水利学报2012，Vol.43Issue(10)：1194-1201,8.
均匀切变水流对黏性细颗粒泥沙絮凝的影响研究
The effect of uniform shear flow on flocculation of cohesive fine sediment
摘要
Abstract
Flocculation of cohesive fine sediment is an important research subject in river dynamics but not perfect.Based on fractal cluster growing theory,the effect of uniform shear flow on the flocculation of cohesive fine sediment was studied through simulating the process of collision and bonding of particles and clusters under the effect of brown motion,gravity settling and uniform shear flow in MATLAB using 3-D off-lattice algorithm,considering the breakage of flocs as well as the effect of sediment concentration on viscosity of suspension.The results reveal that flow force can promote the flocculation of cohesive fine sediment by improving the collision probability of particles,while the breakage of flocs becomes significant under high flow shear force,so the velocity gradient affects the flocculation process to a certain extent,that is,the flocculation rate and the average diameter of flocs appear the trend from increasing to decreasing as the velocity gradient increased;the size distribution of flocs becomes more uniform,flocs have a better development in the vertical direction of flow and fractal dimension of flocs is high under the action of uniform shear flow.It is a successful attempt for further study of flocculation mechanism of cohesive fine sediment in natural river.关键词
黏性细颗粒泥沙/均匀切变水流/三维模拟/速度梯度/分形维数Key words
cohesive fine sediment/uniform shear flow/3-D simulation/velocity gradient/fractal dimension分类
建筑与水利引用本文复制引用
柴朝晖,杨国录,陈萌,余明辉..均匀切变水流对黏性细颗粒泥沙絮凝的影响研究[J].水利学报,2012,43(10):1194-1201,8.基金项目
国家重点基础科学研究（973）计划资助项目 （）
国家自然科学基金项目 （）
中央高校基本科研业务费专项资金资助 （）
