颗粒在脉动气流场中受力和分选的数值模拟  

Numerical simulation of force and separation on particles in pulsing airflow

作　　者：韦鲁滨[1] 李大虎[1] 陈赞歌 孙铭阳[1] 朱学帅[1] 

机构地区：[1]中国矿业大学(北京)化学与环境工程学院,北京100083

出　　处：《中国矿业大学学报》2017年第1期162-168,176,共8页Journal of China University of Mining & Technology

基　　金：国家自然科学基金项目(51574252);国家重点基础研究发展计划(973)项目(2012CB214904);高等学校博士学科点专项科研基金项目(20120023110017)

摘　　要：运用网格模型理论和计算流体力学方法研究了气流脉动频率、脉动速度振幅以及固体体积分数对颗粒绕流阻力系数的影响.结果表明:固体体积分数小于0.1%时,阻力系数与单颗粒无限绕流时基本一致;体积分数大于1%时,阻力系数显著增大;脉动速度振幅增大,阻力系数近似线性增加,而脉动频率对阻力系数影响不大.在此基础上,建立了脉动气流场中颗粒阻力系数的修正关联式.基于湍流模型和离散相模型相耦合的方法,结合阻力系数修正公式与随机轨道模型,数值模拟了变径脉动气流场中6~3mm细粒煤的分选过程,各密度级重产物分配率均方根误差为4.87%.The tion on drag co tational fluid d sistent with th influence of pulsation rate, fluctuating velocity amplitude and solid volume frac- efficient in pulsing airflow was studied using the theory of cell model and compu- ynamics method. The results show that the drag coefficients are basically con- e standard values when the particle volume fraction is below 0. 1%, but increase significantly when the volume fraction is above 1%. Besides, the drag coefficients increase line- arly with the increasing of fluctuating velocity amplitude, but are hardly affected by the pulsa- tion rate. On this basis, the modified formulae in pulsing airflow were established to improve the standard drag coefficient curve. According to the coupling methods of turbulence model and discrete phase model, the separation process of 6-3 mm coal particles in pulsing air classifier was simulated by combining the modified formulae and the stochastic tracking model. As a re- sult, root-mean-square error of partition coefficients of heavy product with different density fractions is 4.87%.

关 键 词：脉动 气流 分选 阻力系数 

分 类 号：TD94[矿业工程—选矿]