Numerical Simulation of Acoustic Imaging Using a Combination of Finite Difference Time Domain and Boundary Integral Equation Methods

Abstract

A numerical method based on the combination of the finite difference time domain (FDTD) and boundary integral equation (BIE) methods is proposed and applied to the simulation of acoustic imaging. The sound field is divided into two domains; one is the small domain, which is solved by the FDTD method to include wave properties such as diffraction, and the other is the large domain, which is analyzed by the boundary integral equation method to obtain a response at the required point to avoid numerical dispersion error. The reflected waves from the targets are calculated by the Kirchhoff boundary integral equation method. Some numerical demonstrations are carried out for a two-dimensional sound fields in water. It is confirmed that the combination method causes very little numerical dispersion error and is suitable for the simulation of large scale acoustic imaging.