Sound scattering by anisotropic metafluids based on two-dimensional sonic crystals

Multiple-scattering theory is here employed to study the scattering of sound by a fluidlike cylinder characterized by an anisotropic mass density tensor. A derivation of the t matrix associated to such acoustic material nonexisting in nature is here comprehensively derived, and the result is employed to study the pressure field produced by plane sound waves impinging the cylinder. It is also shown that an acoustic metamaterial or metafluid can be engineered to exactly match the dynamical properties of the anisotropic fluid by using a circular cluster made of a two-dimensional sonic crystal with a nonisotropic lattice.