Sediment Evacuation from Reservoirs through Intakes by Jet-Induced Flow
Publication: Journal of Hydraulic Engineering
Volume 141, Issue 2
Abstract
Reservoir sedimentation is considered as a sustainability problem. A concept getting down to the root of the cause was developed and tested in laboratory experiments. The idea is to maintain sediment in suspension, i.e., avoiding its settling near the dam by generating a jet induced artificial flow field and related turbulence (rotational flow), enabling the release of suspended sediment through the power intake. Therefore, a perpendicular jet configuration consisting of four jets arranged in a horizontal plane was investigated in a rectangular basin equipped with an outlet structure. The influence of its geometric parameters and the jet discharge on the sediment release was analyzed in detail. The flow pattern and its effect on the sediment release efficiency were evaluated, by measurements of turbidity and flow velocity. Depending on experiment duration and discharge, an ideal parameter set was identified resulting in a release efficiency between 1.5 and 2 compared to the reference case without jets.
Get full access to this article
View all available purchase options and get full access to this article.
Acknowledgments
The research reported in this paper was supported by Swisselectric Research. Thanks are also expressed to Johannes Bühler, who passed away in 2012, for continuous support and invaluable comments.
References
Armenante, P. M., and Nagamine, E. U. (1998). “Effect of low off-bottom impeller clearance on the minimum agitation speed for complete suspension of solids in stirred tanks.” Chem. Eng. Sci., 53(9), 1757–1775.
Basson, G. R. (2010). ICOLD bulletin 147: Sedimentation and sustainable use of reservoirs and river systems, International Commission on Large Dams (ICOLD) Sedimentation Committee.
Buckingham, E. (1915). “Model experiments and the forms of empirical equations.” Trans. ASME, 37, 263–296.
Busnaina, A. A., Lilley, D. G., and Moretti, P. M. (1981). “Prediction of local destratification of lakes.” J. Hydraul. Div., 107(HY3), 259–272.
De Cesare, G., Schleiss, A., and Hermann, F. (2001). “Impact of turbidity currents on reservoir sedimentation.” J. Hydraul. Eng., 6–16.
Fanneløp, T. K., Hirschberg, S., and Küffer, J. (1991). “Surface current and recirculating cells generated by bubble curtains and jets.” J. Fluid Mech., 229, 629–657.
Fossett, H., and Prosser, L. E. (1949). “The application of free jets to the mixing of fluids in bulk.” Proc. Mech. Eng., 160(1), 224–232.
Fox, E. A., and Gex, V. E. (1956). “Single-phase blending of fluids.” AIChE J., 2(4), 539–544.
Goossens, L. H. J. (1979). “Reservoir destratification with bubble columns.” Ph.D. thesis, Delft University Press, Delft, Netherlands.
Graf, W. H. (1984). “Storage losses in reservoirs.” Int. Water Power Dams Constr., 36(4), 37–40.
Grenville, R., and Tilton, J. N. (1996). “Turbulence of flow as a predictor of blend time in turbulent jet mixed vessels.” Proc., European Conf. on Mixing, J. Bertrand and J. Villermaux, eds., Paris, France, 67–74.
Jayanti, S. (2001). “Hydrodynamics of jet mixing in vessels.” Chem. Eng. Sci., 56(1), 193–210.
Jenzer Althaus, J. M. I. (2011). “Sediment evacuation from reservoirs through intakes by jet induced flow.” Ph.D. thesis, Laboratory of Hydraulic Constructions, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.
Jenzer Althaus, J. M. I., De Cesare, G., and Schleiss, A. (2010). “Experiments on water jet induced cyclonic circulation—Measurement of flow pattern and sediment concentration at reservoir outlet works.” Proc., ISUD 7, J. Johan Wiklund, E. Levenstam Bragd, and S. Manneville, eds., Chalmers Univ., Gothenburg, Sweden, 39–42.
Jirka, G., and Harleman, D. R. F. (1979). “Stability and mixing of a vertical plane jet in confined depths.” J. Fluid Mech., 94(2), 275–304.
Kantoush, S. A., Schleiss, A., and Nagy, H. (2009). “Deposition of sediment mixture due to jet effluent into a rectangular shallow reservoir.” Alexandria Eng. J., 47(5), 451–462.
Kundu, P. K., and Cohen, I. M. (2008). Fluid mechanics, 4th Ed., Elsevier, Boston.
Lane, A. C. G., and Rice, P. (1982). “An investigation of liquid jet mixing employing an inclined side entry jet.” Trans. Inst. Chem. Eng., 60, 171–176.
Maruyama, T., Ban, Y., and Mizushina, T. (1982). “Jet mixing of fluids in tanks.” J. Chem. Eng. Jpn., 17(2), 120–126.
