微纳通道中牛顿流体毛细流动的研究进展

发布时间：2018-08-01 13:07

【摘要】：毛细流动广泛存在于自然科学与工程技术等诸多领域,微纳通道中毛细流动近年来在微纳机电系统、生物医学、环境监测、石油开采、多孔介质渗流等领域获得了广泛应用.描述宏观牛顿流体毛细流动过程的是Lucas-Washburn(LW)模型,该模型在微纳通道中的适用性还没有定论,因而受到国际学术界关注.本文从理论模型、数值模拟和实验研究3个方面综述了微纳通道中牛顿流体毛细流动的研究进展,已有的研究表明需要对毛细流动进行分区讨论:(1)惯性力作用区,流动距离与时间t成正比;(2)黏性力-惯性力作用区,惯性力、毛细力、黏性力均对流动有影响;(3)黏性力作用区,黏性力与毛细力平衡,流动距离与t~(1/2)成正比;(4)竖直管道中还需要考虑重力的影响,存在黏性力-重力作用区.在黏性力作用区,LW模型仍然可以定性描述微纳通道中毛细流动过程,但需要引入动态接触角、气泡、电黏性等影响因素的修正.最后针对目前实验研究中存在的一些问题,总结有待深入研究的方向.另外,本文也对非牛顿流体毛细流动的研究做了简单介绍和展望.
[Abstract]:Capillary flow has been widely used in many fields, such as natural science and engineering technology. In recent years, capillary flow in micro-nano channels has been widely used in micro / nano electromechanical systems, biomedicine, environmental monitoring, petroleum exploitation, porous media seepage and so on. The Lucas-Washburn (LW) model is used to describe the capillary flow process of macroscopic Newtonian fluids. The applicability of the model in micro and nano channels is still uncertain, so it has attracted much attention from the international academic circles. In this paper, the research progress of capillary flow of Newtonian fluid in micro and nano channels is reviewed from three aspects: (1) inertial force region. The flow distance is proportional to the time t; (2) the viscous force-inertial force zone, the inertial force, the capillary force, and the viscous force all have an effect on the flow; (3) the viscous force zone, the viscous force and the capillary force balance, The flow distance is proportional to t ~ (1 / 2). (4) the influence of gravity should be taken into account in vertical pipeline. The LW model can still be used to describe the capillary flow process in micro and nano channels qualitatively, but it is necessary to introduce the correction of dynamic contact angle, bubble, electric viscosity and so on. Finally, in view of some problems existing in the current experimental research, the direction of further research is summarized. In addition, the study of capillary flow of non-Newtonian fluids is also briefly introduced and prospected.
【作者单位】：清华大学工程力学系热科学与动力工程教育部重点实验室;
【基金】：国家自然科学基金(51322603,51136001,51356001,51321002) 教育部新世纪优秀人才支持计划资助
【分类号】：O363.2

【相似文献】