Transient Acoustic Wave Propagation in Stratified Fluids.

Abstract

Transient acoustic wave propagation is analyzed for the case of plane-stratified fluids having density rho(y) and sound speed c(y) at depth y. For infinite fluids it is assumed that the (in general discontinuous) functions rho(y), c(y) are uniformly positive and bounded and satisfy abs.val (rho(y) - rho(at infinity)) < or = C(+ or - y) to the - alpha power, abs. val. (c(y) - c(at infinity)) < or = C(+ or - y) to the - alpha power for + or - y > 0, where alpha > 3/2. Semi-infinite and finite layers are also treated. The acoustic potential is a solution of the wave equation del-squared u/del t-squared - c-squared(y) rho(y) del dot (1/rho(y)grad(u)) = f(t,x,y) where x = (x1,x2) are horizontal coordinates and f(t,x,y) characterizes the wave sources. The principal results of the analysis show that u is the sum of a free component, which behaves like a diverging spherical wave for large t, and a guided component which is approximately localized in regions abs. val. (y - y sub j) < h sub j where c(y) has minima and propagates outward in horizontal planes like a diverging cylindrical wave. (Author)

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Document Details

Document Type
Technical Report
Publication Date
Jul 01, 1981
Accession Number
ADA104187

Entities

People

  • Calvin H. Wilcox

Organizations

  • University of Utah

Tags

Communities of Interest

  • Air Platforms
  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Acoustic Fields
  • Acoustic Waves
  • Cartesian Coordinates
  • Dispersion Relations
  • Energy
  • Equations
  • Integral Equations
  • Integrals
  • Layers
  • Military Research
  • Stationary
  • Stratified Fluids
  • United States Government
  • Wave Equations
  • Wave Functions
  • Wave Propagation
  • Waves

Readers

  • Analytical Mechanics
  • Atmospheric Science / Meteorology, specifically Wind Wave Turbulence.