An analysis of low‐frequency wind‐generated ambient noise source levels in the ocean

1988 ◽  
Vol 83 (S1) ◽  
pp. S87-S87
Author(s):  
W. M. Carey ◽  
D. J. Kewley ◽  
D. G. Browning ◽  
W. A. Von Winkle
Keyword(s):  
Ambient Noise ◽  
Noise Source ◽  
Low Frequency

Wind‐generated, low‐frequency, ambient‐noise source levels revisited

1999 ◽  
Vol 106 (4) ◽  
pp. 2297-2297
Author(s):  
William M. Carey ◽  
David G. Browning
Keyword(s):  
Ambient Noise ◽  
Noise Source ◽  
Low Frequency

Low‐frequency wind‐generated ambient noise source levels

1990 ◽  
Vol 88 (4) ◽  
pp. 1894-1902 ◽  
Author(s):  
D. J. Kewley ◽  
D. G. Browning ◽  
W. M. Carey
Keyword(s):  
Ambient Noise ◽  
Noise Source ◽  
Low Frequency

scholarly journals Review of Research Results Concerning the Modelling of Shipping Noise

2021 ◽  
Vol 28 (2) ◽  
pp. 102-115
Author(s):  
Xiaowei Yan ◽  
Hao Song ◽  
Zilong Peng ◽  
Huimin Kong ◽  
Yipeng Cheng ◽  
...  
Keyword(s):  
Ambient Noise ◽  
Noise Source ◽  
Low Frequency ◽  
Empirical Models ◽  
Academic Community ◽  
Marine Ecology ◽  
Related Research ◽  
Research Results ◽  
Radiated Noise ◽  
Underwater Radiated Noise

Abstract The effect of underwater radiated noise (URN) pollution (produced by merchant ships) on marine ecology has become a topic of extreme concern for both the academic community and the general public. This paper summarises some research results and modelling about shipping noise published over several decades, which comprises the research significance of low-frequency ambient noise and shipping noise, shipping noise source levels (SL), empirical models and the measurement standards of shipping noise. In short, we try to present an overall outline of shipping noise and ocean ambient noise for related research.

A standard definition for wind‐generated, low‐frequency ambient noise source levels

1988 ◽  
Vol 84 (S1) ◽  
pp. S201-S201
Author(s):  
William M. Carey ◽  
William A. VonWinkle ◽  
David G. Browning ◽  
Douglas J. Kewley
Keyword(s):  
Ambient Noise ◽  
Noise Source ◽  
Low Frequency ◽  
Standard Definition

Noise source location and scaling of subsonic upper-surface blowing

2020 ◽  
Vol 19 (3-5) ◽  
pp. 191-206
Author(s):  
Trae L Jennette ◽  
Krish K Ahuja
Keyword(s):  
Strouhal Number ◽  
Noise Source ◽  
Low Frequency ◽  
Directivity Pattern ◽  
Source Location ◽  
Dipole Source ◽  
Frequency Noise ◽  
Noise Sources ◽  
Trailing Edge ◽  
Trailing Edge Noise

This paper deals with the topic of upper surface blowing noise. Using a model-scale rectangular nozzle of an aspect ratio of 10 and a sharp trailing edge, detailed noise contours were acquired with and without a subsonic jet blowing over a flat surface to determine the noise source location as a function of frequency. Additionally, velocity scaling of the upper surface blowing noise was carried out. It was found that the upper surface blowing increases the noise significantly. This is a result of both the trailing edge noise and turbulence downstream of the trailing edge, referred to as wake noise in the paper. It was found that low-frequency noise with a peak Strouhal number of 0.02 originates from the trailing edge whereas the high-frequency noise with the peak in the vicinity of Strouhal number of 0.2 originates near the nozzle exit. Low frequency (low Strouhal number) follows a velocity scaling corresponding to a dipole source where as the high Strouhal numbers as quadrupole sources. The culmination of these two effects is a cardioid-shaped directivity pattern. On the shielded side, the most dominant noise sources were at the trailing edge and in the near wake. The trailing edge mounting geometry also created anomalous acoustic diffraction indicating that not only is the geometry of the edge itself important, but also all geometry near the trailing edge.

scholarly journals Estimation of the Noise Source Level of a Commercial Ship Using On-Board Pressure Sensors

2021 ◽  
Vol 11 (3) ◽  
pp. 1243
Author(s):  
Hongseok Jeong ◽  
Jeung-Hoon Lee ◽  
Yong-Hyun Kim ◽  
Hanshin Seol
Keyword(s):  
Noise Source ◽  
Pressure Sensors ◽  
Low Frequency ◽  
Frequency Resolution ◽  
Source Strength ◽  
Recording Time ◽  
Source Level ◽  
The One ◽  
Hydrophone Array ◽  
Good Agreement

The dominant underwater noise source of a ship is known to be propeller cavitation. Recently, attempts have been made to quantify the source strength using on-board pressure sensors near the propeller, as this has advantages over conventional noise measurement. In this study, a beamforming method was used to estimate the source strength of a cavitating propeller. The method was validated against a model-scale measurement in a cavitation tunnel, which showed good agreement between the measured and estimated source levels. The method was also applied to a full-scale measurement, in which the source level was measured using an external hydrophone array. The estimated source level using the hull pressure sensors showed good agreement with the measured one above 400 Hz, which shows potential for noise monitoring using on-board sensors. A parametric study was carried out to check the practicality of the method. From the results, it was shown that a sufficient recording time is required to obtain a consistent level at high frequencies. Changing the frequency resolution had little effect on the result, as long as enough data were provided for the one-third octave band conversion. The number of sensors affected the mid- to low-frequency data.

Meteorological conditions influence on quantification of site effects at low frequency using the seismic ambient noise

2015 ◽  
Author(s):  
Rabah Bensalem* ◽  
Djamal Machane ◽  
Jean-Luc Chatelain ◽  
Mohamed Djeddi ◽  
Hakim Moulouel ◽  
...  
Keyword(s):  
Site Effects ◽  
Ambient Noise ◽  
Low Frequency ◽  
Meteorological Conditions ◽  
Seismic Ambient Noise
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