On the Spreading Rate and Structure of a Turbulent Spot.

Abstract

Velocity measurements in the plane of symmetry of a turbulent spot are reported. The number of data points taken at various streamwise locations was adequate to map the ensemble-averaged flow field in a spot at a given instance. These results are compared to velocity taken in laboratory coordinates (i.e., at a given station with variable time), whereupon it is shown that the flow field in the spot depends either on its distance from its origin or on the time elapsed from its initiation. The two variables are not independent, so the flow may be transformed into a time (space) independent problem. The dependence of the spot on the Reynolds number and on the surrounding laminar boundary layer is established. The effects of these parameters on the shape of the ensemble-averaged spot, its size, characteristic celerities, and relative rate of entrainment, are discussed. (Author)

Open PDF

Document Details

Document Type
Technical Report
Publication Date
Mar 19, 1980
Accession Number
ADA086445

Entities

People

  • I. Wygnanski
  • J. Haritonidis

Organizations

  • Tel Aviv University

Tags

Communities of Interest

  • Air Platforms
  • Energy and Power Technologies
  • Materials and Manufacturing Processes

DTIC Thesaurus Topics

  • Air Force
  • Boundaries
  • Boundary Layer
  • Data Acquisition
  • Entrainment
  • Flow
  • Flow Fields
  • Flow Visualization
  • Fluid Mechanics
  • Free Stream
  • Laminar Boundary Layer
  • Layers
  • Leading Edges
  • Measurement
  • Reynolds Number
  • Symmetry
  • Turbulent Boundary Layer

Fields of Study

  • Physics

Readers

  • Atmospheric Science / Meteorology, specifically Wind Wave Turbulence.
  • Fluid Mechanics and Fluid Dynamics.
  • Regression Analysis.

Technology Areas

  • Space
  • Space - Hall-Effect Thruster