Acoustic scattering from an elastic prolate spheroid in a shallow‐water waveguide

1987 ◽  
Vol 82 (S1) ◽  
pp. S49-S49
Author(s):  
Gary S. Sammelmann ◽  
Roger H. Hackman
Keyword(s):  
Shallow Water ◽  
Acoustic Scattering ◽  
Prolate Spheroid

An overview of the 1995 SWARM shallow-water internal wave acoustic scattering experiment

1997 ◽  
Vol 22 (3) ◽  
pp. 465-500 ◽  
Author(s):  
J.R. Apel ◽  
M. Badiey ◽  
Ching-Sang Chiu ◽  
S. Finette ◽  
R. Headrick ◽  
...  
Keyword(s):  
Internal Wave ◽  
Shallow Water ◽  
Acoustic Scattering ◽  
Scattering Experiment

scholarly journals Estimation of the Coefficients of the Equation of Acoustic Target Strength Based on the Morphology of Coregonus migratorius (Georgi, 1775) Swim Bladder

2020 ◽  
Vol 15 (1) ◽  
pp. 89-98
Author(s):  
P. N. Anoshko ◽  
M. M. Makarov ◽  
S. B. Popov ◽  
A. I. Degtev ◽  
N. N. Denikina ◽  
...  
Keyword(s):  
Acoustic Scattering ◽  
Morphological Characteristics ◽  
Prolate Spheroid ◽  
The Body ◽  
Target Strength ◽  
Fish Length ◽  
Swim Bladder ◽  
Experimental Conditions ◽  
Scattering Model ◽  
Acoustic Target

Aim. The aim of the study was to estimate the coefficients of the equation TSmax=f(SL) considering the characteristics of an acoustic scattering model based on the morphological characteristics of the swim bladder of the Coregonus migratorius (Georgi, 1775). Material and Methods. Ninety‐nine living specimens of C. migratorius served as the study material. For each specimen, the target strength in the cage was measured using an Kongsberg Simrad EY500 echo sounder and the morphology of the swim bladder was studied. Measurements, analysis of images and data were conducted using Image Pro 6.0. Excel and SciLab software resources. Results. We determined the main morphological characteristics of the swim bladder in C. migratorius as well as the correspondence of its dimensions and proportions in relation to the length of the fish’s body. The coefficients of the equation TS=20log(SL)‐60, calculated on the results of the acoustic scattering model of a prolate spheroid, agree well with the coefficients calculated from maximum values obtained in the cage experiment. During the conversion of the coefficients relating to the allometric changes in the length of the swim bladder relative to fish length, the equation TS=23.2log(SL)‐64.4 was obtained. A comparative analysis of the available equations of the target strength for C. migratorius with those obtained in the study was undertaken. Conclusion. The equation obtained on the model of the swim bladder as a prolate spheroid adequately describes the dependence of the maximum values of the target strength on the body length of the C. migratorius and confirms the previously obtained dependence by maximum values of TS in the cage experimental conditions and can serve as a basis for further theoretical studies.

Acoustic scattering strength of turbulence generated waves in a shallow water flow

2011 ◽  
Vol 130 (4) ◽  
pp. 2436-2436
Author(s):  
V. Kirill Horoshenkov ◽  
Andrew Nichols ◽  
J. Simon Tait ◽  
A. German Maximov
Keyword(s):  
Shallow Water ◽  
Water Flow ◽  
Acoustic Scattering ◽  
Shallow Water Flow ◽  
Scattering Strength

Large-Amplitude Motion of an Elongated Body in Shallow Water

1980 ◽  
Vol 24 (04) ◽  
pp. 256-270
Author(s):  
Touvia Miloh ◽  
Aharon Hauptman
Keyword(s):  
Free Surface ◽  
Shallow Water ◽  
Large Amplitude ◽  
Equations Of Motion ◽  
Prolate Spheroid ◽  
The Body ◽  
Lagrange Equations ◽  
Bodies Of Revolution ◽  
Analytical Expressions ◽  
Large Amplitude Motion

A large-amplitude motion of a body of revolution in shallow water is analyzed by assuming the bottom to be even and the Froude number to be large enough for the velocity potential to vanish on the undisturbed free surface. First, the classical Kirchhoff-Lagrange equations of motion are extended to the case of time-dependent added-mass and inertia coefficients. The hydrodynamical force and moment acting on the body are expressed in terms of these coefficients together with their partial derivatives with respect to the generalized coordinates of the body. It is demonstrated how these expressions can be applied for the case of a prolate spheroid maneuvering in shallow water, where useful analytical expressions for the hydrodynamical coefficients are also obtained. By employing the concept of "equivalent spheroid" it is also shown that these results are universal in the sense that they may serve as useful approximations for arbitrary smooth bodies with axial symmetry. The hydrodynamical coefficients are given as a product of two terms, one which depends on the geometry of the body and the second on the relative position of the body with respect to the free surface. Both analytical and graphical solutions for these two functions are presented herein and it is also suggested how these can be used for a large-amplitude motion of nonspheroidal bodies of revolution.

Long-range acoustic scattering from a shallow-water mud-volcano cluster

2007 ◽  
Vol 122 (4) ◽  
pp. 1946-1958 ◽  
Author(s):  
Charles W. Holland ◽  
John R. Preston ◽  
Douglas A. Abraham
Keyword(s):  
Shallow Water ◽  
Long Range ◽  
Acoustic Scattering ◽  
Mud Volcano
Sign in / Sign up

Export Citation Format

Share Document