Numerical study of beam shape adaptation by anisotropic disk covering transducer or metamaterial

Abstract

Metamaterials are intensely explored for their capabilities to modify sound beams. In addition to frequency filtering, acoustic lenses offer intriguing possibilities for shaping sound beams. For the time being, the versatility of metamaterials remains limitless. In beam-shape adaptation, however, their complexity suggests that manufacturers of transducers could benefit from combining metamaterials with more conventional materials. This paper investigates the transmission of a circumscribed beam through a stratum of anisotropic material to examine the change in beam shape after transmission. The incident sound is presumed to originate from a conventional transducer, possibly coated with a metamaterial to modify the sound field, before being transmitted through the anisotropic layer. Different incident beam shapes, such as conical-like, Gaussian, and pillar beams, are investigated. While the results are not exhaustive, they demonstrate the beam shape’s adaptability.