Underwater radiated noise reduction technology using sawtooth duct for pumpjet propulsor

Qin, Denghui; Pan, Guang; Lee, Seongkyu; Huang, Qiaogao; Shi, Yue

doi:10.1016/j.oceaneng.2019.106228

Cited by 52 publications

(14 citation statements)

References 18 publications

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“…This hybrid CFD method, which was originally developed for aeroacoustic calculations, has been one of the most widely used approaches in the field of underwater noise prediction [35]- [38]. The sound pressure level results simulated by the hybrid CFD numerical approach agree well with the experimental results [32] for the noise data of a propeller. Our solution to predict the flow noise is accomplished in three steps.…”

Section: B Cfd-based Flow Noise Analysismentioning

confidence: 62%

“…To select an appropriate mesh size for CFD simulations, a grid independence study is necessary. The gridconvergence index (GCI) based on the theory of Richardson extrapolation [30] has been used to validate the grid independence [31], [32]. Through multiple sets of grid independence tests, the mesh size is set to 6 × 10 6 for our subsequent analyses.…”

Section: B Cfd-based Flow Noise Analysismentioning

confidence: 99%

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Self-Noise Spectrum Analysis and Joint Noise Filtering for the Sea-Wing Underwater Glider Based on Experimental Data

et al. 2020

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Using underwater gliders to measure underwater acoustic signals is a new measurement method emerging with the development of platform technology. Although underwater gliders are relatively quiet due to the absence of propellers, vehicle noise generated during motion is still inevitable, which will affect the recorded acoustic data. In this paper, we analyze the self-noise characteristics of underwater gliders based on simulated data by CFD technology for the hydrodynamic flow noise and experimental data acquired in an anechoic-water-tank experiment for the mechanical noise. The mechanical noise covers noises generated by buoyancy regulating (increasing and reducing), pitch regulating, rudder regulating and CTD pump working. According to the analysis results, the flow noise and CTD pump working noise could be ignored for the experimental data processing of sea trials. An experiment was conducted with an acoustic Sea-Wing underwater glider in the South China Sea from July 31 to September 4, 2018. Two kinds of noisy data were recorded, including target signals and ambient noise. All the target signals could be recognized after convolution filtering, except during the buoyancy regulating periods due to the high noise spectrum level. For the recorded ambient noise, in addition to the buoyancy regulating noise, the rudder and pitch regulating noises affected the recorded data. Then based on the acquired knowledge, a joint convolution filtering and thresholding method is proposed to remove the rudder and pitch noises from recorded noisy data. Kernels extracted from data acquired in the anechoic-water-tank experiment are used in the convolution filtering to localize each regulating action and energy thresholding is adopted to determine the duration of each regulation. All the rudder and pitch noises are removed from the recorded noisy data. INDEX TERMS Underwater glider, noise filtering, self-noise characteristics, hydrodynamic flow noise, mechanical noise, experimental data processing.

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Section: B Cfd-based Flow Noise Analysismentioning

confidence: 62%

Section: B Cfd-based Flow Noise Analysismentioning

confidence: 99%

Self-Noise Spectrum Analysis and Joint Noise Filtering for the Sea-Wing Underwater Glider Based on Experimental Data

et al. 2020

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“…To effectively protect urban areas from acoustic pollution, acoustic screens are used that are installed in the path of sound wave propagation. Most often they are a structure containing a foundation base, a basement, a bearing base, transverse struts, longitudinal profiles and sound-reflecting or sound-absorbing panels, in some cases it is proposed to use both types of panels [13][14][15][16]. As a result of the interaction of "И-II" and the acoustic field "A-II.1", two sound fields are formed:…”

Section: Resultsmentioning

confidence: 99%

Building a physical model of acoustic air pollution reduction process for brick manufacturing enterprises

2020

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The article is devoted to the study of the air acoustic pollution reduction process for brick manufacturing enterprises based on the physical and energy approach based on the theory of dispersed systems. The authors performed physical modeling of the process taking into account the properties of all the objects taking part in it at each stage and the features of the space in which it is implemented. Based on the constructed model, a mathematical description of the probability of the process and its effectiveness is obtained.

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Section: Introductionmentioning

confidence: 99%

“…The hybrid method has also contributed to developing noise reduction solutions for marine propellers, particularly for ducted propellers [2,8,9]. Qin et al [8] and Sun et al [9] used detached eddy simulation (DES) and the FW-H analogy to predict the noise reduction capability of the pumpjet propulsors with trailing edge serrations on decelerating ducts, which has demonstrated noise reduction but with a compromised hydrodynamic performance. It is found that the noise reduction is due to the disruption of the coherent vortex structure in the propeller slipstream, breaking down big vortex structures into smaller ones which can then be quickly attenuated to heat.…”

Section: Introductionmentioning

confidence: 99%

Hydroacoustic and hydrodynamic investigation of bio-inspired leading-edge tubercles on marine-ducted thrusters

Stark

Shi

2021

R. Soc. open sci.

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Underwater radiated noise (URN) has a negative impact on the marine acoustic environment where it can disrupt marine creature's basic living functions such as navigation and communication. To control the ambient ocean noise levels due to human activities, international governing bodies such as the International Maritime Organization (IMO) have issued non-mandatory guidelines to address this issue. Under such framework, the hydroacoustic performance of marine vehicles has become a critical factor to be evaluated and controlled throughout the vehicles' service life in order to mitigate the URN level and the role humankind plays in the ocean. This study aims to apply leading-edge (LE) tubercles of the humpback whales’ pectoral fins to a benchmark ducted propeller to investigate its potential in noise mitigation. This was conducted using CFD, where the high-fidelity improved delayed detached eddy simulations (IDDES) in combination with the porous Ffowcs-Williams Hawkings (FW-H) acoustic analogy was used to solve the hydrodynamic flow field and propagate the generated noise to the far-field. It has been found that the LE tubercles have shown promising noise mitigation capabilities in the far-field, where the OASPL at J = 0.1 was reduced to a maximum of 3.4 dB with a maximum of 11 dB reduction in certain frequency ranges at other operating conditions. Based on detailed flow analysis researching the fundamental vortex dynamics, this noise reduction is shown to be due to the disruption of the coherent turbulent wake structure in the propeller slipstream causing the acceleration in the dissipation of turbulence and vorticity-induced noise.

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Underwater radiated noise reduction technology using sawtooth duct for pumpjet propulsor

Cited by 52 publications

References 18 publications

Self-Noise Spectrum Analysis and Joint Noise Filtering for the Sea-Wing Underwater Glider Based on Experimental Data

Self-Noise Spectrum Analysis and Joint Noise Filtering for the Sea-Wing Underwater Glider Based on Experimental Data

Building a physical model of acoustic air pollution reduction process for brick manufacturing enterprises

Hydroacoustic and hydrodynamic investigation of bio-inspired leading-edge tubercles on marine-ducted thrusters

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