非牛顿流体鼓泡床中微泡群的动力学调控及传质特性研究

The dynamics characteristics of microbubble swarms in bubble column equipped with non-Newtonian fluid are investigated. High-speed camera combined with bi-electric conductivity probe is employed to measure dynamics behavior of bubbles swarm under the cooperative effect of micropore structure and surfactant. The discrimination graph of flow regime, theoretical models of dynamics feature parameters and regime transition point are developed respectively on the basis of nonlinear analysis of various influencing factors. The influence mechanism of cooperative effect on bubble swarms dynamics in non-Newtonian fluid is studied. By considering surface tension between two phases and the rheological property of non-Newtonian fluid, computational fluid dynamics coupled with population balance method (CFD-PBM) is applied to simulate the microbubble swarms dynamics. The simulation results are compared with the experimental measurements to study the rule of microbubble swarms under the cooperative effect. The research results are therefore essential to the understanding of both the complex bubble swarms behaviors and mass transfer mechanism, helpful to enhance transfer efficiency between gas-liquid phases sufficiently and reasonably, so as to provide theoretical foundation in industrial design.

对非牛顿流体鼓泡床中微泡群的动力学特征进行研究。采用高速摄像仪结合双电导探针技术观测在微孔结构和表面活性剂协同效应下泡群动力学行为，基于各影响因素的非线性分析，建立流型分区图谱，以及动力学特征参数、流型转变点的理论模型，研究协同效应对非牛顿流体中泡群动力学的影响机理；考虑两相间表面张力及非牛顿流体流变特性，采用耦合计算流体力学-群平衡模型（CFD-PBM）方法对鼓泡床中微泡群的动力学行为进行模拟计算，结合实验测量结果，对协同效应下微泡群特征对比研究，有助于高效、合理地增强相际传递效率，为工业设计提供理论基础。

本项目以研究非牛顿流体鼓泡床中微泡群的动力学调控为目的，旨在利用通过微孔分布器以及调控气液界面张力来产生微泡群，研究非牛顿流体中微泡群的动力学行为。重点考虑了非牛顿流体的流变特性和相界面张力，利用耦合计算流体力学和颗粒群体平衡模型的方法（CFD-PBM）三维模拟了非牛顿鼓泡床中微泡群上升行为，考察了气体表观流速、液面高度、气体分布器尺寸以及溶液性质对鼓泡床的气含率、Sauter直径、泡群的湍动能以及液体流速进行深入研究，重点研究了各核心参数在不同空间的分布规律和对其的调控措施。此外，分别采用激光影像技术和耦合水平集法/流体体积法（CLSVOF）对平行微泡对的生成规律及聚并机理进行研究，利用激光多普勒测速仪（LDA）对非牛顿流体中微泡串进行流场研究，旨在从水平和垂直两个方向进一步揭示相邻微泡间相互作用机理，为微泡群之间的复杂动力学作用机理提供有力理论支持。项目的研究成果能够促进对复杂的微泡群相互作用及传质机理的理解，有助于高效、合理地增强相际传递效率，为工业应用和设计提供理论基础。