Hydraulic Performance of an Embankment Weir with Rough Crest
This article has a reply.
VIEW THE REPLYThis article has a reply.
VIEW THE REPLYPublication: Journal of Hydraulic Engineering
Volume 143, Issue 3
Abstract
An experimental study was conducted on a large embankment weir with smooth and rough crests for a range of flow conditions . Close agreement between the rough and smooth crest experiments was observed in terms of flow patterns, free-surface profiles, and pressure distributions. The crest roughness had effects on the velocity distributions, the boundary layer properties, and the shear stress. On the rough crest, the velocity distributions were shifted upwards, increasing the growth rate of the boundary layer. The calculation of the shear stresses with the law of the wall, outer flow region, and momentum integral methods showed consistent results of about for the smooth crest and of for the rough crest. The crest roughness reduced the discharge performance, while upstream and downstream ramps did not have any effects. The present observations highlighted the relevance of roughness and scaling on the hydraulic performances of weirs.
Get full access to this article
View all available purchase options and get full access to this article.
Acknowledgments
The authors thank Martin Fong (UNSW Australia) for the collection of some of the experimental data. They thank Larry Paice and Rob Jenkins (WRL, UNSW Australia) for their technical assistance.
References
Azimi, A., Rajaratnam, N., and Zhu, D. (2013). “Discharge characteristics of weirs of finite crest length with upstream and downstream ramps.” J. Irrig. Drain. Eng., 75–83.
Bazin, H. (1896). “Expériences nouvelles sur l’ecoulement par déversoir [recent experiments on the flow of water over weirs].” Annales des Ponts et Chaussées, Paris (in French).
Blasius, H. (1913). “Das Ähnlichkeitsgesetz bei Reibungsvorgängen in Flüssigkeiten: über den Gültigkeitsbereich der beiden Ähnlichkeitsgesetze in der Hydraulik.” Mitteilung 131 über Forschungsarbeiten auf dem Gebiete des Ingenieurwesens, Springer, Berlin (in German).
Bos, M. G. (1976). “Discharge measurement structures.”, Laboratorium voor Hydraulica an Afvoerhydrologie, Landbouwhogeschool, Wageningen, Netherlands.
Castro-Orgaz, O., and Chanson, H. (2014). “Depth-averaged specific energy in open-channel flow and analytical solution for critical irrotational flow over weirs.” J. Irrig. Drain. Eng., .
Chanson, H. (2000). “Boundary shear stress measurements in undular flows: Application to standing wave bed forms.” Water Resour. Res., 36(10), 3063–3076.
Chanson, H. (2014). Applied hydrodynamics: An introduction, CRC Press, Leiden, Netherlands.
Creager, W. P. (1917). Engineering of masonry dams, Wiley, New York.
Ehrenberger, R. (1929). “Versuche über die Verteilung der Drücke an Wehrrücken infolge des abstürzenden Wassers.” Die Wasserwirtschaft, 22(5), 65–72 (in German).
Felder, S., and Chanson, H. (2012). “Free-surface profiles, velocity and pressure distributions on a broad-crested weir: A physical study.” J. Irrig. Drain. Eng., 1068–1074.
Fritz, H., and Hager, W. (1998). “Hydraulics of embankment weirs.” J. Hydraul. Eng., 963–971.
Gonzalez, C. A., and Chanson, H. (2007). “Experimental measurements of velocity and pressure distribution on a large broad-crested weir.” Flow Meas. Instrum., 18(3–4), 107–113.
Güven, O., Farell, C., and Patel, V. C. (1980). “Surface-roughness effects on the mean flow past circular cylinders.” J. Fluid Mech., 98(4), 673–701.
Hager, W., and Schwalt, M. (1994). “Broad-crested weir.” J. Irrig. Drain. Eng., 13–26.
Harrison, A. J. M. (1967). “The streamlined broad-crested weir.” ICE Proc., 38(4), 657–678.
Henderson, F. M. (1966). Open channel flow, MacMillan, New York.
Hopkins, A., and Simpson, R. (2009). “Fluid dynamics and surface pressure fluctuations of dense rough surface turbulent boundary layers.” Proc., 47th AIAA Aerospace Sciences Meeting, AIAA, Reston, VA.
Horton, R. E. (1907). “Weir experiments, coefficients, and formulas.” U.S. Dept. of Interior, Government Printing Office, Washington, DC.
Kindsvater, C. E. (1964). “Discharge characteristics of embankment shaped weirs.” Geological Survey Water Supply, U.S. Government Printing Office, Washington, DC.
Montes, J. S. (1994). “Potential flow solution to the 2D transition from mild to steep slope.” J. Hydraul. Eng., 601–621.
Montes, J. S. (1998). Hydraulics of open channel flow, ASCE, Reston, VA.
Moss, W. D. (1972). “Flow separation at the upstream edge of a square-edged broad-crested weir.” J. Fluid Mech., 52(2), 307–320.
Novak, P., Moffat, A. I. B., Nalluri, C., and Narayanan, R. (1996). Hydraulic structures, 2nd Ed., E&FN Spon, London.
Parilkova, J., Riha, J., and Zachoval, Z. (2012). “The influence of roughness on the discharge coefficient of a broad-crested weir.” J. Hydrol. Hydromech., 60(2), 101–114.
Ramamurthy, A. S., Tim, U. S., and Rao, M. V. J. (1988). “Characteristics of square-edged and round-nosed broad-crested weirs.” J. Irrig. Drain. Eng., 61–73.
Rao, N. G., and Muralidhar, D. (1963). “Discharge characteristics of weirs of finite crest width.” La Houille Blanche, 18(5), 537–545.
Rouse, H. (1936). “Discharge characteristics of the free overfall.” Civ. Eng., 6(4), 257–260.
Sargison, J. E., and Percy, A. (2009). “Hydraulics of broad-crested weirs with varying side slopes.” J. Irrig. Drain. Eng., 115–118.
Schlichting, H. (1979). Boundary layer theory, 7th Ed., McGraw-Hill, New York.
Scimemi, E. (1930). “Sulla Forma delle Vene Tracimanti [The form of flow over weirs].” L’Energia Elettrica, Milan, 7(4), 293–305 (in Italian).
Tracy, H. J. (1957). “Discharge characteristics of broad-crested weirs.”, U.S. Dept. of Interior, Washington, DC.
Vierhout, M. M. (1973). “On the boundary layer development in round broad-crested weirs with a rectangular control section.”, Laboratory of Hydraulics and Catchment Hydrology, Agricultural Univ., Wageningen, Netherlands.
Zerihun, Y. T., and Fenton, J. D. (2007). “A Boussinesq-type model for flow over trapezoidal profile weirs.” J. Hydraul. Res., 45(4), 519–528.
Information & Authors
Information
Published In
Journal of Hydraulic Engineering
Volume 143 • Issue 3 • March 2017
Copyright
©2016 American Society of Civil Engineers.
History
Received: May 23, 2016
Accepted: Aug 5, 2016
Published online: Oct 10, 2016
Published in print: Mar 1, 2017
Discussion open until: Mar 10, 2017
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.