Side-Channel Flow: Physical Model Studies
Publication: Journal of Hydraulic Engineering
Volume 141, Issue 9
Abstract
Hydraulic investigations of three hydraulic model studies on side channels are presented. These include the side channels of the Trängslet Dam, Sweden, the Kárahnjúkar Dam, Iceland, and the Lyssbach diversion tunnel, Switzerland, of which the former two have a trapezoidal cross section and the latter has a rectangular cross section. The observed flow patterns are described, with particular attention on the single- and two-vortex spiral flow patterns, the formation of a tornado vortex, and air entrainment. The measured streamwise free-surface profiles are compared with one-dimensional computations on the basis of the standard spatially varied flow equation. Although a good agreement results in general, deviations are primarily explained by local perturbations. The measured cross-sectional free-surface profiles indicate an increase in the flow depth along the side walls compared with the computed flow depth at the impact point of lateral inflow. For the side-channel design, safety provisions should therefore be considered. Side channels with geometrical complexities and a high hazard potential should be investigated in detailed hydraulic model tests, whereas the remainder essentially follows computations on the basis of the preceding procedure.
Get full access to this article
View all available purchase options and get full access to this article.
Acknowledgments
The authors kindly thank Fortum Generation AB (Trängslet), Landsvirkjun (Kárahnjúkar), and the Bernese Public Works (Lyssbach) for their excellent collaboration.
References
Boes, R. M., Lutz, N., Lais, A., and Lucas, J. (2013). “Hydraulic modelling of floating debris conveyance for a spillway upgrade at a large rockfill dam.” Proc., 9th ICOLD European Club Symp., Venice, Italy.
Bremen, R., and Hager, W. H. (1989). “Experiments in side-channel spillways.” J. Hydraul. Eng., 617–635.
Bremen, R., and Hager, W. H. (1990). “Flow features in side-channel spillways.” 12th Convegno di Idraulica e Costruzioni Idrauliche, BIOS, Cosenza, Italy, 91–105.
Camp, T. R. (1940). “Lateral spillway channels.” Trans. Am. Soc. Civ. Eng., 105(1), 606–617.
Chow, V. T. (1959). Open channel hydraulics, McGraw-Hill, New York.
Citrini, D. (1942). “Canali rettangolari con portata e larghezza gradualmente variabili (rectangular channels with linearly varied discharge and width).” L’Energia Elettrica, 19(6), 297–301 (in Italian).
Citrini, D. (1948). “Canali rettangolari con apporto laterale di portata (rectangular channels with spatially-varied discharge).” L’Energia Elettrica, 25(4), 155–166 (in Italian).
De Marchi, G. (1941). “Canali con portata progressivamente crescente (channels with progressively increasing discharge).” L’Energia Elettrica, 18(6), 351–360 (in Italian).
Favre, H. (1932). Contribution à l’étude des courants liquides (contribution to the study of liquid currents), Rascher, Zurich, Switzerland (in French).
Guercio, R., and Magini, R. (1994). “Effect of the lateral discharge in side-channels: Experimental and numerical modelling.” Giornale del Genio Civile, 132(1–3), 47–67 (in Italian).
Hager, W. H. (2010). Wastewater hydraulics: Theory and practice, 2nd Ed., Springer, Berlin.
Hager, W. H., Edder, O., and Rappaz, J. (1988). “Streamline curvature effects in side-channel spillway flow.” Acta Mech., 72(1–2), 95–110.
Hinds, J. (1926). “Side channel spillways: Hydraulic theory, economic factors, and experimental determination of losses.” Trans. Am. Soc. Civ. Eng., 89(1), 881–927.
Keulegan, G. H. (1950). “Determination of critical depth in spatially-variable flow.” 1st Midwestern Conf. on Fluid Mechanics, Edwards, Ann Arbor, MI, 68–80.
Li, W.-H. (1955). “Open channels with nonuniform discharge.” Trans. Am. Soc. Civ. Eng., 120(1), 255–274.
Liggett, J. A. (1961). “General solution for open channel profiles.” J. Hydr. Div., 87(6), 89–107.
McConaughy, D. C. (1933). “Spillways in canyon walls to handle floodwaters.”, 480–482.
Meyer-Peter, E., and Favre, H. (1934). “Analysis of Boulder Dam spillways made by Swiss laboratory.”, 520–522.
Pfister, M., Berchtold, T., and Lais, A. (2008). “Kárahnjúkar dam spillway: Optimization by hydraulic model tests.” 3rd IAHR Int. Symp. Hydraulic Structures, Vol. 6, Hohai Univ., Nanjing, China, 2106–2111.
Pfister, M., and Rühli, E. (2011). “Junction flow between drop shaft and diversion tunnel in Lyss, Switzerland.” J. Hydraul. Eng., 836–842.
Sassoli, F. (1959). “Canali collettori laterali a forte pendenza (side-channels with a strong bottom slope).” L’Energia Elettrica, 36(1), 26–39 (in Italian).
Tomasson, G. G., Gardarsson, S. M., Petry, B., and Stefansson, B. (2006). “Design challenges and solutions for the Kárahnjúkar spillway.” Int. J. Hydropower Dams, 13(5), 84–89.
Unami, K., Kawachi, T., Munir Babar, M., and Itagaki, H. (1999). “Two-dimensional numerical model of spillway flow.” J. Hydraul. Eng., 125(4), 369–375.
USBR (U.S. Bureau of Reclamation). (1938). “Model studies of spillways.” Bulletin 1. Boulder Canyon Project, Final Rep. Part VI: Hydraulic Investigations, U.S. Dept. of the Interior, Denver.
USBR (U.S. Bureau of Reclamation). (1960). Design of small dams, Denver.
Vischer, D. L., and Hager, W. H. (1998). Dam hydraulics, Wiley, Chichester, U.K.
Yen, B. C. (1973). “Open-channel flow equations revisited.” J. Engrg. Mech. Div., 99(5), 979–1009.
Information & Authors
Information
Published In
Journal of Hydraulic Engineering
Volume 141 • Issue 9 • September 2015
Copyright
© 2015 American Society of Civil Engineers.
History
Received: Jun 27, 2014
Accepted: Mar 2, 2015
Published online: May 18, 2015
Published in print: Sep 1, 2015
Discussion open until: Oct 18, 2015
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.