Maruyama, T., Kamishima, N., and Mizushina, T. (1984). “An investigation of bubble plume mixing by comparison with liquid jet mixing.” J. Chem. Eng. Jpn, 17(2), 121–126.
Mobley, M., Tyson, W., Webb, J., and Brook, G. (1995). “Surface water pumps to improve dissolved oxygen content of hydropower releases.” Proc., WaterPower, Vol. 1, ASCE, Reston, VA, 20–29.
Morillo, S., Imberger, J., Antenucci, J. P., and Copetti, D. (2009). “Using impellers to distribute local nutrient loadings in a stratified lake: Lake Como, Italy.” J. Hydraul. Eng., 564–574.
Oehy, C., De Cesare, G., and Schleiss, A. (2010). “Effect of inclined jet screen on turbidity current.” J. Hydraul. Res., 48(1), 81–90.
Oehy, C., and Schleiss, A. (2007). “Control of turbidity currents in reservoirs by solid and permeable obstacles.” J. Hydraul. Eng., 637–648.
Okita, N., and Oyama, Y. (1963). “Mixing characteristics of jet mixing.” Kagaku Kogaku, 27(4), 252–260.
Patwardhan, A. W., and Gaikwad, S. G. (2003). “Mixing in tanks agitated by jets.” Chem. Eng. Res. Des., 81(2), 211–220.
Perona, J. J., Hylton, T. D., Youngblood, E. L., and Cummins, R. L. (1998). “Jet mixing of liquids in long horizontal cylindrical tanks.” Ind. Eng. Chem. Res., 37(4), 1478–1482.
Ranade, V. V. (1996). “Towards better mixing protocols by designing spatially periodic flows: The case of a jet mixer.” Chem. Eng. Sci., 51(11), 2637–2642.
Revill, B. K. (1992). “Jet mixing.” Mixing in process industries, J. Harnby, N. F. Edwards, and A. W. Nienow, eds., Butterworth-Heinemann, Oxford, U.K., 159–183.
Ricou, F. P., and Spalding, D. B. (1961). “Measurements of entrainment by axisymmetrical turbulent jets.” J. Fluid Mech., 11(1), 21–32.
Riess, I. R., and Fanneløp, T. K. (1998). “Recirculating flow generated by line-source bubble plumes.” J. Hydraul. Eng., 932–940.
Robinson, K. M., Garton, J. E., and Punnett, R. E. (1982). “Localized destratification at Lake Texoma.” J. Environ. Eng. Div., 108(4), 739–749.
Scheidegger, A., Stöckli, A., and Wüest, A. (1994). “Influence of the internal restoration measures on the oxygen balance in Lake Hallwil.” Wasser, Energie, Luft–Eau, énergie, air, (5–6), 126–131.
Schleiss, A., De Cesare, G., and Jenzer Althaus, J. M. I. (2010). “Reservoir sedimentation threatens the sustainable use of hydropower.” Wasser, Energie, Luft–Eau, énergie, air, 102(1), 31–40.
Sharma, R. N., and Shaikh, A. A. (2003). “Solids suspension in stirred tanks with pitched blade turbines.” Chem. Eng. Sci., 58(10), 2123–2140.
Sherman, B. (2000). “Scoping options for mitigating cold water discharges from dams.”, CSIRO Land and Water, Canberra, Australia.
Stephens, R., and Imberger, J. (1993). “Reservoir destratification via mechanical mixers.” J. Hydraul. Eng., 438–457.
Wasewar, K. L. (2006). “A design of jet mixed tank.” Chem. Biochem. Eng. Q., 20(1), 31–46.
Wüest, A., Brooks, N. H., and Imboden, D. M. (1992). “Bubble plume modeling for lake restoration.” Water Resour. Res., 28(12), 3235–3250.
Yalin, M. S. (1971). Theory of hydraulic models, Vol. 266, Macmillan, London.
Zughbi, H. D. (2006). “Numerical simulation of mixing in a jet agitated horizontal cylindrical tank.” Int. J. Comput. Fluid Dyn., 20(2), 127–136.
Zughbi, H. D., and Rakib, M. A. (2004). “Mixing in a fluid jet agitated tank: Effect of jet angle and elevation and number of jets.” Chem. Eng. Sci., 59(4), 829–842.
Zwietering, T. N. (1958). “Suspending of solid particles in liquid by agitators.” Chem. Eng. Sci., 8(3–4), 244–253.
Information & Authors
Information
Published In
Journal of Hydraulic Engineering
Volume 141 • Issue 2 • February 2015
Copyright
© 2014 American Society of Civil Engineers.
History
Received: Jan 6, 2014
Accepted: Oct 8, 2014
Published online: Nov 10, 2014
Published in print: Feb 1, 2015
Discussion open until: Apr 10, 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.