黏性细颗粒泥沙絮凝及沉降的三维模拟

鉴于试验观察黏性细颗粒泥沙悬浮体系絮凝-沉降过程存在技术困难，尝试以分形生长理论为基础，使用改进的受限反应絮团聚集(RLCCA)模型，在计算机上模拟这一复杂过程。模型考虑了絮团的分形结构与可渗透特性、泥沙浓度对悬浮液黏性的影响等因素，复演颗粒、絮团在重力沉降和布朗作用下的三维运动及相互碰撞并黏结的现象。在对模拟数据的统计分析基础上，讨论了絮凝-沉降过程的各种特性，结果表明：碰撞效率系数不同时，絮凝发育过程存在相似性。

3-D simulation of flocculation-settling of cohesive fine sediment

Since it is difficult to observe the flocculation-settling of cohesive fine sediment this omplicated process is numerically simulated based on fractal growth theory by using an improved Reaction Limited Cluster-Cluster Aggregation (RLCCA) model. Some factors such as the fractal structure and permeability of flocs, effect of sediment concentration on fluid viscosity, etc. are carefully considered. The Brown motion, gravity settling, collision and cohesion of particles and clusters are simulated in the 3-D space. Based on the analysis of statistical data obtained from this numerical calculation experiment the various characteristics of flocculation-settling process are discussed. It is found that a type of similarity exists in the growing process of flocculation-settling in different layers of the suspended system.