波浪形微通道中液体混合特性的数值模拟  

Numerical simulation of liquid mixing characteristics in wavy microchannels

作　　者：周东健 秦利涛 岳金彩[1] 郑世清[1] ZHOU Dong-jian;QIN Li-tao;YUE Jin-cai;ZHENG Shi-qing(Institute of Computer and Chemical Engineering,Qingdao University of Science and Technology,Qingdao 266042,Shandong Province,China)

机构地区：[1]青岛科技大学计算机与化工研究所,山东青岛266042

出　　处：《化学工程》2021年第10期68-73,共6页Chemical Engineering(China)

基　　金：山东省重点研发计划项目资助(2019JMRH00305)。

摘　　要：采用数值模拟方法研究出口尺寸为500μm×500μm的圆和椭圆弧波浪形微通道的混合特性。受离心力影响波浪形通道在较低雷诺数下(Re=10)可产生二次流漩涡,随着雷诺数增大二次流漩涡逐步由两涡结构过渡到四涡及多涡结构,混合强度急剧增加。通过改变圆的曲率R,发现二次流漩涡及混合强度随迪恩数的增大而增强,且在中等雷诺数下(Re≈100)曲率R对混合的影响最为明显;在所考察范围内,曲率半径最小的圆波浪形通道混合效果最好,同时压降也最大。改变椭圆半轴长度比,发现通道压降随着半轴长度比的减小而降低,而混合强度和平均迪恩数则呈现先增大后减小的趋势;当半轴长度比a/b=0.75时,通道的平均迪恩数最大,混合强度最大,而压降相对较低。The mixing characteristics of circular and elliptical wavy microchannels with an outlet size of 500μm×500μm were studied by numerical simulation.Secondary flow can be generated at a low Reynolds number(Re=10)due to the centrifugal force in wavy microchannels.With Reynolds numbers increasing,the secondary flow vortex gradually transits from two-vortex to four-vortex and multi-vortex,and the mixing intensity increases sharply.By changing the curvature,it was found that the mixing intensity and the secondary flow increased with the Dean numbers,and curvatures had the most influence on mixing under medium Reynolds number(Re≈100).In the range of the researched curvature radii,the circular wavy microchannel with the smallest radius had the best mixing intensity,but the required pressure drop also reached a maximum.By changing the half axes ratio,it was found that the channel pressure drop decreased with the decrease of the half axes ratio,while the mixing intensity showed a trend of first increasing and then decreasing.When the half axes ratio a/b=0.75,the average Dean number reached a maximum,meanwhile the mixing intensity was at the best and pressure drop was relatively low.

关 键 词：二次流 波浪形微通道 混合强度 迪恩数 

分 类 号：TQ021.1[化学工程] TQ021.4