Propagation of Sound through a Gas with an Over-Population of Excited Vibrational States.

Abstract

Calculations have been made which predict sound amplification under certain conditions when propagated through a gas with an overpopulation of vibrationally excited states. Three metastable states have been analyzed where the vibrational temperature is varying slowly on the scale of the sound period. The first is that of a long-lived vibrational mode in a diatomic gas. Calculations were made for N2, CO, 02, and C12. The second is that of a fast v-v exchange followed by a slow v-t. Calculations were made for CD4 as an example of this situation. And the third is that of a slow v-v followed by a fast v-t. Calculations were made for a mixture of N2/C02/He as an example of this situation. Some of the difficulties in experimentally observing the gain are discussed. (Author)

Open PDF

Document Details

Document Type
Technical Report
Publication Date
Oct 20, 1983
Accession Number
ADA134181

Entities

People

  • F. Douglas Shields

Organizations

  • University of Mississippi

Tags

Communities of Interest

  • Energy and Power Technologies
  • Materials and Manufacturing Processes

DTIC Thesaurus Topics

  • Acoustic Propagation
  • Collisions
  • Energy
  • Energy Transfer
  • Equations
  • Frequency
  • Metastable State
  • Military Research
  • Mississippi
  • Molecules
  • Physics
  • Relaxation Time
  • Sound Waves
  • Specific Heat
  • United States
  • Universities
  • Waves

Fields of Study

  • Physics

Readers

  • Molecular Photonics/Laser Physics
  • Wave Propagation and Nonlinear Chaotic Dynamics.