Flow‐Noise Measurements in Water

1966 ◽  
Vol 40 (5) ◽  
pp. 1265-1265
Author(s):  
Gerald J. Franz
Keyword(s):  
Flow Noise ◽  
Noise Measurements

Conceptual Design of the Flow Noise Simulator

2003 ◽  
Author(s):  
Ryuichi Sato ◽  
Takayuki Mori ◽  
Ryo Yakushiji ◽  
Kenji Naganuma ◽  
Masaharu Nishimura ◽  
...  
Keyword(s):  
Conceptual Design ◽  
Large Scale ◽  
Scale Model ◽  
Variable Pressure ◽  
Cavitation Noise ◽  
Flow Noise ◽  
Model Studies ◽  
Surface Ship ◽  
Noise Measurements ◽  
Under Construction

The Flow Noise Simulator (FNS) of the 1st Research Center of TRDI/JDA (Japan Defense Agency) is a large, variable pressure, recirculating water tunnel with very low background noise level. The tunnel is 20m high and 49m long, containing 2000m3 of water. The test section has a square cross section of 2m × 2m with 10m in length. It will accept large size surface ship models of 6m, submarine models of 4m in length and full scale ship appendix models. The FNS is currently under construction and will be accomplished in 2005. It will be used for a wide variety of hydrodynamic and hydroacoustic testing of surface ships and submarines, such as propeller cavitation noise measurements and propeller-hull interaction observation, with sufficiently large scale models. Conceptual design of the FNS was started in 1996 and evaluated by following scale model studies. This paper discusses some technical issues of the FNS.

scholarly journals A Vector Sensor-Based Acoustic Characterization System for Marine Renewable Energy

2020 ◽  
Vol 8 (3) ◽  
pp. 187
Author(s):  
Kaustubha Raghukumar ◽  
Grace Chang ◽  
Frank Spada ◽  
Craig Jones
Keyword(s):  
Renewable Energy ◽  
Three Dimensional ◽  
Acoustic Flow ◽  
Flow Noise ◽  
Vector Sensor ◽  
Acoustic Signature ◽  
Vector Sensors ◽  
Noise Measurements ◽  
Noise Data ◽  
Using Data

NoiseSpotter is a passive acoustic monitoring system that characterizes, classifies, and geo-locates anthropogenic and natural sounds in near real time. It was developed with the primary goal of supporting the evaluation of potential acoustic effects of offshore renewable energy projects. The system consists of a compact array of three acoustic vector sensors, which measures acoustic pressure and the three-dimensional particle velocity vector associated with the propagation of an acoustic wave, thereby inherently providing bearing information to an underwater source of sound. By utilizing an array of three vector sensors, the application of beamforming techniques can provide sound source localization, allowing for characterization of the acoustic signature of specific underwater acoustic sources. Here, performance characteristics of the system are presented, using data from controlled acoustic transmissions in a quiet environment and ambient noise measurements in an energetic tidal channel in the presence of non-acoustic flow noise. Data quality is demonstrated by the ability to reduce non-acoustic flow noise contamination, while system utility is shown by the ability to characterize and localize sources of sound in the underwater environment.

Flow noise measurements at strong tidal current area in Uldolmok Waterway

2013 ◽  
Vol 133 (5) ◽  
pp. 3396-3396
Author(s):  
Myungkwon Ko ◽  
Jee Woong Choi
Keyword(s):  
Tidal Current ◽  
Flow Noise ◽  
Noise Measurements ◽  
Current Area ◽  
Strong Tidal Current

Flow noise reduction from superhydrophobic surfaces

Geophysics ◽  
2012 ◽  
Vol 77 (1) ◽  
pp. P1-P10 ◽  
Author(s):  
Thomas Elboth ◽  
Bjørn Anders Pettersson Reif ◽  
Øyvind Andreassen ◽  
Michael B. Martell
Keyword(s):  
Numerical Simulation ◽  
Hydrophobic Surface ◽  
Direct Numerical Simulations ◽  
Superhydrophobic Surfaces ◽  
Viscous Drag ◽  
Kinematic Structure ◽  
Simulation Data ◽  
Flow Noise ◽  
Noise Measurements ◽  
Highly Hydrophobic

This work investigates how a highly (super)hydrophobic surface can be used to reduce turbulence-generated drag and noise on a towed streamer cable. The work is done by analyzing full-scale drag and flow noise measurements taken on a commercial seismic streamer in combination with direct numerical simulations of turbulence-generated flow noise. The main findings are that viscous drag and flow noise can be significantly reduced on a seismic streamer that is coated to make the surface highly hydrophobic. In an ocean towing test, a 4% reduction of drag on a streamer section was measured. In a separate test on a commercial seismic vessel, a reduction in the flow noise level of nearly 50% (6 dB) for frequencies below 10 Hz was found. Based upon an analysis of numerical simulation data, it is suggested that the reduction in drag and noise can be attributed to a reduced level of shear stress and change in the kinematic structure of the turbulence, both of which occur in the immediate vicinity of the highly hydrophobic surface.

scholarly journals Flow noise measurements at strong tidal current area in Uldolmok Waterway

2013 ◽  
Author(s):  
Myungkwon Ko ◽  
Jee Woong Choi
Keyword(s):  
Tidal Current ◽  
Flow Noise ◽  
Noise Measurements ◽  
Current Area ◽  
Strong Tidal Current

scholarly journals Flow‐Noise Measurements with Buoyant Units

1959 ◽  
Vol 31 (11) ◽  
pp. 1567-1567
Author(s):  
G. P. Haddle ◽  
E. J. Skudrzyk
Keyword(s):  
Flow Noise ◽  
Noise Measurements

Infrasonic flow‐noise measurements using an H‐58 hydrophone

1976 ◽  
Vol 60 (S1) ◽  
pp. S19-S20
Author(s):  
O. M. Griffin ◽  
J. R. McGrath ◽  
R. A. Finger
Keyword(s):  
Flow Noise ◽  
Noise Measurements

scholarly journals Use of bispectral analysis in flow noise measurements

1991 ◽  
Vol 89 (4B) ◽  
pp. 2001-2001
Author(s):  
Mary F. Leibolt ◽  
Theordore M. Farabee
Keyword(s):  
Bispectral Analysis ◽  
Flow Noise ◽  
Noise Measurements

Infrasonic flow‐noise measurements using an H‐58 omnidirectional cylindrical hydrophone

1977 ◽  
Vol 61 (2) ◽  
pp. 390-396 ◽  
Author(s):  
James R. McGrath ◽  
Owen M. Griffin ◽  
Robert A. Finger
Keyword(s):  
Flow Noise ◽  
Noise Measurements
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