Effects of Streamwise Pressure Gradients on Turbulence Structure in the Viscous Layer

Abstract

In order to provide bases for hydroacoustic models predicting wall pressure fluctuations in turbulent boundary layers, time series measurements with an X-probe and a wall shear stress sensor were obtained simultaneously in an oil channel both for fully-developed and for laterally-converging flows. Data were concentrated in the viscous layer at y = 5, 7, 10, 15, 25 and centerplane for K sub p = (nu/rho u-cubed)dp/dx = -0.008 to -0.02 (slight to highly favorable pressure gradients). Results presented include comparisons of the profiles of the mean statistics, plus correlations, of u, v, uv and t sub w. The mean profile u (y) increased and the correlation coefficients Ruu (y approx 15, tau*), Ruv (15 tau*) and R sub(u tau) (15, tau*) broadened with an increase in the magnitude of K sub p over this range. However, the turbulence statistics u'(y)/ut, v'(y)/u, S sub u (y) and F sub u (y) as well as the maximum amplitudes of R sub uv (15, tau) and R sub u tau (15, tau) suffered no significant effect. Keywords: Hydrodynamics, Hydroacoustics, Fluid mechanics, Turbulence structure, Hot film anemometry, Viscous wall layer.

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Document Details

Document Type
Technical Report
Publication Date
Jul 13, 1990
Accession Number
ADA225048

Entities

People

  • Donald M. Mceligot
  • Helmut Eckelmann

Tags

Communities of Interest

  • Sensors
  • Weapons Technologies

DTIC Thesaurus Topics

  • Boundary Layer
  • Computational Fluid Dynamics
  • Flow Visualization
  • Fluid Dynamics
  • Fluid Mechanics
  • Hydrodynamics
  • Measurement
  • Mechanical Engineering
  • Mechanical Properties
  • Mechanics
  • Physics Laboratories
  • Pressure Gradients
  • Shear Stresses
  • Statistics
  • Turbulence
  • Turbulent Boundary Layer
  • Turbulent Mixing

Fields of Study

  • Physics

Readers

  • Analytical Mechanics
  • Fluid Mechanics and Fluid Dynamics.