Moving sound source with an arbitrary trajectory in the two-dimensional finite-difference time-domain method

Abstract

In this paper, a moving sound source with an arbitrary trajectory is implemented using the finite-difference time-domain (FDTD) method. Two methods are proposed for implementing a moving-point sound source in the FDTD method, in which physically valid analysis is possible, including that of the Doppler effect. One method is the direct method and the other is the convolution method. We produce formulations and perform numerical experiments for a two-dimensional sound field, and the accuracies of the two proposed methods are compared. It is confirmed that both methods can be applied to a moving sound source, including the Doppler effect, and that the two methods have almost the same accuracy. It is found that the convolution method has advantages in that the source waveform and speed of movement can be freely changed at the time of convolution.