arranged at equal intervals in the circumferential direction from the inside out, and there is no sound-absorbing material filling between the two sets of partitions.
[0041] Both sets of partitions have 25 partitions (N). The height of the partitions decreases layer by layer from the inside to the outside. The relationship between their height and position is as follows:
[0042] h p =Hh,
[0043] Among them, the maximum height H of the acoustic black hole and the standard black hole parameter h are consistent with the standard acoustic black hole parameter.
[0044] Based on the parameters of Examples 1 and 2, the air domains of the standard acoustic black hole focusing structure and the inserted acoustic black hole focusing structure were modeled and simulated, respectively. Figure 6 As shown, Figures (a1) and (a2) are the sound pressure distribution diagrams of a standard acoustic black hole, and Figures (b1) and (b2) are the sound pressure distribution diagrams of an inserted acoustic black hole. It can be seen that after the sound pressure is applied from the left, due to the focusing effect of the acoustic black hole, both configurations exhibit varying degrees of sound wave focusing at different frequencies.
[0045] The foregoing has shown and described the basic principles and beneficial effects of the present invention. However, the present invention is not limited to the above embodiments. Various changes and modifications can be made to the present invention without departing from its effects and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.
Claims
1. A two-dimensional acoustic focusing structure based on the acoustic black hole effect, characterized in that: The upper and lower structural plates (1) and the acoustic black hole structure (2) form an air domain between the upper and lower structural plates (1). The bottom end of the acoustic black hole structure (2) is connected to the plate to gather and dissipate sound waves.
2. The two-dimensional acoustic focusing structure based on the acoustic black hole effect according to claim 1, characterized in that: The acoustic black hole structure (2) is composed of circumferential partitions (21) and radial partitions (22) arranged from the inside out. The height of the partitions decreases layer by layer from the inside out. The relationship between their height and position is as follows: h=εr m +h0, in, The acoustic black hole coefficient, Let x be the radius of the acoustic black hole, (x) c ,y c ) is the center of the acoustic black hole, H is the maximum height of the acoustic black hole, h0 is the minimum height of the acoustic black hole, and m is the power exponent of the acoustic black hole, where m≥1.
3. A two-dimensional acoustic focusing structure based on the acoustic black hole effect according to claim 1, characterized in that: The impedance expression formed by the acoustic black hole structure (2) is as follows: in, Z0 is the wave number, ω is the angular frequency, c0 is the speed of sound, Z0 = ρ0c0 is the air impedance, and ρ0 is the air density.
4. A two-dimensional acoustic focusing structure based on the acoustic black hole effect according to claim 1, characterized in that: The sound propagation in the two-dimensional acoustic focusing structure follows the following wave equation: in, This is the gradient operator.
5. A two-dimensional acoustic focusing structure based on the acoustic black hole effect according to claim 2, characterized in that: The acoustic black hole structure (2) is a standard acoustic black hole, but an improved insertion acoustic black hole can also be used.
6. A two-dimensional acoustic focusing structure based on the acoustic black hole effect according to claim 2, characterized in that: The circumferential partition (21) is a circular annular acoustic black hole, but it is not limited to a circle. It can also be a square, an ellipse or other annular arrangement. The radial partition (22) is arranged circumferentially at equal intervals, but it can also be arranged at other unequal intervals.
7. A two-dimensional acoustic focusing structure based on the acoustic black hole effect according to claim 1, characterized in that: The acoustic black hole structure (2) is symmetrically distributed on the upper and lower plates, and can also be designed and arranged according to actual needs.