阅读说明：本技术 一种基于弧形可调声学超表面的二维地毯式隐身斗篷 (Two-dimensional carpet type cloak based on arc-shaped adjustable acoustic super-surface ) 是由 王艳锋 周红涛 汪越胜 樊世旺 李晓双 付文筱 于 2019-10-22 设计创作，主要内容包括：本发明属于声学技术领域,具体涉及一种基于弧形可调声学超表面的二维地毯式隐身斗篷,采用超表面单胞沿弧形曲线法线方向排列拼接组成,通过转子活动体在弧形定子上、下端盖内旋转角度的变化来改变单胞内部圆环形声通道的长度,进而实现对反射声波相位在0～2π的范围内连续调节。本发明提供的地毯式隐身斗篷可通过设置弧形超表面内部转子活动体阵列的旋转角实现在不同频率和不同入射角度下的地毯式隐身,达到实时调节的目的,同时所具有的弧形外形曲线结构可为制造贴近任意物体表面的弧形隐身斗篷提供重要的理论基础。(The invention belongs to the technical field of acoustics, and particularly relates to a two-dimensional carpet type cloak based on an arc-shaped adjustable acoustic super surface, which is formed by arranging and splicing super surface unit cells along the normal direction of an arc-shaped curve, wherein the length of a circular sound channel in the unit cells is changed through the change of the rotating angle of a rotor movable body in an upper end cover and a lower end cover of an arc-shaped stator, so that the phase of a reflected sound wave is continuously adjusted within the range of 0-2 pi. The carpet type cloak provided by the invention can realize carpet type cloak under different frequencies and different incidence angles by setting the rotation angle of the arc-shaped super-surface internal rotor movable body array, so as to achieve the purpose of real-time adjustment, and meanwhile, the arc-shaped curve structure can provide an important theoretical basis for manufacturing the arc-shaped cloak close to the surface of any object.)

1. The utility model provides a two-dimentional carpet formula stealthy cape based on super surface of adjustable acoustics of arc which characterized in that: the surface is surpassed to the adjustable acoustics of arc including a plurality of the same, and is a plurality of the adjustable acoustics of arc surpasses the surface and constitutes a cylindricality stealth cloak in the concatenation of the direction array that is on a parallel with the horizon, the appearance curve of stealth cloak adopts the arc structure of axial symmetry, at top smooth connection, tangent with the horizon level in the left and right sides, arc transition smooth connection between stealth cloak and the horizon.

2. The two-dimensional carpet stealth cloak based on an arcuate tunable acoustic hypersurface of claim 1, wherein: the arc-shaped adjustable acoustic super surface is formed by arranging and splicing a plurality of super surface unit cells along the normal direction of an arc-shaped curve.

3. The two-dimensional carpet stealth cloak based on an arcuate tunable acoustic hypersurface of claim 2, wherein: the whole super-surface unit cell is of a cuboid structure.

4. The two-dimensional carpet stealth cloak based on an arc-shaped adjustable acoustic super surface as claimed in claim 3, wherein: the super-surface unit cell comprises a stator upper end cover, a stator lower end cover and a rotor movable body, wherein the stator upper end cover and the stator lower end cover are provided with sound channel inlets at the center of the top, sound channels and grooves are arranged at the center of the inside, fan-shaped blade-shaped connecting pieces are fixed on the left side of the inside, and countersunk holes are formed in the upper surface and the lower surface of the stator.

5. The two-dimensional carpet stealth cloak based on an arc-shaped adjustable acoustic super surface of claim 4, wherein: the arc-shaped adjustable acoustic super-surface comprises an arc-shaped stator upper end cover framework, a rotor moving body array and an arc-shaped stator lower end cover framework, wherein the rotor moving body array is accommodated between the arc-shaped stator upper end cover framework and the arc-shaped stator lower end cover framework.

6. The two-dimensional carpet stealth cloak based on an arc-shaped adjustable acoustic hypersurface according to claim 5, wherein: the rotor movable body is used for rotating between the arc-shaped stator upper end cover framework and the arc-shaped stator lower end cover framework.

