Multidimensional Structure of Wall Bounded Turbulence-Continuation

Abstract

Broad goals of the work were to study the structure of the turbulent wall layer using modern particle image velocimetry techniques to measure instantaneous velocity fields and to interpret the structure. Earlier work (C. D. Meinhart, Ph.D. Thesis. Univ. Illinois, 1994) supported by ONR had suggested that low momentum regions are created in wall turbulence by the alignment of hairpin vortices, but the field of view of this work was not wide enough to see entire groups of vortices and the patterns in which they formed. Experiments were conducted in boundary layer using wide-angle PIV measurements that gave views of structure that had not been attainable before. They show that the hairpins definitely occur in packets that grow more or less linearly at an angle of 12 +/- 6 degrees with respect to the wall. Packets contain up to 12 hairpins were observed.

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Document Details

Document Type
Technical Report
Publication Date
Dec 22, 1998
Accession Number
ADA358703

Entities

People

  • Ronald J. Adrian

Organizations

  • University of Illinois Urbana–Champaign

Tags

Communities of Interest

  • Air Platforms
  • Materials and Manufacturing Processes

DTIC Thesaurus Topics

  • Boundary Layer
  • Boundary Layer Flow
  • Cameras
  • Computational Fluid Dynamics
  • Computational Science
  • Convection
  • Energy Transfer
  • Flow Visualization
  • Fluid Dynamics
  • Fluid Flow
  • Measurement
  • Mechanics
  • Photographs
  • Statistical Sampling
  • Three Dimensional
  • Turbulent Mixing
  • Two Dimensional

Fields of Study

  • Physics

Readers

  • Fluid Mechanics and Fluid Dynamics.
  • Human-Computer Interaction (HCI).
  • Technical Research and Report Writing.