Interaction of a Three-Dimensional Roughness Element with a Laminar Boundary Layer

Abstract

An experimental investigation is described that is directed toward extending the technical database and furthering our understanding of boundary layer transition induced by three-dimensional roughness elements. The investigation was carried out in an unsteady wind tunnel, principally with hemispherical roughness elements, in a well characterized zero-pressure gradient laminar boundary layer on a flat plate. Attention was directed toward the following aspects of the behavior of a three dimensional roughness element: (1) the critical Reynolds number of transition and the effect of aspect ratio thereon, (2) eddy generation is steady and unsteady flows, (3) is the fundamental process stability governed, and (4) the evolutionary change in mean velocity and intensity of the velocity fluctuation associated with the transition to fully developed turbulent flow.

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Document Details

Document Type
Technical Report
Publication Date
Mar 01, 1987
Accession Number
ADA178668

Entities

People

  • K. D. Tidstron
  • P. S. Klebanoff
  • W. G. Cleveland Jr.

Organizations

  • Arnold Engineering Development Complex

Tags

Communities of Interest

  • Energy and Power Technologies
  • Materials and Manufacturing Processes

DTIC Thesaurus Topics

  • Air Force
  • Aspect Ratio
  • Boundary Layer
  • Boundary Layer Transition
  • Databases
  • Flow Visualization
  • Fluid Dynamics
  • Laminar Boundary Layer
  • Measurement
  • Pressure Gradients
  • Reynolds Number
  • Steady Flow
  • Three Dimensional
  • Turbulent Flow
  • Turbulent Mixing
  • Unsteady Flow
  • Wind Tunnels

Fields of Study

  • Physics

Readers

  • Fluid Dynamics.
  • Systems Analysis and Design