毛细管单相分离流中溶质Taylor分散的数值模拟  

Numerical simulations of solute Taylor dispersion of separated flows in capillaries

作　　者：李响[1] 刘辉[1] 

机构地区：[1]北京化工大学化工资源有效利用国家重点实验室,北京100029

出　　处：《北京化工大学学报（自然科学版）》2009年第B11期8-13,共6页Journal of Beijing University of Chemical Technology(Natural Science Edition)

基　　金：国家"973"计划(2006CB202503);教育部博士点基金(2006001005)

摘　　要：采用计算流体力学(CFD)和轴向扩散模型方法研究圆形毛细管内单相分离流中溶质的Taylor分散问题。模拟计算绕Taylor气泡状障碍物所形成分离流中溶质的轴向扩散系数,分别考察了液体速度、单元胞长度、液膜厚度、液膜长度、毛细管管径以及单元胞数对轴向扩散系数的影响。结果表明,雷诺数介于750～1950的情况下,轴向扩散系数随入口液速、液栓长度以及单元胞数的增大而增大;管径介于2～5 mm之间时,轴向扩散系数随着管径的增大而增大;管径大于5 mm时,轴向扩散系数的增速缓慢;液膜厚度及液膜长度的改变对轴向扩散系数影响不大。Computational fluid dynamics （CFD） numerical simulations were carried out to compute the axial diffusion coefficient （Dz） of the solute Taylor dispersion in single-phase separated flows in capillaries. The effects of the liquid velocity, unit cell length, film thickness, film length, the diameter of capillary, and the number of unit cell were investigated. The results of simulation indicate that under the condition of Re between 750 and 1950 the Dz values is increasing with increasing values of liquid velocity, unit cell length and the number of unit cells. When the diameter of capillary between 2 and 5 mm, the Dz values is increasing with increasing values of the diameter; when the diameter of capillary large than 5 mm, the increasing current of Dz become slowness. The Dz values is independent of film thickness and film length.

关 键 词：毛细管 计算流体力学模拟 Taylor气泡 轴向扩散系数 

分 类 号：TQ021.1[化学工程]