ANALYSIS OF FAR-FIELD MIXING WITH A PERIODIC SOURCE OF VORTICITY AT THE ORIFICE,

Abstract

Mechanical vibration of an orifice produces a periodic source of vorticity. In the part of the jet beyond the potential core (far-field) the vibration driven vortices concentrate in the outer regions. These are large eddies in comparison with the normal turbulent eddies. It is demonstrated that under such conditions there are two fairly distinct regions in the far-field. An inner turbulent, and an outer (vibration driven) large eddy, region. The large scale velocity fluctuations in the outer region are derived analytically. A numerical analysis determines the mean velocity profile over the whole jet. As the outer region vortices influence the characteristics of the turbulent inner region to some extent (angle of spread of jet and rate of change of axial velocity with distance), boundary conditions for the numerical analysis are best established by experimental measurement. (Author)

Document Details

Document Type
Technical Report
Publication Date
Feb 01, 1968
Accession Number
AD0828529

Entities

People

  • P. D. Mccormack

Tags

DTIC Thesaurus Topics

  • Boundaries
  • Far Field
  • Measurement
  • Motion
  • Numerical Analysis
  • Vibration

Fields of Study

  • Physics

Readers

  • Atmospheric Science / Meteorology, specifically Wind Wave Turbulence.
  • Combustion and Flow Dynamics.
  • Structural Dynamics.