Flow Characteristics of Skimming Flows in Stepped Channels
This article has a reply.
VIEW THE REPLYThis article has a reply.
VIEW THE REPLYThis article has a reply.
VIEW THE REPLYPublication: Journal of Hydraulic Engineering
Volume 130, Issue 9
Abstract
Skimming flows in stepped channels are systematically investigated under a wide range of channel slopes (5.7°⩽θ⩽55°). The flow conditions of skimming flows are classified into two flow regimes, and the hydraulic conditions required to form a quasi-uniform flow are determined. An aerated flow depth of a skimming flow is estimated from the assumption that the residual energy at the end of a stepped channel coincides with the energy at the toe of the jump formed immediately downstream of the stepped channel. In a quasi-uniform flow region, the friction factor of skimming flows is represented by the relative step height and the channel slope. The friction factor for the channel slope of θ=19° appears to have a maximum. The residual energy of skimming flows is formulated for both nonuniform and quasi-uniform flow regions. Further, a hydraulic-design chart for a stepped channel is presented.
Get full access to this article
View all available purchase options and get full access to this article.
References
Boes, R. M. (2000a). “Scale effects in modelling two-phase stepped spillway flow.” Proc., Int. Workshop on Hydraulics of Stepped Spillways, Zürich, Switzerland, Balkema, Rotterdam, The Netherlands, 53–60.
Boes, R. M. (2000b). “Zweiphasenströmung und energieumsetzung auf grosskaskaden.” PhD thesis, ETH, Zürich, Switzerland (in German).
Boes, R. M., and Hager, W. H. (1998). “Fiber-optical experimentation in two-phase cascade flow.” Proc., Int. RCC Dams Seminar, Denver.
Boes, R. M., and Minor, H.-E. (2000). “Guidelines for the hydraulic design of stepped spillways.” Proc., Int. Workshop on Hydraulics of Stepped Spillways, Zürich, Switzerland, Balkema, Rotterdam, The Netherlands, 163–170.
Boes, R. M., and Minor, H.-E.(2002). “Hydraulic design of stepped spillways for RCC dams.” Hydropower Dams, 9(3), 87–91.
Chamani, M. R., and Rajaratnam, N.(1999). “Characteristics of skimming flow over stepped spillways.” J. Hydraul. Eng., 125(4), 361–368.
Chanson, H. (2001). The hydraulics of stepped chutes and spillways, Balkema, Lisse, The Netherlands.
Chanson, H.(2002). “Air-water flow measurements with intrusive phase-detection probes. Can we improve their interpretation?” J. Hydraul. Eng., 128(3), 252–255.
Chanson, H., and Toombes, L.(2002). “Air-water flows down stepped chutes: turbulence and flow structure observations.” Int. J. Multiphase Flow, 27(11), 1737–1761.
Chanson, H., Yasuda, Y., and Ohtsu, I.(2002). “Flow resistance in skimming flows and its modelling.” Can. J. Civ. Eng., 29(6), 809–819.
Chow, V. T. (1959). Open channel hydraulics, McGraw–Hill, New York.
Christodoulou, G. C.(1993). “Energy dissipation on stepped spillways.” J. Hydraul. Eng., 119(5), 644–650.
Matos, J.(2000). “Discussion of ‘characteristics of skimming flow over stepped spillways.’” J. Hydraul. Eng., 126(11), 865–869.
Ohtsu, I., and Yasuda, Y. (1997). “Characteristics of flow conditions on stepped channels.” Proc., 27th IAHR Congress, San Francisco, 583–588.
Ohtsu, I., Yasuda, Y., and Takahashi, M.(2000a). “Discussion of ‘characteristics of skimming flow over stepped spillways.’ ”J. Hydraul. Eng., 126(11), 869–871.
Ohtsu, I., Yasuda, Y., and Takahashi, M.(2000b). “Discussion of ‘hydraulics of skimming flow on modeled stepped spillways.’” J. Hydraul. Eng., 126(12), 950–951.
Ohtsu, I., Yasuda, Y., and Takahashi, M.(2001). “Discussion of ‘onset of skimming flow on stepped spillways.’” J. Hydraul. Eng., 127(6), 522–524.
Sorensen, R. M.(1985). “Stepped spillway hydraulic model investigation.” J. Hydraul. Eng., 111(12), 1461–1472.
Yasuda, Y., and Chanson, H. (2003). “Micro- and macro-scopic study of two-phase flow on a stepped chute.” Proc., 30th IAHR Congress, Thessaloniki, Greece, 695–702.
Yasuda, Y., and Ohtsu, I. (1999). “Flow resistance of skimming flows in stepped channels.” Proc., 28th IAHR Congress (CD-ROM), Graz, Austria.
Yasuda, Y., Takahashi, M., and Ohtsu, I. (2001). “Energy dissipation of skimming flows on stepped-channel chutes.” Proc., 29th IAHR Congress, Beijing, 531–536.
Information & Authors
Information
Published In
Journal of Hydraulic Engineering
Volume 130 • Issue 9 • September 2004
Pages: 860 - 869
Copyright
Copyright © 2004 American Society of Civil Engineers.
History
Received: May 7, 2003
Accepted: Feb 16, 2004
Published online: Aug 16, 2004
Published in print: Sep 2004
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.