BED FORMS AND FRICTION IN STREAMS

EXPERIMENTS WERE MADE IN FLUMES WITH RIPPLED BEDS TO DETERMINE THE RELATION BETWEEN THE FRICTION FACTOR AND GEOMETRIC PARAMETERS OF THE RIPPLES. THIS OBJECTIVE WAS ACHIEVED WITH REASONABLE SUCCESS FOR BEDS WITH RIPPLES OF LOW STEEPNESS BY USING THE PRODUCT EH AS A CHARACTERISTIC ROUGHNESS LENGTH IN WHICH H IS THE MEAN RIPPLE HEIGHT AND E IS THE FRACTION OF THE BED AREA OCCUPIED BY THE HORIZONTAL PROJECTION OF THE STEEP LEE SLOPES OF THE RIPPLES. A LESS SATISFACTORY RELATION FOR THE FRICTION FACTOR FOR THE AUTHORS' DATA WAS OBTAINED WHEN H SQUARE/L WAS USED FOR THE ROUGHNESS LENGTH, IN WHICH L IS THE MEAN RIPPLE LENGTH. WITH THE LATTER ROUGHNESS LENGTH, CORRELATIONS OF FRICTION FACTOR DATA BY SEVERAL WORKERS FOR BOTH RIPPLES AND DUNES WAS ONLY MODERATELY SUCCESSFUL. EXPERIMENTS SHOWED THAT THE RIPPLE BEDS WERE HYDRODYNAMICALLY ROUGH. THE FRICTION FACTORS OF STABILIZED BEDS AND THE PRESSURE COEFFICIENT OVER A TYPICAL RIPPLE WERE INDEPENDENT OF THE REYNOLDS NUMBER AND WERE DEPENDENT ONLY ON FLOW DEPTH. /ASCE/

• Supplemental Notes:
  • Vol 93, No HY3, PP 121-144, 7 FIG, 7TAB, 1 APP
• Authors:
  • Vanoni, V A
  • Hwang, L S
• Publication Date: 1967-5

Media Info

• Serial:
  • Journal of the Hydraulics Division
  • Publisher: American Society of Civil Engineers

Subject/Index Terms

• TRT Terms: Depth; Flow; Flumes; Friction factor; Geometric design; Hydrodynamics; Roughness; Streambeds; Water pressure
• Old TRIS Terms: Ripples
• Subject Areas: Highways; Hydraulics and Hydrology;

Filing Info

• Accession Number: 00204087
• Record Type: Publication
• Files: TRIS
• Created Date: Jul 21 1994 12:00AM