A General Introduction to Aeroacoustics and Atmospheric Sound

Abstract

This paper uses a single unifying principle (based upon the nonlinear momentum-flux effects produced when different components of a motion transport different components of its momentum) to give a broad scientific background to several aspects of the interaction between airflows and atmospheric sound. First, it treats the generation of sound by airflows of many different types. These include, for example, jet-like flows involving convected turbulent motions -- with the resulting aeroacoustic radiation sensitively dependent on the Mach number of convection -and they include, as an extreme case, the supersonic boom (shock waves generated by a supersonically convected flow pattern). Next, the paper analyses sound propagation through nonuniformly moving airflows, and quantifies the exchange of energy between flow and sound; while, finally, it turns to problems of how sound waves on their own may generate the airflows known as acoustic streaming. aeroacoustics; turbulence; sonic boom.

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Document Details

Document Type
Technical Report
Publication Date
Oct 01, 1992
Accession Number
ADA257887

Entities

People

  • James Lighthill

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Acoustic Propagation
  • Acoustic Waves
  • Acoustics
  • Boundary Layer
  • Computational Fluid Dynamics
  • Convection
  • Doppler Effect
  • Energy Transfer
  • Fluid Dynamics
  • Fluid Mechanics
  • Mach Number
  • Shock Waves
  • Sound Waves
  • Standing Waves
  • Turbulent Mixing
  • Waveforms
  • Waves

Fields of Study

  • Physics

Readers

  • Fluid Mechanics and Fluid Dynamics.
  • Wave Propagation and Nonlinear Chaotic Dynamics.

Technology Areas

  • Hypersonics
  • Hypersonics - Hypersonic Flight
  • Hypersonics - Hypersonic Flow