Acoustic-Mean Flow Interactions.

Abstract

The objective of this research work was directed at gaining understanding of the physical mechanisms by which energy is exchanged between the mean and acoustic flow fields in resonant combustion chambers (in particular, solid rocket motors). These processes may alter the balance between sources and sinks of oscillatory energy in the combustor significantly and thus are critical to our ability to predict the stability characteristics of proposed motor designs. The present report is concentrated on the description and analysis of the computational results obtained to date in the study of acoustic refraction and flow turning phenomena. The time-dependent compressible Navier Stokes equations were solved utilizing an implicit, non-iterative Linearized Block Implicit scheme. In the first study acoustic wave propagation in a tube with a coexisting sheared mean flow was investigated. To help discriminate between acoustic energy loss due to artificial numerical dissipation and energy loss due to physical processes a second study was conducted in which acoustic wave propagation in a tube with no mean flow was investigated. The third study investigated acoustic wave propagation in a tube with a coexisting mean flow, where the mean flow is injected into the tube through its lateral boundary.

Document Details

Document Type
Technical Report
Publication Date
Jan 01, 1987
Accession Number
ADA176845

Entities

People

  • J. D. Baum
  • J. N. Levine

Organizations

  • Air Force Research Laboratory

Tags

Communities of Interest

  • Energy and Power Technologies
  • Weapons Technologies

DTIC Thesaurus Topics

  • Acoustic Refraction
  • Acoustic Waves
  • Chambers
  • Combustion
  • Combustion Chambers
  • Combustors
  • Equations
  • Flow
  • Flow Fields
  • Ignition
  • Navier Stokes Equations
  • Refraction
  • Rocket Engines
  • Wave Propagation
  • Waves

Fields of Study

  • Physics

Readers

  • Atmospheric Science / Meteorology, specifically Wind Wave Turbulence.
  • Combustion and Flow Dynamics.
  • Finite Element Method (FEM) for solving Partial Differential Equations (PDEs)