黄河泥沙架桥絮凝体分形结构的动态演变研究  

Study on dynamic evolution of fractal structure of bridging flocculated sand aggregates in Yellow River

作　　者：李冬梅[1] 梅胜[2] 谭万春[3] 金同轨[1] 

机构地区：[1]西安建筑科技大学环境与市政工程学院,西安710055 [2]广东工业大学建设学院(五山校区),广州510643 [3]长沙理工大学化学与环境工程系,长沙410076

出　　处：《给水排水》2004年第11期1-5,共5页Water & Wastewater Engineering

基　　金：国家自然科学基金项目 (5 0 0 780 4 3)

摘　　要：黄河泥沙架桥絮凝试验研究表明 ,剪切絮凝条件下泥沙絮凝体的最佳絮凝结构只能维持一段时间。在整个剪切絮凝过程中 ,泥沙絮凝体的分形结构从疏松多孔、开放的分枝状DLCA构造 ,逐步演变到密实的最佳RLCA构造后 ,又开始呈现疏松脆弱结构。絮凝体分维值上升至某一值后 ,又以微小的幅度下降。停止搅拌后 ,泥沙絮凝体粒径能在瞬间长大 ,但絮团结构脆弱稀疏 。Shear-induced sand bridging flocculated settling experiment is conducted for Yellow River and the result indicates that the lifetime of optimal structure will be limited for a certain duration. During the whole shear flocculation stages, the dynamic evolution process of fractal structure of sand aggregates is observed that the fractal structure can change from loose and open-branching DLCA structure to compact RLCA structure little by little. However, the structure begins to become loose as flocculation process continues. The fractal dimension value of aggregates increases to an optimum value gradually and then begins to decrease slowly with small extent. When stirring is stopped, the size of sand aggregates grows immediately and the floc structure becomes weak and thin. As a result, the fractal dimension value of aggregates is low.

关 键 词：絮凝体 絮凝条件 絮凝过程 黄河 泥沙 试验研究 搅拌 密实 凝结 剪切 

分 类 号：TU991[建筑科学—市政工程] X703[环境科学与工程—环境工程]