摘要
为了研究不同混合强化方式对微混合的影响,采用有限元法对T型微混合器内增加壁面非均匀Zeta电势的主动式混合以及嵌入肋板的被动式混合进行了数值模拟.对比分析了3种T型微混合器内流场、速度场和浓度场的分布,并研究了不同T型微混合器内溶液混合效率与Re和Sc之间的关系.研究结果表明,两种溶液的混合效率随着Re和Sc的增加非线性减小,且减小趋势变缓;嵌入肋板的被动式T型微混合器内的混合效率沿水平微通道方向上存在较大的波动;增加壁面非均匀Zeta电势的主动式T型微混合器内的混合效率沿水平微通道方向上的波动较小,且这种波动在高Re或低Sc时会被抑制.Re对混合方式的强化效果也有很大的影响.当Re较小时,增加壁面非均匀Zeta电势的主动式混合能更好地提高溶液的混合效率,但当Re较大时,嵌入肋板的被动式混合的混合效果更好.
To study the effects of different mixing enhancement modes on micromixing,numerical simulations with the finite element method were carried out on the simple T-shaped micromixers,the active T-shaped micromixers with surface heterogeneous Zeta potential and the passive T-shaped micromixers with embedded ribs.The flow fields,velocity fields and concentration fields in the 3 kinds of T-shaped micromixers,as well as the relationships between the mixing efficiency and 2 dimensionless parameters Re and Sc,were investigated.The results show that the mixing efficiency decreases with Sc and Re,fast at first and then slowly.The mixing efficiency in the passive T-shaped micromixer with embedded ribs has large undulation along the microchannel,while that in the active T-shaped micromixer with surface heterogeneous Zeta potential has only gentle undulation,and this undulation will be restrained in the cases of high Re values or low Sc values.The Re value also notably influences the improving effect of different mixing enhancement modes.For relatively lower Re values,the outlet mixing efficiency is improved more evidently in the active mixing enhancement mode with surface heterogeneous Zeta potential;otherwise,for relatively higher Re values,that happens instead in the passive mixing enhancement mode with embedded ribs.
出处
《应用数学和力学》
CSCD
北大核心
2016年第3期301-310,共10页
Applied Mathematics and Mechanics
基金
国家自然科学基金(11302095)~~
关键词
T型微混合器
混合强化
电渗流
混合效率
T-shaped micromixer
mixing enhancement
electroosmotic flow
mixing efficiency
