THE DESIGN OF SUPERCRITICAL FLOW CHANNEL JUNCTIONS

THE PURPOSE OF THE PAPER IS TO DISCUSS THE DIAGONAL WAVE AND PILE-UP PROBLEMS WHICH RESULT FROM THE INTERSECTION OF TWO OPEN CHANNELS, EACH CARRYING WATER AT SUPERCRITICAL VELOCITIES. METHODS ARE SET FORTH FOR THE DETERMINATION OF THE HEIGHT OF WALL PILE-UP WHICH OCCURS UNDER CONDITIONS OF DESIGN FLOW AND UNDER THE UNBALANCED CONDITIONS OF FLOW IN ONLY ONE OF THE CHANNELS. FOR THE DETERMINATION OF PILE-UP HEIGHT FOR THESE CONDITIONS IT IS NECESSARY TO REFER TO LABORATORY CURVES WHICH ARE INCLUDED. A CHANNEL JUNCTION DESIGN IS SUGGESTED WHICH HAS MINIMIZED THE WAVE PROBLEM IN LABORATORY EXPERIMENTS. THE JUNCTION DIFFERS FROM THE SIMPLE CHANNEL JUNCTION IN TWO WAYS. THE MAIN CHANNEL IS WIDENED AT THE JUNCTION TO ACCOMMODATE THE INCREASED DISCHARGE CONTRIBUTED BY THE SIDE CHANNEL, AND A BAFFLE, WHICH IS ACTUALLY ONLY AN EXTENSION OF THE MAIN CHANNEL WALL, IS EXTENDED DOWNSTREAM IN FRONT OF THE SIDE CHANNEL. THIS BAFFLE IS RECOMMENDED TO BE TAPERED AT A SLOPE EQUAL TO THE GREATER OF THE FROUDE NUMBERS IN THE MAIN OR SIDE CHANNELS, DIVIDED BY 50. SMALLER RATES OF TAPER ARE ACCEPTABLE, BUT MORE PRONOUNCED TAPERS RESULT IN PILE-UP PROBLEMS ON THE CHANNEL SIDES. THIS TYPE OF JUNCTION RESULTS IN ALMOST NO WAVE PROBLEM UNDER DESIGN CONDITIONS OF FLOW IN BOTH CHANNELS AND IT RESULTS IN LOW PILE-UP DEPTHS FOR CONDITIONS OF FLOW ONLY IN ONE CHANNEL OR THE OTHER. /AUTHOR/

• Record URL:
  http://onlinepubs.trb.org/Onlinepubs/hrr/1966/123/123-002.pdf
• Supplemental Notes:
  • Paper sponsored by Committee on Surface Drainage of Highways and presented at the 45th Annual Meeting. Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved
• Authors:
  • Behlke, Charles E
  • Pritchett, Harold D
• Publication Date: 1966

Media Info

• Media Type: Print
• Features: Figures; References;
• Pagination: pp 17-35
• Monograph Title: Highway drainage and scour studies
• Serial:
  • Highway Research Record
  • Issue Number: 123
  • Publisher: Highway Research Board

Subject/Index Terms

• TRT Terms: Backwaters; Channel flow; Channels (Waterways); Design; Flow; Height; Intersections; Laboratory studies; Open channels; Pavement widening; Rivers; Supersonic flow; Turbulence; Wave motion
• Candidate Terms: Turbulent flow
• Uncontrolled Terms: Baffles; Open channel flow; Trapezoidal channels; Widening
• Old TRIS Terms: Channel control /river/
• Subject Areas: Design; Highways; Hydraulics and Hydrology;

Filing Info

• Accession Number: 00203948
• Record Type: Publication
• Files: TRIS, TRB
• Created Date: Nov 21 1994 12:00AM