微反应器限域空间内非常规流体液滴的生成、运动、聚并、传质及其耦合机理与调控

The interfacial evolution of the formation，movement and coalescence processes of unconventional fluid droplets in confined microreactor would be real-time observed and recorded by a high speed digital camera. The instantaneous flow field and concentration field around a droplet would be measured separately using a μ-particle image velocimetry (μ-PIV) and a laser holographic interference technique. The influences of the physical property of unconventional fluid, geometry and configuration parameters of system and operation conditions on the formation and flow of droplets and mass transfer between two liquid phases would be investigated experiemntally. The non-dimensional analysis, Navier-Stokes equation, convection-diffusion equation, interface instability theory, self-similar and self-organization theory would be applied to correlate the various parameters and then develop the flow pattern criterion and non-linear model of multi-phase interfacial mass transfer of unconventional fluid in micoreactor. In addition, the lattice-Boltzmann (LBM) method and the volume of fluid (VOF) method would be used to simulate the formation, movement and coalescence of droplets and mass transfer between two liquid phases in microreactor. The formation and coalescence mechanisms of droplets, evolutional dynamics of droplet interface and non-linear interfacial mass transfer mechanism would be systematically studied. Furthermore, the coupling mechanism and regulatory mechanism among interfacial evolution and flow behavior of droplet, velocity field and concentration field around droplets would also be explored.

利用高速摄像仪实时观察和记录微反应器限域空间内非常规流体液滴生成、运动及聚并的界面演化过程。采用粒子图像测速仪（μ-PIV）和显微激光全息干涉仪分别对液滴周围的流场和浓度场进行实时测量。着重考虑非常规流体的特殊物理及流体性质，深入研究系统结构参数和操作参数对液滴生成、流动、聚并和两相间传质的影响。理论上采用无量纲分析原理、Navier-Stokes方程、对流-扩散方程、界面失稳理论、自相似及自组织理论对各种参数进行关联，建立不同类型非常规流体微反应器内的流型判定准则和多相界面传质非线性预测模型。此外，采用格子-玻尔兹曼（LIB）方法和流体体积（VOF）法对微反应器内液滴生成、流动、聚并及两相间传质等过程进行数值模拟。系统研究液滴生成及聚并机理、界面演化动力学及液-液非线性界面传质机理，探索液滴界面演化及流动行为与其周围流场、浓度场之间的耦合机理和调控机制。

微反应器内液滴的精确调控是微流控技术应用的重要基础。本项目系统研究了不同构型微反应器限域空间内液滴的生成、运动、破裂及聚并行为，绘制了流型图。分别考察了微反应器构型，连续相和分散相流体的流变性，以及两相流率的影响，提出了液滴的生成机理、破裂机理及聚并机理。此外对黏弹性液滴生成和破裂过程中细丝的断裂及卫星液滴的生成动力学进行了研究，提出了卫星液滴尺寸的预测模型及调控机制。研究了T型和Y型分叉口磁流体液滴的破裂动力学，提出了磁流体液滴破裂尺寸的调控机制。对液滴周围连续相及液滴内部的流场和浓度场演化规律进行了研究，提出了微通道内相间传质模型及相间传质强化机理。