考虑电离作用的淤泥异向絮凝三维数值模拟

鉴于试验观察淤泥絮凝结构的技术难度,本文尝试以布朗动力学为基础,采用蒙特卡洛方法动态模拟电离作用下颗粒成长为絮团的过程.为结合实际情况,泥沙颗粒初始位置由颗粒粒径和淤泥密度决定,颗粒初始速度按照相应条件下高斯随机分布给定.边界条件用和实际符合较好的循环边界.在模拟数据分析的基础上,讨论并比较了颗粒粒径和淤泥密度对絮凝时间以及絮团开放程度的影响.另一方面,讨论了电离作用后颗粒电荷量对絮团生长的影响.解释了泥沙颗粒表面电荷密度变化对絮凝过程和絮团结构的影响,模拟结果和实际情况较为一致.

Brownian Dynamic Simulation of Sludge Perikinetic Flocculation with Ionization

A Brownian dynamic simulation of perikinetic flocculation of fine sediment with ionization is presented.Langevin equation is used as dynamical equation in tracking particles in a floc.Monte Carlo method is used in simulating random variation in particle movement.Sludge particles are supposed in uncharged and charged state in dispersion system.Electrostatic force on a particle in a simulation cell is considered as a sum of electrostatic force from other particles in the original cell.Particle initial place is decided by particle diameter and sludge density.Particle initial velocity is determined by Gauss random distribution.Effects of particle diameter and sludge density on flocculation and floc structure are discussed.On the other hand,effects of electrostatic force on flocculation are presented.The model proposed coincide well with practical situations.