7. The two-dimensional carpet stealth cloak based on an arc-shaped adjustable acoustic hypersurface according to claim 6, characterized in that: the rotating angle range of the rotor moving body is 0-330 degrees.

8. The two-dimensional carpet stealth cloak based on an arc-shaped adjustable acoustic super surface of claim 4, wherein: the groove is used for placing the rotor movable body; a first through hole is formed in the center of the groove; the counter bores are used for placing bolts and nuts.

9. The two-dimensional carpet stealth cloak based on an arc-shaped adjustable acoustic super surface of claim 4, wherein: the rotor movable body comprises a fan-shaped blade-shaped cylinder and a cylinder, the fan-shaped blade-shaped cylinder is matched with the upper end cover of the stator and the inner sound channel of the lower end cover of the stator, and the cylinder is matched with the groove; and a second through hole is formed in the center of the rotor movable body and is coaxial with the first through hole.

10. The two-dimensional carpet stealth cloak based on an arcuate tunable acoustic hypersurface of claim 9, wherein: the first through hole is connected with the second through hole through a bolt.

Technical Field

The invention belongs to the technical field of acoustics, and particularly relates to a two-dimensional carpet type cloak based on an arc-shaped adjustable acoustic super surface.

Background

The super surface is a layered structure material with the thickness within a sub-wavelength scale range, and the propagation characteristic of waves can be regulated and controlled through a fine structure in the super surface. The super-surface appears in the electromagnetic field at the earliest time, gradually expands to the acoustic field in recent years, and vast technologists realize a series of novel acoustic phenomena such as abnormal reflection, random focusing, self-bending, vector wave beams, traveling wave-to-evanescent wave, enhanced absorption, phantom image, carpet stealth and the like by utilizing the acoustic super-surface from the aspects of theoretical analysis, numerical simulation, experimental verification and the like. Compared with the traditional acoustic device and acoustic metamaterial, the acoustic super surface has excellent regulation and control capability on sound waves, has the advantages of flexible function regulation, high structural variability, small geometric dimension and the like, and can be widely applied to the aspects of medical monitoring, environmental noise reduction, aerospace, national defense and military and the like.

The carpet type cloaking is a cloak covering on the ground, can simulate the reflection of the ground to sound waves, effectively confuses the active detection of objects below the cloak by external sonar, and thus achieves the purpose of hiding target objects. Carpet hiding has attracted a great deal of scholars' research in recent years as a very important acoustics physical effect. However, in the reported two-dimensional cylindrical carpet type cloaking structure, most cloak adopts a triangular structural design, which causes unnecessary scattering at the intersection of two sides of the triangle above the cloak, thereby reducing the cloaking performance of the cloak. In addition, after being processed and manufactured, the carpet type cloak can only play a good cloak effect in a small range under the designed target frequency and incidence angle, if the cloak is required to play a role under different frequencies and different incidence angles, a plurality of cloaks need to be manufactured, and the adjustability is lacked, so that the waste of manpower and resources is caused. Therefore, it is very important how to adjust a cloak in real time according to the actual working condition to ensure that the cloak can better work in a wider frequency range and at different incident angles.

Disclosure of Invention

The invention aims to: aiming at the defects of the prior art, the two-dimensional carpet type cloak based on the arc-shaped adjustable acoustic super surface is provided, and particularly relates to the two-dimensional carpet type cloak constructed by two arc-shaped adjustable super surfaces, namely an arc-shaped adjustable acoustic super surface and an elliptical arc-shaped adjustable super surface. The carpet type cloak can realize continuous adjustment of the cloak sound wave frequency and the incident angle, and meanwhile, the arc-shaped super surface structure comprises concave and convex arcs or elliptical arcs, so that a key research basis can be provided for designing the carpet type cloak which is close to the shape curve of any object.

In order to achieve the purpose, the invention adopts the following technical scheme:

the utility model provides a two-dimentional carpet formula cloak that stealthy cape based on surface is surpassed to adjustable acoustics of arc, includes that the adjustable acoustics of a plurality of the same arcs surpass the surface, and is a plurality of the adjustable acoustics of arc surpasses the surface and splices the stealthy cape of constituteing a cylindricality in the direction array that is on a parallel with the ground plane, the appearance curve of stealthy cape adopts axisymmetric arc structure, at top smooth connection, tangent with the ground plane level in the left and right sides, arc transition smooth connection between stealthy cape and the ground plane. The structural design enhances the stealth effect, and the stealth cloak achieves the acoustic carpet type stealth effect.

