流动聚焦及射流不稳定性

发布时间：2018-06-22 01:21

本文选题：流动聚焦 + 射流不稳定性　；参考：《力学进展》2017年00期

【摘要】：流动聚焦是一种有效的微细射流产生方法,其原理可以描述为从毛细管流出的流体由另一种高速运动的流体驱动,经小孔聚焦后形成稳定的锥-射流结构,射流因不稳定性破碎成单分散的液滴.自从1998年流动聚焦被提出以来,陆续发展了单轴流动聚焦、电流动聚焦、复合流动聚焦和微流控流动聚焦等毛细流动技术.这些技术稳定、易操作、没有苛刻的环境条件的要求,能够制备单分散性较好的微纳米量级的液滴、颗粒和胶囊,在科学研究和实际应用中具有重要价值.流动聚焦涉及了多尺度、多界面和多场耦合的复杂流体力学问题,其中稳定的锥形是形成稳定射流的先决条件,过程参数是影响射流界面扰动发展的关键因素,而射流不稳定性分析是揭示射流破碎的最主要理论工具.该文回顾了近二十年来不同结构流动聚焦的研究进展,概述这些技术涉及的过程控制、流动模式、尺度律和不稳定性分析等关键力学问题,总结射流不稳定性的研究方法和已取得的成果,最后展望流动聚焦的研究方向和应用前景.
[Abstract]:Flow focusing is an effective micro-jet generation method. Its principle can be described as that the fluid flowing out of the capillary tube is driven by another kind of high speed moving fluid, and after focusing through a small hole, it forms a stable cone-jet structure. The jet is broken into monodisperse droplets due to instability. Since the introduction of flow focusing in 1998, capillary flow techniques such as uniaxial flow focusing, electric flow focusing, composite flow focusing and microfluidic flow focusing have been developed one after another. These technologies are stable, easy to operate and do not require harsh environmental conditions. They can be used to prepare droplets, particles and capsules with good monodispersity, which are of great value in scientific research and practical application. Flow focusing involves complex hydrodynamic problems with multi-scale, multi-interface and multi-field coupling, in which stable cones are prerequisites for the formation of stable jets, and process parameters are the key factors affecting the development of jet interface disturbances. The analysis of jet instability is the main theoretical tool to reveal jet breakage. This paper reviews the research progress of flow focusing in different structures in the past two decades, and summarizes the key mechanical problems involved in these techniques, such as process control, flow model, scale law and instability analysis. The research methods and achievements of jet instability are summarized. Finally, the research direction and application prospect of flow focusing are prospected.
【作者单位】：中国科学技术大学近代力学系;
【基金】：国家自然科学基金项目资助(11472270,81327803,11621202)
【分类号】：O358

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