摘要
基于不可压缩N-S方程和离散相模型(Discrete Phase Model,DPM),用数值方法研究了粒径为10μm、50μm、100μm、150μm的铀尾矿库滩面颗粒在0.5m/s、1 m/s、2m/s和4m/s风速下的运动轨迹和沉降规律。结果表明,颗粒的运动轨迹同时受到风速和粒径的影响,不同粒径的颗粒在不同风速下运动轨迹相差较大,粒径为10μm的颗粒比粒径为150μm的颗粒在尾矿库下风向的运动随机性要大得多。在同样的大气迁移距离内,0.5 m/s风速下10μm粒径的颗粒所花的时间是4m/s风速的12倍。在相同的风速下,10μm粒径颗粒的迁移距离要远大于150μm粒径颗粒的迁移距离,且150μm粒径颗粒大部分在尾矿库下风向800m内沉积。
Based on the incompressible Navier-Stokes equation and discrete phase model （DPM）, the present paper is engaged in pursu- ing the particle-migrating trajectory and settlement regularity of the pond-side particles at uranium tailing ponds. According to our test, the downward wind direction the size of the tailing pond is about 500 m ×500 m, while the beach surface is 400 m × 400 m at a height of 30 m. The DPM we have adopted is a discrete random model usually used for exploring the effect of the particle size and wind velocity on the particle trajectory. The sizes of the said particles are about 10 μm, 50μm, 100μm, 150 μm under the different wind velocities of about 0.5 m/s, 1 m/s, 2 m/s, and 4 m/s in our numerical simula- tion. The results of our test show that the movement condition of par- ticles seems quite complicated and sometimes irregular in the down- ward wind direction of the tailings pond while the wind velocities and the particle sizes prove to have a certain influence on the trajectory of the particles. Usually, the trajectory of the particles of different sizes under different wind velocities tends to be quite different when the randomness of 10μm particles at the downwind direction of the tailing pond proves stronger than that of 150μm particles. More specifically speaking, the granular migration distance under the smaller wind ve- locity proves much smaller than that under the strong wind with other indexes being equal. Wind velocity is the important factors of parti- cles which depart from beach face of uranium tailing pond. Under the same migration distance, the length of time the 10 150 μm particles of 0.5 m/s wind velocity experience would be 12 times of 4 m/s. And, therefore, the smaller wind velocity is beneficial for the parti- cles to settle down. In addition, the migration distance of 10 μm par- ticles is far greater than that of 150 μm particles under the same wind velocity, though most of the smaller particles may travel the whole flying field, the escaping from the export. And, finally, the migra- tion distance of 150 μm particles proves shorter, most of which may be deposited within 800 m in the downwind direction of the tailings pond.
出处
《安全与环境学报》
CAS
CSCD
北大核心
2013年第1期96-101,共6页
Journal of Safety and Environment
基金
国家自然科学基金项目(11075072)
关键词
环境工程学
铀尾矿库
DPM
数值模拟
运动轨迹
大气迁移
environmental engineering
uranium tailings pond
DPM
numerical simulation
motion trail
aerial migration
