Boundary Effects of Uniform Size Roughness Elements in Two-Dimensional Flow in Open Channels

Abstract

Tests were conducted to investigate the characteristics of the vertical velocity distribution in flow in wide channels with large relative roughness. The study was basically a two-dimensional investigation of the boundary roughness effects in turbulent flow. The investigation was conducted in a 48-ft-long, 2-1/2-ft-wide flume with 1/8-, 1/2-, 3/4-, and 1-in. crushed limestone and 3/4-in. concrete cubes as the boundary roughness. Results indicate that the root-mean-square value of the boundary roughness heights is related to the Nikuradse equivalent sand grain roughness and that the root-mean-square value can be treated as a roughness parameter for boundaries of densely spaced, irregular, randomly placed roughness elements of uniform size. Appendix A includes the experimental data. Appendix B describes the special instrumentation used for measuring the vertical velocity profiles within the flow.

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Document Details

Document Type
Technical Report
Publication Date
Dec 01, 1968
Accession Number
AD0723984

Entities

People

  • Bobby J. Brown
  • Yen H. Chu

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Accuracy
  • Boundary Layer
  • Channel Flow
  • Containers
  • Engineers
  • Experimental Data
  • Froude Number
  • Measurement
  • Particles
  • Pitot Tubes
  • Pressure Distribution
  • Pressure Transducers
  • Shape
  • Test Facilities
  • Turbulent Flow
  • Two Dimensional
  • Two Dimensional Flow

Readers

  • Coastal and Marine Engineering/Sediment Transport/Hydraulic Engineering
  • Fluid Dynamics.
  • Geotechnical Engineering.

Technology Areas

  • Space
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