Sanchis L, García-Chocano V M, Llopis-Pontiveros R, Climente A, Martínez-Pastor J, Cervera F, Sánchez-Dehesa J
UMDO (Unidad Asociada al CSIC-IMM), Instituto de Ciencia de Materiales, Universidad de Valencia, P.O. Box 22085, 46071 Valencia, Spain.
Wave Phenomena Group, Universitat Politècnica de València, Camino de Vera s.n. (Edificio 7F), ES-46022 Valencia, Spain.
Phys Rev Lett. 2013 Mar 22;110(12):124301. doi: 10.1103/PhysRevLett.110.124301. Epub 2013 Mar 20.
This Letter presents the design, fabrication, and experimental characterization of a directional three-dimensional acoustic cloak for airborne sound. The cloak consists of 60 concentric acoustically rigid tori surrounding the cloaked object, a sphere of radius 4 cm. The major radii and positions of the tori along the symmetry axis are determined using the condition of complete cancellation of the acoustic field scattered from the sphere. They are obtained through an optimization technique that combines genetic algorithm and simulated annealing. The scattering cross section of the sphere with the cloak, which is the magnitude that is minimized, is calculated using the method of fundamental solutions. The low-loss fabricated cloak shows a reduction of the 90% of the sphere scattering cross section at the frequency of 8.55 kHz.
本文介绍了一种用于空气传播声音的定向三维声学隐身衣的设计、制造和实验表征。该隐身衣由围绕被隐身物体（半径为4厘米的球体）的60个同心声学刚性环面组成。环面的主半径和沿对称轴的位置是根据球体散射声场完全抵消的条件确定的。它们是通过结合遗传算法和模拟退火的优化技术获得的。使用基本解方法计算带有隐身衣的球体的散射截面，这是被最小化的量。制造出的低损耗隐身衣在8.55千赫兹频率下使球体散射截面降低了90%。
