A Revision of Coupled Mode Theory for Irregular Acoustic Waveguides

Abstract

This note concerns new eigenfunction expansions for the fields in an irregular acoustic waveguide. The expansions are associated with a non- selfadjoint eigenvalue problem that has the eigenvalue in some of the boundary conditions. The waveguide consists of two layers of fluid that are separated by a frictionless free interface. The field expansions converge uniformly on both sides of the interface even if the fluid density as discontinuous at the interface. We use the eignefunction expansions to convert the reduced wave equation and the conditions at the boundaries of the waveguide into a system of first-order, ordinary differential equations. These coupling equations are similar to Shevchenko's equations for coupling between local modes in the waveguide (Sov. Phys. Acoust. 7 (1962) pp. 392-397, eqs. (16-18)).

Open PDF

Document Details

Document Type
Technical Report
Publication Date
Aug 08, 1988
Accession Number
ADA198466

Entities

People

  • Rondald F. Pannatoni

Tags

DTIC Thesaurus Topics

  • Acoustic Fields
  • Acoustic Waveguides
  • Acoustics
  • Boundaries
  • Couplings
  • Differential Equations
  • Eigenvalues
  • Eigenvectors
  • Equations
  • Geometry
  • North Carolina
  • Partial Differential Equations
  • Real Variables
  • Security
  • Wave Equations
  • Waveguides

Fields of Study

  • Physics

Readers

  • Calculus or Mathematical Analysis
  • Fluid Dynamics.
  • Microwave Engineering.