THE TWO DIMENSIONAL MIXING REGION,

Abstract

The two-dimensional incompressible mixing layer was investigated by using constant temperature, linearized hot wire anemometers. The measurements were divided into three categories: (1) the conventional average measurements, (2) time-average measurements in the turbulent and the non-turbulent zones, and (3) ensemble average measurements conditioned to a specific location of the interface. The turbulent energy balance was constructed twice, once using the conventional results and again using the turbulent zone results. Some differences transpired between the two sets of results. It appears that the mixing region can be divided into two regions, one on the high velocity side which resembles the outer part of a wake and the other on the low velocity side which resembles a jet. The binding turbulent-non-turbulent interfaces seem to move independently of each other. There is a strong connection between the instantaneous location of the interface and the axial velocity profile. Indeed the well known exponential mean velocity profile never actually exists at any given instant. In spite of the complexity of the flow the simple concepts of eddy viscosity and eddy diffusivity appear to be valid within the turbulent zone. (Author)

Document Details

Document Type
Technical Report
Publication Date
Feb 01, 1970
Accession Number
AD0703185

Entities

People

  • H. E. Fiedler
  • I. Wygnanski

Organizations

  • Boeing

Tags

DTIC Thesaurus Topics

  • Anemometers
  • Atmospheric Motion
  • Biological Phenomena
  • Diffusivity
  • Ecological And Environmental Phenomena
  • Ecological And Environmental Processes
  • Hot Wire
  • Hot Wire Anemometers
  • Measurement
  • Measuring Instruments
  • Meteorological Phenomena
  • Motion
  • Physical Properties
  • Two Dimensional
  • Viscosity
  • Wind

Readers

  • Fluid Dynamics.
  • Fluid Mechanics and Fluid Dynamics.