Criteria for Distinguishing Floc Sedimentation and Gel-Like Network Sedimentation of Cohesive Fine-Grained Sediment in a Turbulent Flow

摘要

The study on the criteria used to distinguishfloc sedimentation and gel-like network sedimentation of cohesive fine-grained sedimentin a turbulent flow has rarely been carried out. In this preliminary study, we derivethree criteria to distinguish these two different sedimentation phases by consideringthe comparison of the time that a characteristic floc takes to settle through meandistance between characteristic flocs and the time that it takes to move throughthe same distance under the influence of a turbulent flow. These criteria incorporatephysical and chemical factors that have been verified to have some influences onthe sediment flocculation in some published literatures, and a simple analysis resultis found to be consistent with our qualitative understandings of flocculation phenomenonof cohesive fine-grained sediment.