Channel Shape and Turbulence Issues in Flood Flow Hydraulics
Publication: Journal of Hydraulic Engineering
Volume 131, Issue 10
Abstract
This paper reports the results of some further reflections by the writer on the nature of the flow physics in flooded channels where the floodplain flow overtops that in the main channel. A lot of the early conclusions drawn on this issue come from results of the Flood Channel Facility (FCF) program carried in the United Kingdom in the 1990s, but also from numerical work such as that of the writer. This paper takes this work further and reports that the FCF geometry may have led to conclusions that are dependent on a channel layout that is not fully representative of nature. It indicates that the flow structure evolves as a function of the channel width-to-depth ratio, and requires different turbulence model approaches to be computed accurately as this happens. In particular the standard is shown to become less adequate. It is also shown that the bank slope is influential in determining the flow structure, and that the flatter the slope the more likely it is to present increasing difficulties for modeling.
Get full access to this article
View all available purchase options and get full access to this article.
Acknowledgments
The writer would like to thank Dr. Florian Menter from CFX Germany for his comments and pictures as well as Professor Alan Ervine, The University of Glasgow, for his information regarding the FCF geometry.
References
Ahmed, S. R., Ramm, G., and Faltin, G. (1984). “Some salient features of the time-averaged ground vehicle wake.” SAE Technical Paper 840300.
Blench, T. (1952). “Regime theory for self-formed sediment-bearing channels.” Trans. Am. Soc. Civ. Eng., 117, 383–408.
Blench, T. (1970). “Regime theory design of canals with sand beds.” J. Irrig. Drain. Eng., 96(2), 205–213.
Chang, H. H. (1988). Fluvial processes in river engineering, Krieger, Malabar, Fla.
Cokljat, D., and Younis, B. A. (1995). “Compound channel flows: A parametric study using a Reynolds-stress transport closure.” J. Hydraul. Res., 33(3), 307–320.
Kellerhals, R., Neill, C. R., and Bray, D. I. (1972). “Hydraulic and geomorphic characteristics of rivers in Alberta.” River Engineering and Surface Hydrology Rep., Research Council of Alberta, Alberta, Canada.
Lienhart, H., Stoots, C., and Becker, S. (2000). “Flow and turbulence structures in the wake of a simplified car model (Ahmed model).” Proc., DGLR Fach Symp. der AG-Stab, Stuttgart Univ., Stuttgart, Germany.
Menter, F. R., and Kuntz, M. (2003). “Development and application of a zonal DES turbulence model for CFX-5.” CFX Internal Rep., Otterfing, Germany.
Morvan, H. P. (2001). “Three-dimensional simulation of river flood flows.” PhD thesis, The Univ. of Glasgow, Glasgow, U.K.
Morvan, H. P., Pender, G., Wright, N. G., and Ervine, D. A. (2002). “Three-dimensional hydrodynamics of meandering compound channels.” J. Hydraul. Eng., 128(7), 674–682.
Pender, G., Morvan, H. P., Wright, N. G., and Ervine, D. A. (2005). “CFD applications for environmental management/engineering.” CFD applications in rivers and estuaries, Bates, Ferguson, and Lane, eds., Wiley, Chichester, U.K.
Principe, J. (2003). “2D backward facing step.” Proc., 3rd QNET-CFD Workshop, Prague, Czechoslovakia, ⟨http:∕∕www.qnet-cfd.net⟩
Speziale, C. G., Sarkar, S., and Gatski, T. B. (1991). “Modelling the pressure-strain correlation of turbulence: An invariant dynamical systems approach.” J. Fluid Mech., 227, 245–272.
Information & Authors
Information
Published In
Copyright
© 2005 ASCE.
History
Received: Oct 21, 2003
Accepted: Dec 1, 2004
Published online: Oct 1, 2005
Published in print: Oct 2005
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.