Aeration, Flow Instabilities, and Residual Energy on Pooled Stepped Spillways of Embankment Dams
This article has a reply.
VIEW THE REPLYThis article has a reply.
VIEW THE REPLYPublication: Journal of Irrigation and Drainage Engineering
Volume 139, Issue 10
Abstract
Air-water flow experiments were conducted on some flat and pooled stepped spillways with slopes of 8.9° and 26.6° in transition and skimming flows. The study comprised the observations of the flow patterns, characteristic air-water flow properties, and energy dissipation performances. The air-water flow properties showed some differences in terms of interfacial velocity, bubble count rate, and turbulence intensity between the stepped chutes for the two channel slopes. These differences were also reflected in the residual energy data, highlighting a better energy dissipation rate for the pooled stepped spillway with slope of 8.9°. However, the aerated flows on the pooled stepped spillways exhibited some hydrodynamic instabilities, and a safe operation must be tested in physical models. The flat stepped spillway appeared to be the preferable design in terms of energy dissipation and flow stability.
Get full access to this article
View all available purchase options and get full access to this article.
Acknowledgments
The authors thank Professor Holger Schüttrumpf (IWW, RWTH Aachen University) for providing access to the experimental facility and Jason Van Der Gevel and Stewart Matthews (The University of Queensland) for their technical assistance. The financial supports through a UQ research scholarship and through the Australian Research Council (Grant DP120100481) are acknowledged.
References
André, S. (2004). “High velocity aerated flows on stepped chutes with macro-roughness elements.” Ph.D. thesis, Laboratoire de Constructions Hydraulics (LCH), EPFL, Lausanne, Switzerland.
Carosi, G., and Chanson, H. (2006). “Air-water time and length scales in skimming flow on a stepped spillway. Application to the spray characterisation.”, Division of Civil Engineering, Univ. of Queensland, Brisbane, Australia.
Chanson, H. (1995). “Air bubble entrainment in free-surface turbulent flows. Experimental investigations.” Rep. CH46/95, Dept. of Civil Engineering, Univ. of Queensland, Brisbane Australia.
Chanson, H. (2001). The hydraulics of stepped chutes and spillways, Balkema, Lisse, Netherlands.
Chanson, H., and Toombes, L. (2002a). “Energy dissipation and air entrainment in stepped storm waterway: Experimental study.” J. Irrig. Drain. Eng., 128(5), 305–315.
Chanson, H., and Toombes, L. (2002b). “Air-water flows down stepped chutes: Turbulence and flow structure observations.” Int. J. Multiphase Flow, 28(11), 1737–1761.
Chanson, H., Yasuda, Y., and Ohtsu, I. (2002). “Flow resistance in skimming flows and its modelling.” Can. J. Civil Eng., 29(6), 809–819.
Ditchey, E. J., and Campbell, D. B. (2000). “Roller compacted concrete and stepped spillways.” Int. Workshop on Hydraulics of Stepped Spillways, Balkema, Leiden, Netherlands, 171–178.
Felder, S. (2013). “Air-water flow properties on stepped spillways for embankment dams: Aeration, energy dissipation and turbulence on uniform, non-uniform and pooled stepped chutes.” Ph.D. thesis, School of Civil Engineering, Univ. of Queensland, Brisbane, Australia.
Felder, S., and Chanson, H. (2012a). “Free-surface profiles, velocity and pressure distributions on a broad-crested weir: A physical study.” J. Irrig. Drain. Eng., 138(12), 1068–1074.
Felder, S., and Chanson, H. (2012b). “Air-water flow measurements in instationary free-surface flows: A triple decomposition technique.”, School of Civil Engineering, Univ. of Queensland, Brisbane, Australia.
Felder, S., Fromm, C., and Chanson, H. (2012a). “Air entrainment and energy dissipation on a 8.9° slope stepped spillway with flat and pooled steps.”, School of Civil Engineering, Univ. of Queensland, Brisbane, Australia.
Felder, S., Guenther, P., and Chanson, H. (2012b). “Air-water flow properties and energy dissipation on stepped spillways: A physical study of several pooled stepped configurations.”, School of Civil Engineering, Univ. of Queensland, Brisbane, Australia.
Hansen, K. D., and Reinhardt, K. D. (1991). Roller-compacted concrete dams, McGraw-Hill, New York.
Henderson, F. M. (1966). Open channel flow, MacMillan, New York.
Hunt, S., and Kadavy, K. (2013). “Inception point for embankment dam stepped spillways.” J. Hydraul. Eng., 139(1), 60–64.
Kökpinar, M. A. (2004). “Flow over a stepped chute with and without macro-roughness elements.” Can. J. Civil Eng., 31(5), 880–891.
Meireles, I., and Matos, J. (2009). “Skimming flow in the nonaerated region of stepped spillways over embankment dams.” J. Hydraul. Eng., 135(8), 685–689.
Takahashi, M., Yasuda, Y., and Ohtsu, I. (2008). “Flow patterns and energy dissipation over various stepped chutes. discussion.” J. Irrig. Drain. Eng., 134(1), 114–116.
Thorwarth, J. (2008). “Hydraulisches Verhalten der Treppengerinne mit eingetieften Stufen—Selbstinduzierte Abflussinstationaritäten und Energiedissipation [Hydraulics of pooled stepped spillways—Self-induced unsteady flow and energy dissipation].” Ph.D. thesis, Univ. of Aachen, Aachen, Germany (in German).
Toombes, L. (2002). “Experimental study of air-water flow properties on low-gradient stepped cascades.” Ph.D. thesis, Dept. of Civil Engineering, Univ. of Queensland, Brisbane, Australia.
Toombes, L., and Chanson, H. (2008). “Flow patterns in nappe flow regime down low gradient stepped chutes.” J. Hydraul. Res., 46(1), 4–14.
Information & Authors
Information
Published In
Journal of Irrigation and Drainage Engineering
Volume 139 • Issue 10 • October 2013
Pages: 880 - 887
Copyright
© 2013 American Society of Civil Engineers.
History
Received: Dec 6, 2012
Accepted: Apr 17, 2013
Published online: Apr 19, 2013
Discussion open until: Sep 19, 2013
Published in print: Oct 1, 2013
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.