Influence of Coherent Flow Structures on the Dynamics of Suspended Sediment Transport in Open-Channel Flow
Publication: Journal of Hydraulic Engineering
Volume 130, Issue 11
Abstract
The influence of suspended sediments on coherent flow structures has been studied by simultaneously measuring the longitudinal and vertical components of the instantaneous velocity vector and the instantaneous suspended particle concentration with an acoustic particle flux profiler. The measurements were carried out in clear water and in particle-laden open-channel flows. In both cases, they clearly show the predominance of ejection and sweep phases that are part of a burst cycle. The analysis further demonstrates the importance of the ejection and sweep phases in sediment resuspension and transport. Ejections pick up the sediment at the bed and carry it up through the water column close to the surface. It is shown that ejections and sweeps are in near equality in the near-bottom layer, whereas ejections clearly dominate in the remaining water column. The implications of these results for sediment transport dynamics are discussed.
Get full access to this article
View all available purchase options and get full access to this article.
References
1.
Cellino, M. ( 1998). “Experimental study of suspension flows in open channels.” Doctoral thesis No. 1824, Ecole Polytechnique Fédérale de Lausanne, Switzerland.
2.
Cellino, M., and Graf, W. H. (1999). “Sediment-laden flow in open channels under noncapacity and capacity conditions.” J. Hydraul. Eng., 125(5), 455–462.
3.
Cellino, M., and Graf, W. H. (2000). “Experimental study of suspension flows in open channels over bed forms.” J. Hydraul. Res., 28, 289–298.
4.
Fortier, A. ( 1967). Mechanique des suspensions, Masson, Paris.
5.
Garcia, M.H., Nino, Y., and Lopez, F. ( 1996). “Laboratory observations of particle entrainment into suspension by turbulent bursting.” Current flow structures in open channels, P. J. Ashworth, S. J. Bennet, J. I. Best, and S. J. McLelland, eds., Wiley, New York, 63–84.
6.
Grass, A. J. (1971). “Structural features of turbulent flow over smooth and rough boundaries.” J. Fluid Mech., 50, 233–255.
7.
Grass, A.J. ( 1983). “The influence of boundary layer turbulence on the mechanics of sediment transport.” Euromech 156: Mechanics of Sediment Transport, Istanbul, 3–17.
8.
Grass, A.J., and Mansour-Tehrani, M. ( 1996). “Generalized scaling of coherent structures in the near-wall region of turbulent flow over smooth and rough boundaries.” Coherent flow structures in open channels, P. J. Ashworth, S. J. Bennet, J. I. Best, and, S. J. McLelland, eds., Wiley, New York, 41–61.
9.
Hinze, O.J. ( 1975). Turbulence, McGraw–Hill, New York.
10.
Hurther, D., and Lemmin, U. (2001). “Discussion of ‘equilibrium near-bed concentration of suspended sediment,’ by Z. Cao.” J. Hydraul. Eng., 127(5), 430–433.
11.
Jackson, R. G. (1976). “Sedimentological and fluid-dynamic implications of the turbulent bursting phenomenon in geophysical flows.” J. Fluid Mech., 77, 531–560.
12.
Lu, S. S., and Willmarth, W. W. (1973). “Measurements of the structure of the Reynolds stress in a turbulent boundary layer.” J. Fluid Mech., 60, 481–511.
13.
Nakagawa, H., and Nezu, I. (1977). “Prediction of the contributions to the Reynolds stress from bursting events in open-channel flows.” J. Fluid Mech., 80, 99–128.
14.
Nakagawa, H., and Nezu, I. (1981). “Structure of space–time correlations of bursting phenomena in an open-channel flow.” J. Fluid Mech., 104, 1–43.
15.
Nelson, J. M., Shreve, R. L., Mclean, S. R., and Drake, T. G. (1995). “Role of near-bed turbulence structure in bed load transport and bed form mechanism.” Water Resour. Res., 31, 2071–2086.
16.
Nezu, I., and Nakagawa, H. ( 1993). “Turbulence in open-channel flows.” IAHR Monograph, Balkema, Rotterdam, the Netherlands.
17.
Rashidi, M., Hetsroni, G., and Banerjee, S. (1990). “Particle-turbulence interaction in a boundary layer.” Int. J. Multiphase Flow, 16, 935–949.
18.
Robinson, S. K. (1991). “Coherent motions in the turbulent boundary layer.” Annu. Rev. Fluid Mech., 23, 601–639.
19.
Rolland, T., and Lemmin, U. (1997). “A two-component acoustic velocity profiler for use in turbulent open-channel flow.” J. Hydraul. Res., 35, 545–561.
20.
Shen, W., and Lemmin, U. (1998). “Improvements in acoustic sediment concentration profiling using a Lms compensation algorithm.” IEEE J. Ocean. Eng., 23, 96–104.
21.
Shen, W., and Lemmin, U. (1999). “Application of an acoustic particle flux profiler in particle-laden open-channel flow,” J. Hydraul. Res., 37, 407–419.
22.
Smith, J. ( 1996). “Coherent flow structures in smooth-wall turbulent boundary layers: Facts, mechanisms, speculations.” P. J. Ashworth, S. J. Bennet, J. I. Best, and S. J. McLelland, eds., Coherent flow structures in open channels, Wiley, New York, 1–38.
23.
Sumer, B. M., and Oguz, B. (1978). “Particle motions near the bottom in turbulent flow in an open channel.” J. Fluid Mech., 86, 109–127.
24.
Sumer, B. M., and Deigaard, R. (1981). “Particle motions near the bottom in turbulent flow in an open channel. Part 2.” J. Fluid Mech., 86, 311–377.
25.
Sutherland, A. J. (1967). “Proposed mechanism for sediment entrainment by turbulent flows.” J. Geophys. Res., 72, 6183–6194.
Information & Authors
Information
Published In
Journal of Hydraulic Engineering
Volume 130 • Issue 11 • November 2004
Pages: 1077 - 1088
Copyright
Copyright © 2004 ASCE.
History
Published online: Oct 15, 2004
Published in print: Nov 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.