The Turbulent Wall Jet

Abstract

The flow of a wall jet embedded in an external stream or in a quiescent surrounding fluid was investigated experimentally. It was determined that the flow scales with the excess momentum injected into the stream and the viscosity of the fluid rather than the jet efflux velocity and the dimension of the nozzle. In the presence of an external stream, a velocity ratio parameter R = (U i - U.)/(Uj + U ) had to be added in order to obtain a universal scaling of this flow. Low-amplitude external excitation, of the wall jet resulted in a reduction of skin friction and therefore a reduction of drag. The only possible cause for this behavior observed is the enhancement of the two-dimensionality of the large eddies as expressed by spanwise coherence and correlation measurements.... Turbulence, Control of Shear Flows, Wall Jet, Boundary Layer Control

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Document Details

Document Type
Technical Report
Publication Date
May 18, 1993
Accession Number
ADA267675

Entities

People

  • I. Wygnanski
  • M. D. Zhou

Organizations

  • University of Arizona

Tags

Communities of Interest

  • Air Platforms
  • Space

DTIC Thesaurus Topics

  • Amplitude
  • Boundary Layer
  • Boundary Layer Control
  • Computational Fluid Dynamics
  • Drag
  • Flow Visualization
  • Fluid Dynamics
  • Fluid Mechanics
  • Friction
  • Mechanical Engineering
  • Mechanical Properties
  • Mechanics
  • Momentum
  • Reynolds Number
  • Shear Flow
  • Skin Friction
  • Viscosity

Fields of Study

  • Physics

Readers

  • Combustion and Flow Dynamics.
  • Fluid Mechanics and Fluid Dynamics.