Achieving acoustic cloak by using compressible background flow

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

Constitutive relationship between pressure P and density ρ fitted by 5 order Virial expansion (blue curve). The red dotted curve denotes the required constitutive relationship corresponding to the unideal cloak of δ = 0.1 constructed by the transformation function Eq. (12) with n = 4.