基于复合滑移的微纳缝隙剪切流研究  

Investigation into Shear Flow in Micro/Nano Gap Based on Complicated Boundary Slip

作　　者：陈晖[1] 沈明[2] 

机构地区：[1]福州大学机械工程及自动化学院,福建福州350108 [2]福州大学数学与计算机科学学院,福建福州350108

出　　处：《华南理工大学学报（自然科学版）》2014年第7期68-73,共6页Journal of South China University of Technology(Natural Science Edition)

基　　金：国家自然科学基金资助项目(51305080);福建省自然科学基金资助项目(2012J05089)

摘　　要：边界滑移是微流动的关键特征之一,通过改变流道壁面的滑移状态,为微流动控制提供了新的途径.基于微缝隙下的近壁面滑移效应,结合Navier滑移边界条件,建立亲疏液复合壁面下二维微缝隙剪切流的精确解模型.采用计算流体动力学方法进行微流动建模仿真以验证该数学模型的可靠性,在此基础上结合文献中试验测量所得的滑移参数值,针对壁面滑移状态不同的微缝隙,利用该数学模型研究其内部的微流动规律.结果显示:伴随着壁面运动的微缝隙滑移流场迅速变化,在毫秒级甚至更短时间内趋向于稳定状态.疏液型壁面的运动状态对滑移流动影响小,亲液型壁面的静止状态比运动状态对液体具有更强的束缚能力;在纳米级缝隙中,超亲液静止壁面和超疏液运动壁面结合时,液体将被强力地吸附在亲液壁面上.Boundary slip is one of the key features of micro-flow, and it provides a new way for flow control by changing the slip status of flow channel .Based on the slip effect adjacent to the wall in the micro-gap and the Navier slip boundary condition , a model of exact solution to the shear flow in the two-dimensional micro-gap with a lyophilic and lyophobic wall is constructed .Then, the reliability of the proposed mathematical model is verified by establi-shing a simulation model of micro-flow based on the computational fluid dynamics method , and it is used to investi-gate the micro-flow laws in the micro-gaps with different slip properties according to the slip parameters obtained from the experimental results in relevant literatures .The results show that （1） the slip flow in the micro-gap varies rapidly with the wall movement , and it tends to be steady within milliseconds or below;（2） the lyophilic stationary wall is of a stronger adsorption ability to liquid in comparison with the moving one , while the motion status of the lyophobic wall has a small impact on the slip flow; and （ 3 ） in nano-scale gaps , the integration of the super-lyophilic stationary wall with the super-lyophobic moving wall causes a strong adsorption of liquid on the lyophilic wall to occur .

关 键 词：微纳缝隙 剪切流 复合滑移 非定常流动 

分 类 号：TH137[机械工程—机械制造及自动化]