# Simulation of 3D elasto-acoustic wave propagation based on a Discontinuous Galerkin Spectral Element method

## TL;DR

This paper introduces a Discontinuous Galerkin Spectral Element method for simulating 3D coupled elasto-acoustic wave propagation, demonstrating its accuracy and applicability through convergence tests and realistic scenario simulations.

## Contribution

It presents a novel 3D DGSE discretization for coupled elasto-acoustic problems with a symmetric formulation and assesses its performance on complex scenarios.

## Key findings

- The method achieves high convergence accuracy.
- It effectively simulates Scholte waves and wave scattering.
- Numerical results validate the approach's robustness.

## Abstract

In this paper we present a numerical discretization of the coupled elasto-acoustic wave propagation problem based on a Discontinuous Galerkin Spectral Element (DGSE) approach in a three-dimensional setting. The unknowns of the coupled problem are the displacement field and the velocity potential, in the elastic and the acoustic domains, respectively, thereby resulting in a symmetric formulation. After stating the main theoretical results, we assess the performance of the method by convergence tests carried out on both matching and non-matching grids, and we simulate realistic scenarios where elasto-acoustic coupling occurs. In particular, we consider the case of Scholte waves and the scattering of elastic waves by an underground acoustic cavity. Numerical simulations are carried out by means of the code SPEED, available at http://speed.mox.polimi.it.