RESONANT THERMAL-ACOUSTIC OSCILLATIONS.

Abstract

Small amplitude resonant motions of an inviscid, polytropic gas, contained in a tube of finite length, are investigated. It is postulated that motion of the gas may be represented as the super-position of two small amplitude simple waves which interact only at the boundaries. As a result, the problem reduces to solving a nonlinear difference equation, and this is effected on the basis that the solution is in the neighborhood of a linear standing wave. A consequence is that waves progress as acoustic waves, but the signal carried is determined by a nonlinear equation. The problems considered are the determination of the motion of the gas which is being forced at a resonant frequency at one end of a tube, while the other end may be open or closed. Self-sustained oscillations for these cases are also treated. For these resonant motions, the amplitude of the motion at particles away from the ends is greater than that of the driving mechanism. When the end of the tube is closed, shocks are a feature of the solution. For an open end, the motion is continuous. (Author)

Document Details

Document Type
Technical Report
Publication Date
Oct 01, 1969
Accession Number
AD0699804

Entities

People

  • Michael P. Mortell

Organizations

  • Lehigh University

Tags

DTIC Thesaurus Topics

  • Acoustic Waves
  • Amplitude
  • Boundaries
  • Difference Equations
  • Doppler Effect
  • Equations
  • Frequency
  • Frequency Shift
  • Mathematical Analysis
  • Mathematics
  • Oscillation
  • Resonant Frequency
  • Standing Waves
  • Waves

Fields of Study

  • Physics

Readers

  • Atmospheric Science / Meteorology, specifically Wind Wave Turbulence.
  • Fluid Dynamics.