INCIPIENT JUMP CONDITION FOR VENTILATED SILL FLOW

The incipient jump condition over continuous, rectangular sills is analyzed for fully ventilated flow at the rear side of a sill. The condition examined corresponds to the limiting sill height, for which the surface profile still remains continuous and the flow is thoroughly supercritical. Slightly augmenting the sill height for fixed approaching conditions results in a local surface discontinuity, e.g. the incipient configuration of a hydraulic jump controlled by the sill. The drag coefficient of the sill is determined using the gravity-free Rethy solution. Application of the longitudinal momentum theorem then allows predicting the limiting relative sill height for gravity flow in terms of the approaching Froude number, provided critical flow is assumed at the maximum water rise. The result is compared with observations collected in two rectangular channels, the first having a drop after the sill, while the sill is mounted on a horizontal bottom in the second channel. It is found that both configurations follow the same main trend and agree fairly well with the prediction.

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/oclc/8672558
• Corporate Authors:

  American Society of Civil Engineers

  345 East 47th Street
  New York, NY  United States  10017-2398
• Authors:
  • Hager, W H
  • Basler, B
  • Wanoschenk, R
• Publication Date: 1986-10

Media Info

• Features: Appendices; Figures; Photos; References;
• Pagination: p. 953-963
• Serial:
  • Journal of Hydraulic Engineering
  • Volume: 112
  • Issue Number: 10
  • Publisher: American Society of Civil Engineers
  • ISSN: 0733-9429
  • Serial URL: https://ascelibrary.org/journal/jhend8

Subject/Index Terms

• TRT Terms: Coefficients; Creep; Drag; Flow; Froude number; Height; Hydraulic jump; Momentum; Ventilation systems
• Uncontrolled Terms: Discontinuity; Longitudinal
• Old TRIS Terms: Gravity flow; Sills
• Subject Areas: Highways; Hydraulics and Hydrology; I26: Water Run-off - Freeze-thaw;

Filing Info

• Accession Number: 00458475
• Record Type: Publication
• Report/Paper Numbers: ASCE Paper 20991
• Files: TRIS
• Created Date: Oct 31 1986 12:00AM