Interactions of a short-pulsed plane acoustic wave with complex rigid objects: a numerical study

Abstract

In this paper, we numerically study interactions of a short-pulsed plane acoustic wave with complex rigid objects by solving the linearized Euler equations. For the study, our numerical approach implements an immersed boundary method to satisfy the no-penetration condition on the surface of rigid objects, together with a fully-explicit staggered-grid finitedifference time-domain method having perfectly matched layers. First, we validate our approach for acoustic wave scattering by a circular cylinder, a well-known benchmark problem. Subsequently, we extend our simulations to two representative problems, namely interactions with a circular cylinder and a plano-concave lens which are of paramount interest in terms of acoustic force and acoustic focusing, respectively. Our simulations allow us to better understand the main mechanism of propagation, reflection, and scattering of acoustic waves as a result of interaction with rigid objects. In addition, the effects of pulse width on the interactions are closely investigated.