Researches on very low frequency acoustic signal propagation characteristics in different shallow elastic wedge bottoms

¹ Institute of Naval Architecture and Mechanical-electrical Engineering, Zhejiang Ocean University, 316022 Zhoushan, Zhejiang, China
² Institute of Marine Science and Technology, Zhejiang Ocean University, 316022, Zhoushan, Zhejiang, China
³ Acoustic Science and Technology Laboratory, Harbin Engineering University, 150001, Harbin, Heilongjiang, China

^* Corresponding author: zhuhanhao@zjou.edu.cn

Abstract

Targeted at the issue of extremely low-frequency (<100Hz) acoustic propagation in complex shallow elastic bottom environments. The influence law of different complex elastic bottoms on the acoustic signal propagation at very low frequency by acoustic energy flux has been analyzed with the simulation, which is based on the finite element method. The elastic bottoms which have been studied are the shallow horizontal elastic bottom, and the up-sloping and the down-sloping elastic bottom. The results show that the acoustic signal propagating in the up-sloping and down-sloping elastic bottom environments is more complex than that propagating in the horizontal elastic bottom, and the acoustic energy leaking into those elastic bottoms has very different influence on the acoustic signal propagation, especially in the up-sloping bottom.