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.

Modeled acoustic propagation through a measured large-amplitude nonlinear internal wave in northern South China Sea

2020 ◽  
Author(s):  
Peng Qi
Keyword(s):  
South China Sea ◽  
Internal Waves ◽  
South China ◽  
Large Amplitude ◽  
Sound Propagation ◽  
Transmission Loss ◽  
Northern South China Sea ◽  
Acoustic Propagation ◽  
Propagation Model ◽  
China Sea

<p>Preliminary results are presented from an analysis of modeled mid-frequency sound propagation through a measured large-amplitude nonlinear internal solitary wave, and in-situ measurements of trains of nonlinear internal waves in northern South China Sea (SCS) as well. An acoustic propagation model based on ray theory was utilized to compute the transmission loss (TL) associated with passing the large depression measured internal waves. The TL was computed using the model considering (1) range-dependent and range-independent environmental scenario and (2) for different source and receiver depth configurations. This presentation will propose several interesting aspects of influence of internal waves on acoustic propagation, including "shadow zones", with or without eddy, etc.</p>

scholarly journals A three-dimensional underwater sound propagation model for offshore wind farm noise prediction

2019 ◽  
Vol 145 (5) ◽  
pp. EL335-EL340 ◽  
Author(s):  
Ying-Tsong Lin ◽  
Arthur E. Newhall ◽  
James H. Miller ◽  
Gopu R. Potty ◽  
Kathleen J. Vigness-Raposa
Keyword(s):  
Wind Farm ◽  
Sound Propagation ◽  
Three Dimensional ◽  
Propagation Model ◽  
Offshore Wind ◽  
Noise Prediction ◽  
Underwater Sound ◽  
Offshore Wind Farm

An Efficient Coupled-Mode Formulation for Acoustic Propagation in Inhomogeneous Waveguides

2016 ◽  
Vol 24 (01) ◽  
pp. 1550019
Author(s):  
Chunmei Yang ◽  
Wenyu Luo ◽  
Renhe Zhang ◽  
Liangang Lyu ◽  
Fangli Qiao
Keyword(s):  
Water Column ◽  
Sound Speed ◽  
Sound Propagation ◽  
Acoustic Propagation ◽  
Two Dimensional ◽  
Speed Profile ◽  
Benchmark Problem ◽  
Sound Speed Profile ◽  
Coupled Mode ◽  
Sloping Bottom

The direct-global-matrix coupled-mode model (DGMCM) for sound propagation in range-dependent waveguides was recently developed by Luo et al. [A numerically stable coupled-mode formulation for acoustic propagation in range-dependent waveguides, Sci. China G: Phys. Mech. Astron. 55 (2012) 572–588]. A brief review of the formulation and characteristics of this model is given. This paper extends this model to deal with realistic problems involving an inhomogeneous water column and a penetrable sloping bottom. To this end, the normal mode model KRAKEN is adopted to provide local modal solutions and their associated coupling matrices. As a result, the extended DGMCM model is capable of providing full two-way solutions to two-dimensional (2D) realistic problems with a depth- and range-dependent sound speed profile as well as a penetrable sloping bottom. To validate this model, it is first applied to a benchmark problem of sound propagation in a plane-parallel waveguide with a depth- and range-dependent sound speed profile, and then it is applied to a problem involving both an inhomogeneous water column and a sloping bottom. Comparisons with the analytical solution proposed by DeSanto and with the numerical model COUPLE are also provided, which show that the extended DGMCM model is accurate and efficient and hence can serve as a benchmark for realistic problems of sound propagation in an inhomogeneous waveguide.

The Influence of Positional Parameters on the Effect of a Noise-Jammer Based on Broadband Acoustic Propagation Model

2013 ◽  
Vol 791-793 ◽  
pp. 2043-2047
Author(s):  
Kang Le Miao ◽  
Ri Jie Yang ◽  
Xiong Xiong ◽  
Jian Hui Han
Keyword(s):  
Normal Mode ◽  
Fourier Transformation ◽  
Accurate Result ◽  
Transmission Loss ◽  
Spherical Wave ◽  
Acoustic Propagation ◽  
Propagation Model ◽  
Discrete Fourier Transformation ◽  
Approximate Evaluation ◽  
Long Time

In a long time, the specialists in underwater acoustic countermeasure field were used to get an approximate evaluation of the transmission loss of noise signals by spreading loss equation of spherical wave, which led to results with a low accurateness. Based on normal mode theories and discrete Fourier transformation (DFT), derived the composition and process of the broadband acoustic propagation model. Then the transmission loss could be calculated via this propagation model, which could get a relatively more accurate result. The influence of three key positional parameters, the orientation, distance and depth of the noise-jammer were studied in this paper. The method and conclusions in this paper can provide a reliable foundation for tactical research on noise-jammers.

