The study on the criteria used to distinguish
floc sedimentation and gel-like network sedimentation of cohesive fine-grained sediment
in a turbulent flow has rarely been carried out. In this preliminary study, we derive
three criteria to distinguish these two different sedimentation phases by considering
the comparison of the time that a characteristic floc takes to settle through mean
distance between characteristic flocs and the time that it takes to move through
the same distance under the influence of a turbulent flow. These criteria incorporate
physical and chemical factors that have been verified to have some influences on
the sediment flocculation in some published literatures, and a simple analysis result
is found to be consistent with our qualitative understandings of flocculation phenomenon
of cohesive fine-grained sediment.
References
[1]
Camp, T. R., & Stein, P. C. (1943). Velocity Gradients and Internal Work in Fluid Motion. Journal of Boston Society of Civil Engineering, 30, 219-237.
[2]
Feder, J. (1988). Fractals. New York: Plenum. http://dx.doi.org/10.1007/978-1-4899-2124-6
[3]
Fei, X. (1994). Transport Hydraulics of Slurry and Granular Material. Beijing: Tsinghua University Press. (In Chinese)
[4]
Lu, S., Ding, Y., & Guo, J. (1998). Kinetics of Fine Particle Aggregation in Turbulence. Advances in Colloid and Interface Science, 78, 197-235. http://dx.doi.org/10.1016/S0001-8686(98)00062-1
[5]
Wang, X., Shao, X., & Li, D. (2002). Fundamentals of River Dynamics. Beijing: China Water and Power Press. (In Chinese)
[6]
Yang, T., Xiong X., Zhan X., & Yang, M. (2003). On Flocculation of Cohesive Fine Sediment. Hydro-Science and Engineering, 2, 65-77. (In Chinese)
[7]
Zhu, Z., Yang, T., Zhao, M., & Liang, C. (2009). Preliminary Study on the Critical Criterion for Distinguishing Floc Sedimentation and Gel-Like Network Sedimentation. Journal of Sediment Research, 1, 20-25. (In Chinese)
[8]
Zhu, Z. (2009). The Investigation on Phase Transition and the Influence of Shear on the Flocculation of Cohesive Sediment. M.S. Thesis, Beijing: Tsinghua University. (In Chinese)
