An Extension of Langer's Asymtotic Solution with Applications to Ocean Acoustics.

Abstract

In this dissertation, Langer's asymptotic solution for second order differential equations is applied to the problem of acoustical propagation in the ocean. Langer's solution is analogous to the WKB solution, but is developed in terms of the Airy functions. For illustrative c(z) functions (sound velocity vs. depth) typical of the deep ocean, the normal mode quantities of group velocity and mode cycle distance are computed using the formulae developed in this report. These are presented in the form of plots of, for example, group velocity versus phase velocity for frequencies in the range 10 Hz to 150 Hz. These plots illustrate the effects of the ocean surface and of anomalous segments of c(z) upon the mode quantities; the most prominent frequency dependent effects occur for modes whose phase velocities are close to the sound velocity at a boundary.

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Document Details

Document Type
Technical Report
Publication Date
Mar 01, 1977
Accession Number
ADA045346

Entities

People

  • Stephen K. Mitchell

Organizations

  • University of Texas at Austin

Tags

Communities of Interest

  • Advanced Electronics
  • Air Platforms
  • Counter IED
  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Acoustic Phenomena
  • Acoustic Propagation
  • Acoustic Properties
  • Acoustic Waves
  • Acoustics
  • Differential Equations
  • Equations
  • Explosives
  • Group Velocity
  • Oceanography
  • Oceans
  • Phase Velocity
  • Physics Laboratories
  • Plastic Explosives
  • Two Dimensional
  • Underwater Acoustics
  • Waveforms

Fields of Study

  • Mathematics

Readers

  • Control Systems Engineering.
  • Database Systems and Applications
  • Wave Propagation and Nonlinear Chaotic Dynamics.