BOUNDARY EFFECTS OF UNIFORM SIZE ROUGHNESS ELEMENTS IN TWO-DIMENSIONAL FLOW IN OPEN CHANNELS

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 34-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. (Author)

  • Corporate Authors:

    U.S. Army Waterways Experiment Station

    3909 Halls Ferry Road
    Vicksburg, MS  USA  39180-6199
  • Authors:
    • Brown, B J
    • Chu, Y H
  • Publication Date: 1968-12

Media Info

  • Pagination: 72 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00019399
  • Record Type: Publication
  • Source Agency: National Technical Information Service
  • Report/Paper Numbers: AEWES-MiscPaperH68-5
  • Files: TRIS
  • Created Date: Nov 19 1971 12:00AM