Underwater Acoustic Measurements and Their Applications

Björnö, L.

doi:10.1016/b978-0-12-811240-3.00014-x

Cited by 14 publications

(14 citation statements)

References 72 publications

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“…The basic equation for the sound propagation was given by Lighthill (1952) [1]. This equation was given .…”

Section: Mathematical Modelmentioning

confidence: 99%

“…In general, the left side of this equation is related to the sound propagation, and the right side is related to the sound sources. One of the analytic solutions presented for the Lighthill equation is the integral formula to solve it, which was presented by Fox Williams and Hawking (1969) [1]. In FVM software this equation is used for predicting the sound propagation by the propeller.…”

Section: Mathematical Modelmentioning

confidence: 99%

“…In recent years, several studies have been focused on understanding and reducing the noise generated by propulsion systems into oceans. Generally, we can divide the source of noise radiated by the marine vessel into four categories [1]:…”

Section: Introductionmentioning

confidence: 99%

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Hydrodynamic Analysis of Noise Propagation By the High Skew Marine Propeller Working in Non-Uniform Inflow

Hadipour

Abadi

Khanzadi

et al. 2021

International Journal of Applied Mechanics and Engineering

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Being able to predict ship and marine propulsion noise is an important issue for naval architectures and the international maritime community. The main objective of this paper is the numerical investigation on the noise propagation by the high skew marine propeller working in a non-uniform inflow via RANS solver in the broadband frequency range. The pressure fluctuations were monitored at three points on the propeller blade, then by using the FFT operator we computed the blade passing frequency (BPF) for different propeller loading conditions. Based on these pressure pulses and adopting the Fowcs Williams-Hawking model we calculated noise radiated at the monitoring points. The results showed the BPF and noise level increased by increasing the load on the blades and we also observed that the noise generated at the leading edge was greater than at other points. Furthermore, the study of pressure fluctuations showed the propeller tip has more pressure variations in one revolution than other regions of the propeller surface.

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“…The basic equation for the sound propagation was given by Lighthill (1952) [1]. This equation was given .…”

Section: Mathematical Modelmentioning

confidence: 99%

Section: Mathematical Modelmentioning

confidence: 99%

See 1 more Smart Citation

Hydrodynamic Analysis of Noise Propagation By the High Skew Marine Propeller Working in Non-Uniform Inflow

Hadipour

Abadi

Khanzadi

et al. 2021

International Journal of Applied Mechanics and Engineering

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“…Despite these successful applications, there are difficulties for heritage managers to use (linear) Chirp SBP systems for in situ management purposes, especially in shallow (<5 m water depths) owing to vessel-induced bubble turbulence, restricted acoustic geometry of the system, wide acoustic beam patterns and inability to discriminate in the top 30 cm. While Chirp systems can be pulled by divers to avoid boat noise interference (Plets et al 2007(Plets et al , 2009) and data processing techniques can be used to correct for geometry and optimize the processing of the collected data, their field operability remains difficult (Bjørnø 2017c). Chirp SBPs use wide acoustic beam patterns (20-30°) which limits horizontal resolution.…”

Section: Non-invasive Geophysical Measurementsmentioning

confidence: 99%

Quantifying Depth of Burial and Composition of Shallow Buried Archaeological Material: Integrated Sub-bottom Profiling and 3D Survey Approaches

Winton

2019

3D Recording and Interpretation for Maritime Archaeology

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This chapter presents proof of concept results from a program of in situ experimental and shipwreck survey measurements using non-linear (parametric) sub-bottom profiler (SBP) acoustic technology. Currently adopted acoustic methods have practical limitations for in situ management purposes for underwater sites with buried archaeological material. Sidescan and multibeam sensors do not quantify material buried below the seabed; linear SBP surveys are challenging to operate in very shallow water and have difficulties with respect to interpretation in the top 30 cm of the seabed; and confidence estimates for parametric SBP depth of burial measurements have yet to be published. The prime purposes of this research, consequently, are: to quantify shallow buried archaeological sites in 3D with confidence estimates, by measuring the depth of sediment cover, thickness and lateral extent of buried archaeological material; and to investigate relationships between acoustic waveform parameters and the type and degradation condition of that buried material. This improved measurement and interpretation capability, when combined with the other geophysical search tools such as multibeam echo sounders and magnetometers, will also aid in the assessment of the archaeological research potential of underwater sites.

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“…Typically, localization methods described in the literature are dependent to underwater sensor networks (UWASNs) and very varied both in terms of the number of transmitters and receivers used and their geometric configuration; see [4], [8]. Most of the listed technologies are individually interesting but they must be judiciously combined to give an easy-to-use system adapted to the application specifications.…”

Section: Introductionmentioning

confidence: 99%

Embedded acoustic long baseline localization system for autonomous underwater vehicles

Es-sadaoui

Khallaayoune

Brizard

2021

IJEECS

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<p>The attenuation of global positioning system (GPS) in water medium makes localization of autonomous uderwater vehicles (AUVs) particularly challenging. The long baseline (LBL) positioning system can extend GPS using beacons as references. This work aims at building an acoustic LBL-based system able to localize AUVs operating in swarms thanks to a small size acoustic transceiver embedded onboard AUVs and implementing range-based localization algorithms to estimate the swarm coordinates in real-time. The distances computation between navigating AUVs and fixed beacons were implemented in a digital signal processor (DSP) which computes the time-of-arrival (ToA) of incoming pure tone acoustic waves. The principle of design, hardware architecture, implementation, simulations and sea experiments are described in this paper. The experimental data showed an average deviation around 0.62 m when an AUV is placed at 45 m far away from a beacon. This deviation increases with distance: around 4.8 m measured at 500 m. This performance can be improved by taking into consideration the two main factors examined in this paper, which are sound velocity profile and propagation model.</p>

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Underwater Acoustic Measurements and Their Applications

Cited by 14 publications

References 72 publications

Hydrodynamic Analysis of Noise Propagation By the High Skew Marine Propeller Working in Non-Uniform Inflow

Hydrodynamic Analysis of Noise Propagation By the High Skew Marine Propeller Working in Non-Uniform Inflow

Quantifying Depth of Burial and Composition of Shallow Buried Archaeological Material: Integrated Sub-bottom Profiling and 3D Survey Approaches

Embedded acoustic long baseline localization system for autonomous underwater vehicles

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