Achieving acoustic cloak by using compressible background flow

Zhang Ruo-Yang¹, Zhao Qing², Ge Mo-Lin^{1, 2, †,}

The angular distributions of differential scattering cross sections of unideal cloaks at the wave lengths: (a) λ = 0.5a, (b) λ = a, (c) λ = 2a. (d) The total scattering cross section versus wave length. In each figure, the black curve denotes the scatter of a ball with unit radius and hard boundary, the red, blue, orange, green curves correspond to the unideal cloaks of δ = 0.1, 0.05, 0.02, 0.01 respectively.