Attenuation of Low Order Modes in Lossy Acoustic Wave Guides.

Abstract

Acoustic propagation is treated for sound sources in an ocean bounded from below by stratified layering. The bounding layers of the waveguide may be homogeneous-isovelocity or inhomogeneous with vertical sound speed gradients. The layers may be dissipative or nondissipative. The acoustic field is described with a normal mode expansion and modal attenuation coefficients are calculated for low order modes as a function of mode number and either frequency or phase velocity. The theoretical basis of the calculations is presented for multilayer isovelocity guides and for multilayer guides with index or refraction squared varying linearly with depth. Numerical results are presented for the Pekeris model of a fluid layer over a dissipative fluid halfspace. A comparison is made between various attenuation coefficients proposed in the literature. (Author)

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Document Details

Document Type
Technical Report
Publication Date
Dec 01, 1979
Accession Number
ADA079562

Entities

People

  • Harold David Leslie

Organizations

  • Woods Hole Oceanographic Institution

Tags

Communities of Interest

  • Air Platforms
  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Acoustic Propagation
  • Acoustic Waves
  • Acoustics
  • Bessel Functions
  • Computational Science
  • Computer Programs
  • Equations
  • Grain Size
  • Grazing Angles
  • Phase Velocity
  • Refraction
  • Refractive Index
  • Standing Waves
  • Wave Equations
  • Wave Functions
  • Wave Propagation
  • Waveforms

Fields of Study

  • Physics

Readers

  • Acoustical Oceanography.
  • Fluid Dynamics.
  • Wave Propagation and Nonlinear Chaotic Dynamics.