A New Model of Resonant Acoustic Scattering by Swimbladder - Bearing Fish

Abstract

A new model of a swimbladder-bearing fish has been developed to provide improved predictions of the resonant frequency and acoustic cross section of such a fish. The model consists of a small spherical shell in water, enclosing an air cavity which supports a surface tension. The shell is a viscous, heat-conducting Newtonian fluid, with the physical properties of fish flesh. A comparison of the results obtained with the new model to experimental data indicates that the new model constitutes a definite improvement over previous models. The new model can predict the high values of damping and elevated resonant frequencies that previous models could not. The model appears to be most accurate for fish in which tension in the swimbladder wall has a minor effect on resonant scattering. This includes the fish which are of interest in studies of volume reverberation and therefore, the new model should be of considerable value in such studies.

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Document Details

Document Type
Technical Report
Publication Date
Aug 01, 1977
Accession Number
ADA049928

Entities

People

  • Richard H. Love

Organizations

  • United States Naval Research Laboratory

Tags

Communities of Interest

  • Air Platforms
  • Energy and Power Technologies
  • Materials and Manufacturing Processes

DTIC Thesaurus Topics

  • Acoustic Measurement
  • Acoustic Properties
  • Acoustic Waves
  • Acoustics
  • Animals
  • Cells
  • Equations
  • Experimental Data
  • Fish
  • Frequency
  • Heat Transfer
  • Measurement
  • Physical Properties
  • Resonant Frequency
  • Sea Water
  • Shear Modulus
  • Surface Tension

Readers

  • Aquatic Ecology
  • Computational Modeling and Simulation
  • Fluid Dynamics.