Modelling elastic wave propagation using the k-Wave MATLAB Toolbox

Abstract

A new model for simulating elastic wave propagation using the open-source k-Wave MATLAB Toolbox is described. The model is based on two coupled first-order equations describing the stress and particle velocity within an isotropic medium. For absorbing media, the Kelvin-Voigt model of viscoelasticity is used. The equations are discretised in 2D and 3D using an efficient time-stepping pseudospectral scheme. This uses the Fourier collocation spectral method to compute spatial derivatives and a leapfrog finite-difference scheme to integrate forwards in time. A multi-axial perfectly matched layer (M-PML) is implemented to allow free-field simulations using a finite-sized computational grid. Acceleration using a graphics processing unit (GPU) is supported via the MATLAB Parallel Computing Toolbox. An overview of the simulation functions and their theoretical and numerical foundations is described.