Measurement of atmospheric sound propagation and meteorological parameters to support development of an acoustic propagation model

2016 ◽  
Vol 140 (4) ◽  
pp. 3260-3260
Author(s):  
Melissa A. Hall ◽  
Teresa Ryan ◽  
Seth Hubbard ◽  
Joseph F. Vignola ◽  
John A. Judge ◽  
...  
Keyword(s):  
Meteorological Parameters ◽  
Sound Propagation ◽  
Acoustic Propagation ◽  
Propagation Model

scholarly journals STUDY OF TRANSMISSION LOSS VARIATION AFFECTED BY INTERNAL TIDES IN THE SEA AREA NORTHEAST OF TAIWAN

2012 ◽  
Vol 20 (01) ◽  
pp. 1250002
Author(s):  
YUAN-YING CHANG ◽  
CHENG-KEN HUANG ◽  
CHI-FANG CHEN ◽  
SEN JAN
Keyword(s):  
Negative Correlation ◽  
Sound Propagation ◽  
Transmission Loss ◽  
Spring Tide ◽  
Mixing Layer ◽  
Internal Tide ◽  
Internal Tides ◽  
Underwater Sound ◽  
Sea Area ◽  
Tide Period

Internal tides can cause density and sound speed fluctuations in the ocean, and the thickness of the mixing layer can fluctuate in short periods of time. This phenomenon affects underwater sound propagation and induces transmission loss variations. In the sea area northeast of Taiwan, regular internal tide activity is observed. The topography and sediment there are also complex, which makes the effect on transmission loss by internal tides even more complicated. This paper studies how transmission loss variation is affected by internal tides in the sea area northeast of Taiwan. The hydrographic fields with influence from the internal tides are provided by an experiment survey on the 4th of September, 2008 and a 3-D tide model. The transmission loss comparison between different thicknesses of the mixing layer in the internal tide fields is shown. Furthermore, the correlation coefficient is calculated and shows that layer depth and transmission loss have a medium to high negative correlation in the upper water column during the summer spring-tide period, and a low to medium negative correlation during the summer neap-tide period.

Effect of Internal Solitary Waves on Underwater Acoustic Propagation

2010 ◽  
Vol 44 (5) ◽  
pp. 10-16
Author(s):  
Peter C. Chu ◽  
Chung-Ping Hsieh
Keyword(s):  
Solitary Waves ◽  
Sound Speed ◽  
Additional Data ◽  
Sound Propagation ◽  
Transmission Loss ◽  
Acoustic Propagation ◽  
Simulation System ◽  
Internal Solitary Waves ◽  
Source Depth ◽  
Acoustic Simulation

AbstractInternal solitary waves (ISWs) were observed on 07:52‐09:36 GMT July 30, 2005, in the Philippine Sea near Taiwan from high-resolution temperature sampling. The effect of ISWs on acoustic propagation was identified using the Navy’s Comprehensive Acoustic Simulation System through comparison between range-independent and range-dependent sound speed profiles. The ISWs enhance the sound propagation slightly (0‐3 dB) in near-range, weaken or enhance the sound propagation (−20 to 20 dB) evidently in midrange, and always weaken the sound propagation (up to −20 dB) in far range. The ISW’s effect on the acoustic propagation varies with sound frequency and sound source depth. This work provides a methodology to anticipate possible errors in transmission loss estimation in an operational framework, if no further additional data are available.

scholarly journals Research on underwater sound source ranging algorithm based on histogram filtering

2021 ◽  
Vol 39 (3) ◽  
pp. 492-501
Author(s):  
Lili Liu ◽  
Jinghua Li ◽  
Xiaoyi Feng ◽  
Haijie Shi ◽  
Xiaobiao Zhang
Keyword(s):  
Prior Knowledge ◽  
Sound Source ◽  
Sound Propagation ◽  
Transmission Loss ◽  
Distance Estimation ◽  
Target Motion ◽  
Horizontal Distance ◽  
Underwater Sound ◽  
Sound Sources ◽  
Shallow Seas

Aiming at the distance measurement of moving sound sources in shallow seas, this paper proposes a method of histogram filtering to realize underwater distance estimation of moving sound sources in shallow seas. The algorithm used the transmission loss, target motion parameter in the sound propagation and receival signal as prior knowledge to updated the state vector of the sound source, so as to realize the distance estimation of the shallow sea sound source, and this paper used SwellEx-96 database for experimental verification. The experimental results shown that: the depth estimating error of moving sound source is small, and when the detected horizontal distance is in the range of 10 km, the maximum range error of the horizontal distance is ±10 m, meanwhile the accuracy of ranging can be improved by improving the prior knowledge of the target motion parameters, which verifies that the histogram filtering algorithm can achieve better ranging for underwater moving targets.

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