Autori: Ligia Munteanu, Veturia Chiroiu
Editorial: New Journal of Physics, 13, 8, p.083031, 2011.
Transformation acoustics opens a new avenue towards the design
of acoustic metamaterials, which are materials engineered at the subwavelength
scale in order to mimic the parameters in wave equations. The design of the
acoustic cloaking is based on the property of equations being invariant under a
coordinate transformation, i.e. a specific spatial compression is equivalent to a
variation of the material parameters in the original space. In this paper, the sound
invisibility performance is discussed for spherical cloaks. The original domain
consists of alternating concentric layers made from piezoelectric ceramics and
epoxy resin, following a triadic Cantor sequence. The spatial compression,
obtained by applying the concave-down transformation, leads to an equivalent
domain with an inhomogeneous and anisotropic distribution of the material
Cuvinte cheie: transformational acoustic, spherical acoustic cloak, metamaterial.