Normal‐mode calculations of underwater sound propagation from directional sources

1974 ◽  
Vol 55 (S1) ◽  
pp. S44-S45
Author(s):  
A. J. Haug ◽  
R. D. Graves ◽  
H. Überall
Keyword(s):  
Normal Mode ◽  
Sound Propagation ◽  
Underwater Sound ◽  
Normal Mode Calculations

scholarly journals Underwater Sound Propagation Modeling in a Complex Shallow Water Environment

2021 ◽  
Vol 8 ◽  
Author(s):  
Tiago C. A. Oliveira ◽  
Ying-Tsong Lin ◽  
Michael B. Porter
Keyword(s):  
Shallow Water ◽  
Normal Mode ◽  
Sound Propagation ◽  
Long Island ◽  
Water Environment ◽  
Long Island Sound ◽  
Underwater Sound ◽  
Shallow Water Environment ◽  
3D Effects ◽  
Island Sound

Three-dimensional (3D) effects can profoundly influence underwater sound propagation in shallow-water environments, hence, affecting the underwater soundscape. Various geological features and coastal oceanographic processes can cause horizontal reflection, refraction, and diffraction of underwater sound. In this work, the ability of a parabolic equation (PE) model to simulate sound propagation in the extremely complicated shallow water environment of Long Island Sound (United States east coast) is investigated. First, the 2D and 3D versions of the PE model are compared with state-of-the-art normal mode and beam tracing models for two idealized cases representing the local environment in the Sound: (i) a 2D 50-m flat bottom and (ii) a 3D shallow water wedge. After that, the PE model is utilized to model sound propagation in three realistic local scenarios in the Sound. Frequencies of 500 and 1500 Hz are considered in all the simulations. In general, transmission loss (TL) results provided by the PE, normal mode and beam tracing models tend to agree with each other. Differences found emerge with (1) increasing the bathymetry complexity, (2) expanding the propagation range, and (3) approaching the limits of model applicability. The TL results from 3D PE simulations indicate that sound propagating along sand bars can experience significant 3D effects. Indeed, for the complex shallow bathymetry found in some areas of Long Island Sound, it is challenging for the models to track the interference effects in the sound pattern. Results emphasize that when choosing an underwater sound propagation model for practical applications in a complex shallow-water environment, a compromise will be made between the numerical model accuracy, computational time, and validity.

Correlation between the fluctuations of underwater sound propagation and shelfbreak oceanography

2021 ◽  
Vol 150 (4) ◽  
pp. A157-A157
Author(s):  
Ying-Tsong Lin ◽  
Glen Gawarkiewicz ◽  
Andone C. Lavery ◽  
Weifeng G. Zhang ◽  
J Michael Jech ◽  
...  
Keyword(s):  
Sound Propagation ◽  
Underwater Sound

Flow-dependent modeling of acoustic propagation based on DG-FEM method

2021 ◽  
Author(s):  
Zichen Wang ◽  
Jian Xu ◽  
Xuefeng Zhang ◽  
Can Lu ◽  
Kangkang Jin ◽  
...  
Keyword(s):  
Sound Propagation ◽  
Transmission Loss ◽  
Acoustic Propagation ◽  
Water Area ◽  
Current Speed ◽  
Propagation Model ◽  
Propagation Loss ◽  
Two Dimensional ◽  
Underwater Sound ◽  
Ocean Environment

AbstractThis paper proposes a two-dimensional underwater sound propagation model using the Discontinuous Galerkin Finite Element Method (DG-FEM) to investigate the influence of current on sound propagation. The acoustic field is calculated by the convected wave equation with the current speed parameter. Based on the current speed data from an assimilation model, a two-dimensional coupled acoustic propagation model in the Fram Strait water area is established to observe the variability in propagation loss under different seasonal velocities in the real ocean environment. The transmission loss and signal time structure are examined. The results obtained in different source frequencies are also compared. It appears that the current velocity, time and range variation all have an effect on underwater sound propagation.

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