TITLE:
Theory on Orthokinetic Flocculation of Cohesive Sediment: A Review
AUTHORS:
Zhongfan Zhu
KEYWORDS:
Sediment, Orthokinetic Flocculation, Review
JOURNAL NAME:
Journal of Geoscience and Environment Protection,
Vol.2 No.5,
December
18,
2014
ABSTRACT: Investigation on flocculation phenomenon of
cohesive fine-grained sediment has been a important part of sediment dynamics.
During all of three dynamical factors (i.e., Brownian motion, flow shear and
differential settling) that have been verified to play important roles in
promoting flocculation of cohesive sediment, the influence of flow shear on
sediment flocculation has been paid great attention by many researchers (this
flocculation pattern has been termed as “orthokinetic flocculation” in most of
published literatures). Among many researches regarding orthokinetic flocculation,
the dynamical equation developed by Smoluchowski in 1917 (we called it as Smoluchowski
equation hereafter) has been widely adopted as an origin and basement for
theoretically analyzing sediment flocculation under a shear flow. Meanwhile,
many researchers have also pointed out the deficiencies of Smoluchowski
equation (this is because the derivation of Smoluchowski equation was based on
six different assumptions), and correspondingly have amended this equation from
different aspects. In this paper, we attempt to summarize these results,
hopefully providing the theoretical research of sediment orthokinetic
flocculation with some references.