Modeling and Characterization of Bio-Inspired Hydro-Acoustic Sensor

2015 ◽  
Vol 137 (3) ◽  
Author(s):  
Jin-Hyuk Lee ◽  
Per G. Reinhall ◽  
Hwan-Sik Yoon

A biomimetic miniature underwater acoustic sensor is proposed and analyzed for the measurement of directivity of underwater sound propagation. Unlike a hydrophone array, which detects propagation direction by the arrival time of sound waves, this novel sensor is based on a mechanically coupled mechanism, which amplifies the time delay of the arriving sound wave. In this paper, a mathematical model of the sensor is developed based on the finite element (FE) modeling technique, and it is used to study performance characteristics of the sensor. Effects of the fluid–structure interaction are examined through simulation of the sensor model and the results are compared with those obtained by a full scale FE model developed in a commercial software package.

2018 ◽  
Vol 8 (2) ◽  
pp. 25-39
Author(s):  
Mohamed Elhadi Rahmani ◽  
Abdelmalek Amine ◽  
Reda Mohamed Hamou

Sound Navigation and Ranging (Sonar) is underwater sound detection used in boats or submarines to navigate, communicate with or detect objects under the surface of water based on sound propagation. It is helpful for exploring and mapping the ocean because sound waves travel farther in the water than do radar and light waves. Based on signal data obtained from sonar, this article presents a new heuristic approach inspired from black holes' phenomenon proposed by Schwarzschild, it has been applied to the classification sonar returns from two undersea targets, a metal cylinder and a similarly-shaped rock. Results are very satisfied (almost 83% of accuracy) compared to original works. in manner that encourage to keep working on paper, the main idea of this article is to benefit from the power of nature to solve complex problems in computer science


2021 ◽  
Vol 9 (9) ◽  
pp. 1035
Author(s):  
Jiaqi Liu ◽  
Shengchun Piao ◽  
Minghui Zhang ◽  
Shizhao Zhang ◽  
Junyuan Guo ◽  
...  

Oceanic fronts involved by ocean currents led to strong gradients of temperature, density and salinity, which have significant effects on underwater sound propagation. This paper focuses on the impact of the oceanic front on three-dimensional underwater sound propagation. A joint experiment of ocean acoustic and physical oceanography at the western North Pacific fronts is introduced. The measurement data for sound waves passed through the oceanic front is processed. The results are analysed and compared with the numerical simulation. It was found that transmission loss presented some difference when the source was located in the front centre and sound waves propagated towards water mass on opposite sides of the front centre. And when the sound field is excited by the underwater explosion at a depth of 200 m, the effects of the horizontal refraction cannot be neglected. On the other hand, the transmission loss for sound pressure fell sharply and rose rapidly at the side of cold water masses.


2015 ◽  
Vol 15 (3) ◽  
pp. 1559-1566 ◽  
Author(s):  
Mohamad Faizal Abd Rahman ◽  
Mohd Norzaidi Mat Nawi ◽  
Asrulnizam Abd Manaf ◽  
Mohd Rizal Arshad
Keyword(s):  

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

2000 ◽  
Author(s):  
Alex Povitsky

Abstract In this study we consider one method of parallelization of implicit numerical schemes on multiprocessor systems. Then, the parallel high-order compact numerical algorithm is applied to physics of amplification of sound waves in a non-uniform mean flow. Due to the pipelined nature of this algorithm, its efficient parallelization is based on scheduling of processors for other computational tasks while otherwise the processors stay idle. In turn, the proposed scheduling algorithm is taken as a special case of the general shop scheduling problem and possible extentions and generalizations of the proposed scheduling methodology are discussed. Numerical results are discussed in terms of baroclinic generation of wave-associated vorticity that appear to be a key process in energy transfer between a non-uniform mean flow and a propagating disturbance. The discovered phenomenon leads to significant amplification of sound waves and controls the direction of sound propagation.


Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 3674 ◽  
Author(s):  
Wei Lu ◽  
Yu Lan ◽  
Rongzhen Guo ◽  
Qicheng Zhang ◽  
Shichang Li ◽  
...  

A spiral sound wave transducer comprised of longitudinal vibrating elements has been proposed. This transducer was made from eight uniform radial distributed longitudinal vibrating elements, which could effectively generate low frequency underwater acoustic spiral waves. We discuss the production theory of spiral sound waves, which could be synthesized by two orthogonal acoustic dipoles with a phase difference of 90 degrees. The excitation voltage distribution of the transducer for emitting a spiral sound wave and the measurement method for the transducer is given. Three-dimensional finite element modeling (FEM)of the transducer was established for simulating the vibration modes and the acoustic characteristics of the transducers. Further, we fabricated a spiral sound wave transducer based on our design and simulations. It was found that the resonance frequency of the transducer was 10.8 kHz and that the transmitting voltage resonance was 140.5 dB. The underwater sound field measurements demonstrate that our designed transducer based on the longitudinal elements could successfully generate spiral sound waves.


Author(s):  
Zichen Wang ◽  
Jian Xu ◽  
Xuefeng Zhang ◽  
Can Lu ◽  
Kangkang Jin ◽  
...  

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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