Rayleigh angle incident ultrasonic beam shape design influence on reflected beam

Abstract

Current evolutions in transducer design, such as phased arrays, but more importantly, metamaterials-based acoustic lenses, potentially enable generating specific beam shapes earlier unconsidered. It is known that the Schoch effect, when a bounded incident beam on a submerged solid reflects at the Rayleigh angle, depends on the beam width and the frequency. This work numerically explores the consequence of the shape of such beams on the Schoch effect and invites further experimental work. The study investigates square shapes and beams with exponential flanks compared to Gaussian reference profiles and incorporates diffraction upon sound propagation to resemble reality better. It is shown that stunning differences occur depending on the beam shape, particularly for square beams.