Two-dimensional carpet-type invisible cloak based on arc adjustable acoustic metasurface

Abstract

The invention relates to the field of acoustic technology, particularly relates to a two-dimensional carpet-type invisible cloak based on an arc adjustable acoustic metasurface, and is formed by arranging and splicing metasurface unit cells along the normal direction of the arc curve. The length of the circular acoustic channel in the unit cell is changed by changing the rotation angle of the rotor movable body in the upper and lower end covers of the arc stator, so that the phase position of the reflected sound wave is continuously adjusted between 0-2 pi. The carpet-type invisible cloak provided by the invention realizes carpet-type invisibility under different frequencies and different incident angles by arranging the rotation angle of the rotor movable body in the arc metasurface, so as to achieve the purpose of the real-time adjustment. And simultaneously, the arc-shaped curve structure provides important theoretical basis for manufacturing the arc invisible cloak capable of beingclose to the surface of any object.

Description

technical field [0001] The invention belongs to the technical field of acoustics, and in particular relates to a two-dimensional carpet-type invisibility cloak based on an arc-shaped adjustable acoustic metasurface. Background technique [0002] Metasurface refers to a kind of layered structure material whose thickness is in the range of subwavelength scale, and the wave propagation characteristics can be adjusted through its internal microstructure. Metasurfaces first appeared in the field of electromagnetics, and have gradually expanded to the field of acoustics in recent years. A large number of scientific and technological workers have used acoustic metasurfaces to realize a series of novel acoustic phenomena from the aspects of theoretical analysis, numerical simulation and experimental verification, such as abnormal Reflection, arbitrary focus, self-bending, vector beam, traveling wave to evanescent wave, enhanced absorption, phantom and carpet stealth, etc. Compared ...

AI Technical Summary

Problems solved by technology

However, in the reported two-dimensional cylindrical carpet stealth structure, most of the invisibility cloaks adopt a triangular structure design, which will cause unnecessary scattering at the intersection of the two sides of the triangle above the cloak, thereby reducing the stealth performance of the cloak

In addition, these carpet-style invisibility cloaks can only achieve a good stealth effect in a small range under the designed target frequency and angle of incidence after processing and manufacturing. , it is necessary to manufacture multiple invisibility cloaks, lack of adjustability, resulting in waste of manpower and resources

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