Generalization and stabilization of exact scattering solutions for spherical symmetric scatterers

TL;DR

This paper extends a high-fidelity acoustic scattering model for multilayered elastic spheres by introducing a scaling strategy, new boundary conditions, and excitations, thereby improving stability, frequency range, and generality of the solutions.

Contribution

The work introduces a scaling strategy and new boundary conditions for a scattering model, enabling broader frequency use and more general layering configurations.

Findings

Mitigates overflow issues, expanding frequency range.

Validates model against reference solutions with various examples.

Includes new boundary conditions and excitations for enhanced modeling.

Abstract

In a previous work the authors described a fast high-fidelity computer model for acoustic scattering from multi-layered elastic spheres. This work is now extended with a scaling strategy significantly mitigating the problem of overflow and thus expanding the useful frequency range of the model. Moreover, new boundary conditions and loads are implemented. Most important are the fluid-fluid and solid-solid couplings, which allow a completely general layering of the scattering object. Sound hard and sound soft boundary conditions are implemented for solids and fluids respectively. In addition to the existing acoustic excitation, mechanical excitation in the form of point-excitation and surface excitation are implemented. Attenuation in the form of hysteresis damping as well as viscous fluid layers are also included. Several numerical examples are included, with the purpose of validating the code against existing reference solutions. The examples include air bubbles, a coated steel shell and a point-exited steel shell.