Velocity Measurements for Turbulent Nonseparated Flow over Solid Waves

Abstract

Laser-Doppler velocimetry measurements have been made of nonseparated velocity fields over solid sinusoidal wavy surfaces. Time-averaged velocity and turbulent intensity data are given. The measurements were conducted over waves on the bottom wall of a rectangular channel with a cross section of twenty four by two inches, the two inch dimension being vertical. Two sets of velocity data were obtained at conditions corresponding to flows where linear and nonlinear shear stress responses are observed. The conditions were wave steepnesses 2a lambda, and channel Reynolds numbers of 0.03125, 6400, and 0.05, 38,800 respectively. The wavelength of the waves was two inches. The viscous wall region was of particular interest. Sufficient measurements were taken to give an accurate representation of both the streamwise and normal variation of the viscous wall region. The data was Fourier analyzed to determine the extent of nonlinearities, the wavelength average flowfields, and the amplitudes and phases of the velocity responses. The physical meaning of the data is interpreted in terms of pressure gradient effects along the wave surfaces. Comparisons of the data with prediction from simple eddy viscosity models are also given. Keywords; Turbulent flow; waves; and Computer programs. (Thesis)

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Document Details

Document Type
Technical Report
Publication Date
Dec 18, 1985
Accession Number
ADA168682

Entities

People

  • Kenneth A. Frederick
  • Thomas J. Hanratty

Organizations

  • University of Illinois Urbana–Champaign

Tags

Communities of Interest

  • Weapons Technologies

DTIC Thesaurus Topics

  • Boundary Layer
  • Chemical Engineering
  • Computational Fluid Dynamics
  • Computational Science
  • Coordinate Systems
  • Fluid Dynamics
  • Fourier Analysis
  • Measurement
  • Mechanical Engineering
  • Naval Architecture
  • Pressure Gradients
  • Pressure Measurement
  • Reynolds Number
  • Stratified Fluids
  • Turbulent Flow
  • Turbulent Mixing
  • Two Dimensional

Fields of Study

  • Physics

Readers

  • Fluid Mechanics and Fluid Dynamics.
  • Wave Propagation and Nonlinear Chaotic Dynamics.

Technology Areas

  • Directed Energy