The arc-shaped adjustable acoustic super surface is formed by arranging and splicing a plurality of super surface unit cells along the normal direction of an arc-shaped curve. In practical application, a plurality of super-surface unit cells can be flexibly arranged according to the working requirement so as to adapt to different application occasions.

As an improvement of the two-dimensional carpet type cloak based on the arc-shaped adjustable acoustic super surface, the whole super surface unit cell is of a cuboid structure. The structural design increases the working stability of the whole structure.

The two-dimensional carpet type cloak based on the arc-shaped adjustable acoustic super surface comprises an upper stator end cover, a lower stator end cover and a rotor movable body, wherein the upper stator end cover and the lower stator end cover are respectively provided with an acoustic channel inlet at the center of the top, an acoustic channel and a groove are respectively arranged at the center of the interior, fan-shaped blade-shaped connecting pieces are respectively fixed on the left side of the interior, and countersunk holes are respectively arranged on the upper surface and the lower surface of the interior. The structural design is beneficial to enhancing the stealth effect of the whole structure.

The two-dimensional carpet type cloaking cloak based on the arc-shaped adjustable acoustic super surface is an improvement, the arc-shaped adjustable acoustic super surface comprises an arc-shaped stator upper end cover framework, a rotor movable body array and an arc-shaped stator lower end cover framework, and the rotor movable body array is accommodated between the arc-shaped stator upper end cover framework and the arc-shaped stator lower end cover framework. In practical application, the continuously adjustable acoustical carpet type stealth function is realized by adopting the change of the rotating angles of the rotor moving body arrays in the upper end cover framework and the lower end cover framework of the arc-shaped stator.

As an improvement of the two-dimensional carpet type cloak based on the arc-shaped adjustable acoustic super surface, the rotor movable body is used for rotating between the upper end cover framework of the arc-shaped stator and the lower end cover framework of the arc-shaped stator. The structural design is beneficial to realizing the adjustment of the stealth function.

As an improvement of the two-dimensional carpet type cloak based on the arc-shaped adjustable acoustic super surface, the rotating angle range of the rotor movable body is 0-330 degrees. The structural design realizes phase compensation of all points of the arc-shaped adjustable acoustic super surface, so that incident sound waves have the same reflected wave front characteristics on the arc-shaped adjustable acoustic super surface and a ground plane, and the purpose of sound wave blanket type stealth is achieved.

As an improvement of the two-dimensional carpet type cloak based on the arc-shaped adjustable acoustic super surface, the groove is used for placing the rotor movable body; a first through hole is formed in the center of the groove; the counter bores are used for placing bolts and nuts. The structural design is beneficial to reducing the volume of the whole structure.

As an improvement of the two-dimensional carpet type cloak based on the arc-shaped adjustable acoustic super surface, the rotor movable body comprises a fan-shaped blade-shaped cylinder and a cylinder, the fan-shaped blade-shaped cylinder is matched with the upper end cover of the stator and the acoustic channel inside the lower end cover of the stator, and the cylinder is matched with the groove; and a second through hole is formed in the center of the rotor movable body and is coaxial with the first through hole. This design facilitates a flexible adjustment of the stealth effect.

As an improvement of the two-dimensional carpet type cloak based on the arc-shaped adjustable acoustic super surface, the first through hole and the second through hole are connected through a bolt. The structure design is favorable for fixing the position of the rotor moving body and flexibly adjusting the rotor moving body according to the working requirement.

