Acoustic wave propagation in depth-evolving sound-speed field using the lattice Boltzmann method.

This article focuses on investigating sound wave propagation in deep-sea low-sound-speed channels using the lattice Boltzmann method (LBM), emphasizing the effects of depth-dependent sound speed variations. The study validates the LBM model through one- and two-dimensional simulations, including acoustic reflections on smooth and rough surfaces and wave scattering by cylinders, before analyzing sound propagation around submarines (suboff) in both two- and three-dimensional settings. Key findings reveal that sound waves at depths other than the lowest sound speed are deflected downward, while waves originating within the low-sound-speed channel converge and exhibit total internal reflection below a critical angle, preserving signal amplitude over long distances. Additionally, submarines cruising within the low-sound-speed channel experience asymmetric and attenuated acoustic fields, leading to a silencing effect important for stealth, and the channel enhances signal transmission around obstacles, facilitating communication among multiple submarines.