Numerical Study of Wave Propagation in a Non-Uniform Flow

Abstract

The propagation of acoustic waves originating from cylindrical and spherical pulses, in a non-uniform mean flow, and in the presence of a reflecting wall is investigated by Hardin and Pope approach using compact approximation of spatial derivatives. The 2-D and 3-D stagnation flows and a flow around a cylinder are taken as prototypes of real world flows with strong gradients of mean pressure and velocity. The intensity and directivity of acoustic wave patterns appear to be quite different from the benchmark solutions obtained in a static environment for the same geometry. The physical reasons for amplification and weakening of sound are discussed in terms of dynamics of wave profile and redistribution of acoustic energy and its potential and kinetic components. For an acoustic wave in the flow around a cylinder, the observed mean acoustic pressure is approximately doubled (upstream pulse position) and halved (downstream pulse position) in comparison with the sound propagation in static ambient conditions.

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Document Details

Document Type
Technical Report
Publication Date
Sep 01, 2000
Accession Number
ADA383719

Entities

People

  • Alex Povitsky

Tags

DTIC Thesaurus Topics

  • Acoustic Propagation
  • Acoustic Waves
  • Computational Fluid Dynamics
  • Equations
  • Flow
  • Geometry
  • Inviscid Flow
  • Mach Number
  • Potential Energy
  • Potential Flow
  • Pressure Distribution
  • Pressure Gradients
  • Simulations
  • Sound Waves
  • Three Dimensional
  • Two Dimensional
  • Wave Propagation

Fields of Study

  • Physics

Readers

  • Atmospheric Science / Meteorology, specifically Wind Wave Turbulence.
  • Electromagnetic Wave Scattering and Antenna Radiation Engineering
  • Fluid Dynamics.