Gravity Current of Fluid Mud on Sloping Bed
Publication: Journal of Hydraulic Engineering
Volume 122, Issue 12
Abstract
The presence of fluid mud on inclined beds can cause high transport rates because of sliding due to the gravity force. In the present paper, gravity currents of fluid mud on sloping beds have been studied experimentally; velocity and concentration profiles were measured at two positions in a laboratory flume. The model fluid mud was prepared by suspending china clay in tap water; bulk densities varied from 1,050 to 1,230 kg/m 3. When the apparent viscosity of fluid mud increased markedly with sediment concentration, both turbulent and laminar flows occurred. The observed transition between these flow regimes is in agreement with a transition criterion based on the Bingham plastic rheological model, known from the literature. From the measured profiles, entrainment rates for turbulence flow and bottom shear stresses were calculated. Although entrainment rates show scatter, they are in fair agreement with other empirical data and from an entrainment model adopted in the literature. Experimental bottom friction factors for laminar flow are in agreement with values calculated using the Bingham plastic model. For turbulent flow, the friction factor seems to approach a constant value of about 3⋅10 −3.
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References
1.
Akiyama, J., and Stefan, H.(1985). “Turbidity current with erosion and deposition.”J. Hydr. Engrg., ASCE, 111(12), 1473–1496.
2.
Ali, K. H. M., and Georgiadis, K.(1991). “Laminar motion of fluid mud.”Proc., Inst. Civ. Engrg., Institute of Civil Engineers, London, England, 2, 795–821.
3.
Altinakar, S., Graf, W. H., and Hopfinger, E. J.(1990). “Weakly depositing turbidity current on a small slope.”J. Hydr. Res., Delft, The Netherlands, 28(1), 55–80.
4.
Altinakar, M. S., Graf, W. H., and Hopfinger, E. J. (1993). “Water and sediment entrainment in weakly depositing turbidity currents on small slopes.”Proc., XXV Congr. Int. Assn. Hydr. Res., IAHR, Tokyo, Japan, III, 141–149.
5.
Brørs, B. (1991). “Turbidity current modelling,” PhD thesis 38, Norges Tekniske Høgskole, Troundheim, Norway.
6.
Christodoulou, G. C.(1986). “Interfacial mixing in stratified flows.”J. Hydr. Res., Delft, The Netherlands, 24(2), 77–92.
7.
Coussot, P.(1994). “Steady, laminar, flow of concentrated mud suspensions in open channel.”J. Hydr. Res., Delft, The Netherlands, 32(4), 535–559.
8.
Crapper, M., and Ali, K. H. M. (1996). “A laboratory study of cohesive sediment transport.”4th Nearshore and Estuarine Cohesive Sediment Transport Conf. INTERCOH '94, John Wiley and Sons, Inc., Chichester, England.
9.
De Wit, P. J. (1992a). “Instruments used in the research on cohesive sediments.”Rep. No. 8-92, Dept. Civ. Engrg., Delft Univ. of Technol., Delft, The Netherlands.
10.
De Wit, P. J. (1992b). “Rheological measurements on artificial muds.”Rep. No. 9-92, Dept. Civ. Engrg., Delft Univ. of Technol., Delft, The Netherlands.
11.
Edwards, D. A. (1993). “Turbidity currents: dynamics, deposits and reversals.”Lecture notes in Earth sciences, 44, Springer-Verlag, Berlin, Germany.
12.
Ellison, T. H., and Turner, J. S.(1959). “Turbulent entrainment in stratified flows.”J. Fluid Mech., Cambridge, England, 6, 423–448.
13.
Fernando, H. J. S.(1991). “Turbulent mixing in stratified fluids.”Annu. Rev. Fluid Mech., 23, 455–493.
14.
Hanks, R. W.(1963). “The laminar-turbulent transition for fluids with a yield stress.”A.I.Ch.E. J., 9(3), 306–309.
15.
James, A. E., Williams, D. J. A., and Williams, P. R.(1987). “Direct measurement of static yield properties of cohesive suspensions.”Rheologica Acta, Darmstadt, Germany, 26, 437–446.
16.
Kusuda, T., Watanabe, R., Futawatari, T., and Yamanishi, H. (1993). “Fluid mud movement on an inclined bed.”Coastal and estuarine studies 42. Nearshore and estuarine cohesive sediment transport, A. J. Mehta, ed., American Geophysical Union, Washington, D.C., 281–294.
17.
Kusuda, T., Watanabe, R., and Yamanishi, H. (1996). “Mass fluxes in fluid mud layers on an inclined bed.”4th Nearshore and Estuarine Cohesive Sediment Transport Conf. INTERCOH '94, John Wiley and Sons, Inc., Chichester, England.
18.
Lindenberg, J., Van Rijn, L. C., and Winterwerp, J. C. (1989). “Some experiments on the wave-induced liquefaction of cohesive soils.”J. Coast Res., SI 5, 127–137.
19.
Liu, K. F., and Mei, C. C. (1990). “Approximate equations for the slow spreading of a thin sheet of Bingham plastic fluid.”Phys. Fluids, A2(1), 30–36.
20.
Mehta, A. J., Hayter, E. J., Parker, W. R., Krone, R. B., and Teeter, A. M.(1989a). “Cohesive sediment transport. I: Process description.”J. Hydr. Engrg., ASCE, 115(8), 1076–1093.
21.
Mehta, A. J.(1989b). “Cohesive sediment transport. II: Application.”J. Hydr. Engrg., ASCE, 115(8), 1094–1112.
22.
Middleton, G. V.(1993). “Sediment deposition from turbidity currents.”Annu. Rev. Earth Planetary Sci., 21, 89–114.
23.
Nguyen, Q. D., and Boger, D. V.(1992). “Measuring the flow properties of yield stress fluids.”Annu. Rev. Fluid Mech., 24, 47–88.
24.
Parker, G., Garcia, M., Fukushima, Y., and Yu, W.(1987). “Experiments on turbidity currents over an erodible bed.”J. Hydr. Res., Delft, The Netherlands, 25(1), 123–147.
25.
Teisson, C., Simonin, O., and Galland, J.-C. (1992). “Turbulence and mud sedimentation: a Reynolds stress model and a two-phase flow model.”Proc., 23rd ICCE, Technoprint, Venice, Italy, 2853–5866.
26.
UHCM manual. (1993). Delft Hydraulics, Delft, The Netherlands (in Dutch).
27.
Verreet, G., and Berlamont, H. (1988). “Rheology and non-Newtonian behavior of sea and estuarine mud.”Encyclopedia of fluid mechanics, VII, N. P. Cheremisinoff, ed., Gulf Publications, Houston, Tex.
28.
Wan, Z. (1982). “Bed material movement in hyperconcentrated flow.”Ser. Paper, 31, Inst. of Hydrodynamics and Hydr. Engrg., Tech. Univ. of Denmark, Lyngby, Denmark, 16–24.
Information & Authors
Information
Published In
Journal of Hydraulic Engineering
Volume 122 • Issue 12 • December 1996
Pages: 710 - 717
Copyright
Copyright © 1996 American Society of Civil Engineers.
History
Published online: Dec 1, 1996
Published in print: Dec 1996
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