Redistribution of Velocity and Bed-Shear Stress in Straight and Curved Open Channels by Means of a Bubble Screen: Laboratory Experiments
Publication: Journal of Hydraulic Engineering
Volume 134, Issue 2
Abstract
Open-channel beds show variations in the transverse direction due to the interaction between downstream flow, cross-stream flow, and bed topography, which may reduce the navigable width or endanger the foundations of structures. The reported preliminary laboratory study shows that a bubble screen can generate cross-stream circulation that redistributes velocities and hence, would modify the topography. In straight flow, the bubble-generated cross-stream circulation cell covers a spanwise extent of about four times the water depth and has maximum transverse velocities of about . In sharply curved flow, it is slightly weaker and narrower with a spanwise extent of about three times the flow depth. It shifts the counter-rotating curvature-induced cross-stream circulation cell in the inwards direction. Maximum bubble-generated cross-stream circulation velocities are of a similar order of magnitude to typical curvature-induced cross-stream circulation velocities in natural open-channel bends. The bubble screen technique is adjustable, reversible, and ecologically favorable. Detailed data on the 3D flow field in open-channel bends is provided, which can be useful for validation of numerical models.
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Acknowledgments
Professors Uijttewaal, Booij, and Gaskin are acknowledged for their constructive comments and suggestions.
References
Batchelor, G. K. (1967). An introduction to fluid dynamics, Cambridge Univ. Press, Cambridge, U.K.
Blanckaert, K. (2002). “Flow and turbulence in sharp open-channel bends.” Ph.D. thesis No. 2545, Ecole Polytechnique Fédérale Lausanne, Switzerland, ⟨ftp://lrhmac15.epfl.ch/Pub/Thesis/Blanckaert/PhD⟩.
Blanckaert, K., and de Vriend, H. J. (2003). “Nonlinear modeling of mean flow redistribution in curved open channels.” Water Resour. Res., 39(12), 1375–1388.
Blanckaert, K., and de Vriend, H. J. (2004). “Secondary flow in sharp open-channel bends.” J. Fluid Mech., 498, 353–380.
Blanckaert, K., and Graf, W. H. (2001). “Experiments on flow in an open-channel bend. Mean flow and turbulence.” J. Hydraul. Eng., 127(10), 835–847.
Blanckaert, K., and Graf, W. H. (2004). “Momentum transport in sharp open-channel bends.” J. Hydraul. Eng., 130(3), 186–198.
Blanckaert, K., and Lemmin, U. (2006). “Means of noise reduction in acoustic turbulence measurements.” J. Hydraul. Res., 44(1), 3–17.
Bradshaw, P. (1987). “Turbulent secondary flows.” Annu. Rev. Fluid Mech., 19, 53–74.
Chow, V. T. (1959). Open-channel hydraulics, McGraw-Hill, New York.
Colombini, M. (1993). “Turbulence-driven secondary flows and formation of sand ridges.” J. Fluid Mech., 254, 701–719.
de Vriend, H. J. (1977). “A mathematical model of steady flow in curved shallow channels.” J. Hydraul. Res., 15(1), 37–54.
de Vriend, H. J. (1981). “Velocity redistribution in curved rectangular channels.” J. Fluid Mech., 107, 423–439.
Engelund, F. (1974). “Flow and bed topography in channel bends.” J. Hydr. Div., 100(HY11), 1631–1648.
Fargue, L. (1868). “Etude sur la corrélation entre la configuration du lit et la profondeur d’eau dans les rivières à fond mobile.” Annales des Ponts et Chaussées.
Hersberger, D. (2002). “Wall roughness effects on flow and scouring in curved channels with gravel bed.” Ph.D. thesis No. 2632, Ecole Polytechnique Fédérale Lausanne, Switzerland.
Hurther, D., and Lemmin, U. (1998). “A constant beamwidth transducer for three-dimensional Doppler profile measurements in open channel flow.” Meas. Sci. Technol., 9(10), 1706–1714.
