Multistage ring-cavity coupling model, acoustic metasurface material and reflective stealth structure

An acoustic metasurface, coupled model technology, applied in the direction of sounding equipment, instruments, etc., can solve the problem of difficult to achieve stealth function, and achieve the effect of excellent stealth effect, great flexibility, and wide application range.

Pending Publication Date: 2021-11-12
NORTHWESTERN POLYTECHNICAL UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, due to the model's small influence on the phase of the acoustic wave, it is difficult to achieve the desired stealth function

Method used

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  • Multistage ring-cavity coupling model, acoustic metasurface material and reflective stealth structure
  • Multistage ring-cavity coupling model, acoustic metasurface material and reflective stealth structure
  • Multistage ring-cavity coupling model, acoustic metasurface material and reflective stealth structure

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Experimental program
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Effect test

Embodiment 1

[0036] First, this embodiment designs a simple resonant cavity, such as figure 1 As shown, four openings are opened around a ring structure, the large cavity in the middle can be regarded as a sound volume, and the four small openings around can be regarded as four senses connected to the sound volume, which can also make a specific The frequency of the incident wave resonates within this structure. There is a phase difference between the vibration phase of the air in the cavity and the incident wave. When resonance occurs, the vibration of the air in the cavity can significantly affect the phase of the reflected wave, which may be in phase or anti-phase with the incident wave. There is also a high probability of observing the appearance of negative mass density during the measurement. At the resonant frequency, different reflected wave phases can be obtained by rotation.

[0037] On this basis, this embodiment discloses a multi-level ring-cavity coupling model, as shown in ...

Embodiment 2

[0046] Based on the same inventive concept, this embodiment also provides an acoustic metasurface material, in which multiple multi-level ring-cavity coupling models are tiled periodically to form a group of acoustic metasurface materials.

[0047] Specifically, the ring opening widths or rotation angles of different multistage ring-cavity coupling models are different.

[0048] This example is in Figure 4 Select a relatively uniform region in , and select 8 unit structures (that is, multi-level ring-cavity coupling model) to form a period at an interval of π / 4. These unit structures are tiled periodically to form an acoustic metasurface material. This metasurface material satisfies the requirements of the phase change gradient in the generalized Snell's law, so this metasurface material can observe the abnormal reflection and negative reflection phenomenon of the generalized Snell's law. When selecting the unit structure, the same phase change can have multiple unit struct...

Embodiment 3

[0051] When a sound wave is incident on an object on a flat ground, since the shape of the object itself has a certain bulge relative to the flat ground, its scattering behavior for the incident wave is destined to be completely different from that of the background ground, so the object will be will be detected by the detector. Based on the same inventive concept and on the basis of the research on the above-mentioned acoustic metasurface materials, this embodiment also discloses a reflective stealth structure, in which multiple groups of acoustic metasurface materials are arranged to form a reflective stealth structure, and objects that need to be invisible are placed Under the reflective stealth structure, carpet-like stealth is realized.

[0052] Specifically, what this implementation provides is a reflective acoustic invisibility cloak. Find out the unit structures that meet the conditions in the above model, arrange these unit structures to form the required metasurface ...

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PUM

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Abstract

The invention provides a multistage ring-cavity coupling model, an acoustic metasurface material and a reflective stealth structure, and belongs to the field of acoustic stealth materials; the multistage ring-cavity coupling model comprises a plurality of circular rings which are movably nested in sequence from inside to outside, each circular ring is provided with a plurality of openings, and a cavity is formed between every two adjacent circular rings; the openings in every two adjacent circular rings are arranged in a staggered mode, the opening in each circular ring is communicated with the cavities in the two sides of the circular ring, and a multi-stage ring-cavity structure is formed. The interior of the model is composed of a plurality of rings, the rotation angles of the rings in the model can be combined in multiple modes to achieve specific phase regulation and control, and greater flexibility is shown for achieving the stealth function. The multistage ring-cavity coupling model has an excellent stealth effect on vertically incident detection waves, the stealth function of the multi-stage ring-cavity coupling model is suitable for the detection waves incident in a large-range angle, and the multistage ring-cavity coupling model shows a wider application range.

Description

technical field [0001] The invention belongs to the technical field of acoustic stealth materials, and in particular relates to a multi-stage ring-cavity coupling model, an acoustic metasurface material and a reflective stealth structure. Background technique [0002] Stealth is a technology that shields an object so that it does not disturb the external physical field. It has long been a fictional plot in science fiction movies. Because of its extremely important application value in the military field, such as stealth aircraft and submarines, this technology has always been the object of research by researchers from various countries. At present, the method of realizing stealth is mainly based on coordinate transformation. However, the material parameters required to achieve perfect stealth based on this method are not uniformly distributed and extremely anisotropic, which inevitably leads to a too large volume, thus hindering the application of this technical means. Wit...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G10K11/162G10K11/36G10K11/28
CPCG10K11/162G10K11/36G10K11/28
Inventor 翟世龙刘克伦马嘉豪董仪宝王元博冀若楠赵晓鹏
Owner NORTHWESTERN POLYTECHNICAL UNIV
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