内置阻块型微混合器内流体混合强化的数值模拟  

Numerical simulation of fluid mixing reinforcement in micro-mixers with barriers embedded

作　　者：王昆[1] 王嘉骏[1] 冯连芳[1] 顾雪萍[1] 

机构地区：[1]浙江大学化学工程与生物工程学系化学工程联合国家重点实验室,浙江杭州310027

出　　处：《化学工程》2010年第12期30-34,共5页Chemical Engineering(China)

基　　金：浙江省自然科学基金资助项目(Y4090319)

摘　　要：采用计算流体力学方法对3种内置阻块波浪形微混合器进行模拟研究,考察内置阻块尺寸、排列方式及阻块数量对流体混合的强化效果。由速度场和物质输运模型结合进行流体的混合模拟,得到流体混合快照图和流体混合速率,进一步由流体平均径向线拉伸和李雅普洛夫指数定量表征混沌混合程度。结果表明:混合器壁面波浪状V形凹槽的设计和微通道内长方块的设置产生周期性的流场,从而引发混沌流。将阻块倾斜设置或增加微通道内阻块的数量,混沌流作用增强,从而促进流体混合。最后考察了不同贝克来数Pe下流体的混合性能,发现微通道混合量纲一长度与lnPe之间呈线性关系。The effects of the geometry,arrangement and number of embedded rectangular barriers on the mixing performance for three types of wavy micro-channels were investigated by computational fluid dynamics（CFD） method.The mass transportation model based on the flow field was applied to simulate the mixing process,in terms of mixing snapshots and fluids mixing rate.The averaged fluid line stretching and Lyapunov exponent were used to characterize the chaotic behavior,which was induced by the periodic velocity field in the micro-channels,due to the V-shaped grooves and barriers.By setting the barriers slantwise or changing its geometry and number,chaos was further enhanced,reinforcing the fluids mixing more effectively.The mixing performance of each mixer by different Peclet number Pe was studied,and the dimension-one mixing length was found to grow linearly with ln Pe.

关 键 词：微混合器 混沌混合 计算流体力学 线拉伸 李雅普洛夫指数 

分 类 号：O35[理学—流体力学]