Ikeda, S., and Nishimura, T. (1985). “Bed topography in bends of sand-slit rivers.” J. Hydraul. Eng., 111(11), 1397–1411.
Jaeggi, M. N. R. (1984). “Formation and effects of alternate bars.” J. Hydraul. Eng., 110(2), 142–156.
Kikkawa, H., Ikeda, S., and Kitagawa, A. (1976). “Flow and bed topography in curved open channels.” J. Hydr. Div., 102(HY9), 1327–1342.
Knaapen, M. A. F., Hulscher, S. J. M. H., de Vriend, H. J., and van Harten, A. (2001). “Height and wavelength of alternate bars in rivers: Modeling vs. laboratory experiments.” J. Hydraul. Res., 39(2), 147–153.
Leifer, I., Patro, R. K., and Bowyer, P. (2000). “A study on the temperature variation of rise velocity for large clean bubbles.” J. Atmos. Ocean. Technol., 17(10), 1392–1402.
Lemmin, U., and Rolland, T. (1997). “Acoustic velocity profiler for laboratory and field studies.” J. Hydraul. Eng., 123(12), 1089–1098.
Nezu, I., and Nakagawa, H. (1984). “Cellular secondary currents in straight conduit.” J. Hydraul. Eng., 110(2), 173–193.
Nezu, I., and Nakagawa, H. (1993). Turbulence in open-channel flows, IAHR Monograph, Balkema, Rotterdam, The Netherlands.
Odgaard, A. J. (1981). “Transverse bed slope in alluvial channel bends.” J. Hydr. Div., 107(HY12), 1677–1693.
Odgaard, A. J. (1984). “Flow and bed topography in alluvial channel bend.” J. Hydraul. Eng., 110(4), 521–536.
Odgaard, A. J., and Spoljaric, A. (1986). “Sediment control by submerged vanes.” J. Hydraul. Eng., 112(12), 1164–1181.
Odgaard, A. J., and Wang, Y. (1991). “Sediment management with submerged vanes. I: Theory.” J. Hydraul. Eng., 117(3), 267–283.
Roca, M., Martin-Vide, J. P., and Blanckaert, K. (2006). “Reduction of bend scour by an outer bank footing. Footing design and bed topography.” J. Hydraul. Eng., 133(2), 139–147.
Rozovskii, I. L. (1957). “Flow of water in bends of open channels.” Ac. Sc. Ukr. SSR, Isr. Progr. Sc. Transl., Jerusalem, Israel.
Schielen, R., Doelman, A., and Deswart, H. E. (1993). “On the nonlinear dynamics of free bars in straight channels.” J. Fluid Mech., 252, 325–356.
Sloff, C. J., Mosselman, E., and Sieben, J. (2006). “Effective use of nonerodible layers for improving navigability.” Proc., River Flow 2006, R. M. L. Ferreira, E. C. T. L. Alves, J. G. A. B. Leal, and A. H. Cardoso, eds., Taylor and Francis Group, London, Vol. II, 1211–1220.
Struiksma, N. (1985). “Prediction of 2-D bed topography in rivers.” J. Hydraul. Eng., 111(8), 1169–1182.
Thomson, W. (1876). “On the origin of windings of rivers in alluvial plains, with remarks on the flow of water round bends in pipes.” Proc. R. Soc. London, 25, 5–8.
Whiting, P. J., and Dietrich, W. E. (1993). “Experimental studies of bed topography and flow patterns in large-amplitude meanders. I: Observations.” Water Resour. Res., 29(11), 3605–3614.
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Published In
Journal of Hydraulic Engineering
Volume 134 • Issue 2 • February 2008
Pages: 184 - 195
Copyright
© 2008 ASCE.
History
Received: Aug 8, 2006
Accepted: Jun 1, 2007
Published online: Feb 1, 2008
Published in print: Feb 2008
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