Abstract:
A modified finite-difference time-domain (FDTD)
method is described in this paper. The absorption coefficient
which is frequency-dependent is considered, and it is used to
compute broadband acoustic scattering model of underwater
complex object. The perfectly matched layer (PML) absorbing
boundary condition (ABC) is applied to this work. Considering
computation and accuracy comprehensively, PML boundary
layer number and the attenuation coefficient is set at proper
values. Computer Graphics are applied to mesh-generating of
the irregular object. A pulse of LFM signal is used to simulate
wide-band acoustic scattering field of a circle in 2D and a
complex object in 3D. And the scattered acoustic pressure
waveforms of some certain points are computed in the
calculation field. Results obtained from simulation confirm the
high accuracy of the proposed method.
