SOUND PROPAGATION IN RAREFIED GASES

Abstract

A study of sound propagation in rarefied gases is described with particular emphasis on the propagation in the geometrical relaxation regime where the sound carrying molecules do not suffer intermolecular collisions during the flight from the transmitter to the receiver. The propagation is characterized by the attenuation and the phase parameters. The dependence of these dispersion parameters on the separation between the transducers, the velocity distribution of the molecules sub sequent to their interaction with the transmitter surface and the boundary conditions describing molecular-surface interactions is ascertained in terms of a semiphenomenological theory. Experiments for measuring the dispersion parameters are described and the results are discussed and compared with theory. A theory and an experiment for determining surface accommodation coefficients using sound propagation in rarefied gas are outlined. Finally a theoretical model is constructed that leads to a reasonable qualitative and quantitative description of sound propagation in rarefied gases.

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Document Details

Document Type
Technical Report
Publication Date
Nov 01, 1964
Accession Number
AD0608626

Entities

Organizations

  • BBN Technologies

Tags

Communities of Interest

  • Air Platforms
  • Engineered Resilient Systems
  • Space
  • Weapons Technologies

DTIC Thesaurus Topics

  • Acoustic Propagation
  • Aeronautical Engineering
  • Air Force Facilities
  • Boltzmann Equation
  • Collisions
  • Dispersions
  • Engineering
  • Equations
  • Fluid Dynamics
  • Free Flight
  • Gas Dynamics
  • Jet Propulsion
  • Measurement
  • Mechanical Engineering
  • Physics Laboratories
  • Rarefied Gases
  • Standing Waves

Fields of Study

  • Physics

Readers

  • Acoustics.
  • Fluid Dynamics.
  • Theoretical Analysis.