Compared with the prior art, the beneficial effects of this application are: the carpet type cloak can realize continuous adjustment of the cloak sound wave frequency and the incident angle, and meanwhile, the arc-shaped super surface structure comprises concave and convex arcs or elliptical arcs, so that a key research basis can be provided for designing the carpet type cloak which is close to the shape curve of any object.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention and not to limit the invention. In the drawings:

fig. 1 is a schematic structural diagram of a two-dimensional carpet type cloak based on an arc-shaped adjustable acoustic super surface according to an embodiment of the present invention;

FIG. 2 is a schematic structural view of an arcuate tunable acoustic metasurface provided in an embodiment of the present invention;

FIG. 3 is a schematic diagram of a super-surface unit cell according to an embodiment of the present invention;

FIG. 4 is a schematic structural diagram of an equivalent cross-section of a Supersurface unit cell provided in an embodiment of the present invention in the x-z plane;

fig. 5 is one of schematic structural diagrams of an equivalent cross section of a two-dimensional carpet hidden cloak formed by an arc-shaped adjustable acoustic super surface in an x-z plane according to an embodiment of the present invention;

FIG. 6 is a schematic diagram illustrating a carpet hiding effect when an incident acoustic wave is a plane wave, an acoustic frequency is 3.2kHz, and an incident angle is 0 degree (vertical incidence along a negative z-axis direction) according to an embodiment of the present invention;

FIG. 7 is a schematic diagram illustrating the carpet hiding effect when the incident sound wave is a plane wave, the sound wave frequency is 5.2kHz, and the incident angle is 0 degree (vertical incidence along the negative direction of the z-axis) according to the embodiment of the present invention;

FIG. 8 is a schematic diagram illustrating the carpet hiding effect when the incident acoustic wave is a plane wave, the acoustic wave frequency is 3.2kHz, and the incident angle is 35 degrees (35 degrees oblique incidence is included in the negative direction of the z-axis) according to the embodiment of the present invention;

fig. 9 is one of schematic equivalent cross-sectional structural views on the x-z plane of a two-dimensional carpet-type cloak composed of an elliptical arc-shaped adjustable acoustic super surface provided for the second embodiment of the present invention;

FIG. 10 is a schematic diagram of the carpet hiding effect when the incident sound wave is a plane wave, the sound wave frequency is 3.2kHz, and the incident angle is 0 degree (vertical incidence along the negative direction of the z-axis);

FIG. 11 is a schematic diagram illustrating the carpet hiding effect when the incident sound wave is a plane wave, the sound wave frequency is 5.2kHz, and the incident angle is 0 degree (vertical incidence along the negative direction of the z-axis) according to the embodiment of the present invention;

FIG. 12 is a schematic diagram illustrating the carpet hiding effect when the incident acoustic wave is a plane wave, the acoustic wave frequency is 3.2kHz, and the incident angle is 35 degrees (35 degrees oblique incidence is included in the negative direction of the z-axis) according to the embodiment of the present invention;

FIG. 13 is a schematic exploded view of FIG. 3;

fig. 14 is a second schematic structural view of an equivalent cross section of a two-dimensional carpet-type cloak composed of an arc-shaped adjustable acoustic super surface in an x-z plane according to an embodiment of the present invention;

fig. 15 is a second schematic structural view of an equivalent cross-section of a two-dimensional carpet-type cloak composed of an elliptical arc-shaped adjustable acoustic super-surface according to a second embodiment of the present invention on the x-z plane.

Wherein: 1-ground plane; 2-cloaking cloak; 21-curved adjustable acoustic metasurface; 211-arc stator upper end cover framework; 212-rotor moving body array; 213-arc stator lower end cover framework; 214-bolt and nut assembly; 3-stealth objects; 4-unit cell; 41-a nut; 42-stator upper end cover; 43-rotor moving body; 44-stator lower end cover; 45-bolt.

Detailed Description

As used in the specification and in the claims, certain terms are used to refer to particular components. As one skilled in the art will appreciate, manufacturers may refer to a component by different names. This specification and claims do not intend to distinguish between components that differ in name but not function. In the following description and in the claims, the terms "include" and "comprise" are used in an open-ended fashion, and thus should be interpreted to mean "include, but not limited to. "substantially" means within an acceptable error range, within which a person skilled in the art can solve the technical problem to substantially achieve the technical result.

In the description of the present invention, it is to be understood that the terms "upper", "lower", "front", "rear", "left", "right", "horizontal", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience in describing the present invention and simplifying the description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention.

In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

The present invention will be described in further detail below with reference to the accompanying drawings, but the present invention is not limited thereto.