活性流体强化气液宏观传质的介尺度行为及流体动力学效应

Based on the theories of multiphase fluid mechanics, mass transfer and bacterial hydrodynamics, this project studies the gas-liquid two-phase flow and mass transfer enhancement process in Escherichia coli suspensions. The Escherichia coli suspensions are considered to be typical representative active fluids. The law of gas-liquid two phase macro flow and mass transfer of active fluids is obtained, and the swimming bacteria’s mesoscale behavior and their hydrodynamic effect are revealed. The application of active fluids to gas-liquid two phase mass transfer enhancement and the related regulation mechanism are explored. On the macroscopic scale, the rheological properties and diffusion mechanism of swimming bacterial suspensions are studied, and furthermore, the rising behavior and mass transfer enhancement of single bubble in bacterial suspensions are experimentally and numerically investigated. On the mesoscopic scale, the microenvironment of gas-liquid two-phase flow is simulated based on the microfluidic technology, and the hydrodynamic behavior of swimming bacteria in the shear flow and the neighborhood of the gas-liquid interface is experimentally studied. A mathematical model combining flagellar propulsion, Brownian motion, tumbling and external fluid flow is proposed to simulate the mesoscale behavior of bacteria in complex fluid environment. By analyzing the experimental data and numerical simulation results, the functionary mechanism of the mesoscale behavior of swimming bacteria on the macro gas-liquid mass transfer enhancement is obtained. The achievements of this project have significant theoretical value and guiding significance for enriching the mass transfer theory and promoting the practical application of active fluids in the field of mass transfer.

本项目综合运用多相流体力学、传质学和细菌流体动力学理论，研究大肠杆菌悬浮液为典型代表的活性流体的气液两相流动和传质强化过程，明确活性流体的气液两相宏观流动和传质规律,揭示泳动细菌的介尺度行为及流体动力学效应，寻求将活性流体应用于气液传质过程强化的方法和调控机制。在宏观尺度上，本项目研究泳动细菌悬浮液流变性质和扩散机制，实验测试和模拟分析细菌悬浮液中单气泡的上升行为和传质强化规律。在介观尺度上，基于微流控技术模拟大肠杆菌在气液传质过程中所处的微环境，实验研究剪切流中和气液界面附近泳动细菌的流体动力学行为；建立综合描述细菌鞭毛推进、布朗运动、翻滚行为和外部流动的数学模型，模拟计算细菌在复杂流体环境下的介尺度行为；分析实验数据和模拟计算结果，探明泳动细菌介尺度行为强化气液宏观传质的作用机制。本项目的成果对丰富传质理论内涵、推动活性流体在传质领域的实际应用具有重要的理论价值和指导意义。

本项目综合运用多相流体力学、传质学和细菌流体动力学理论，研究大肠杆菌悬浮液为典型代表的活性流体的气液两相流动和传质强化过程，明确活性流体的气液两相宏观流动和传质规律,揭示泳动细菌的介尺度行为及流体动力学效应，寻求将活性流体应用于气液传质过程强化的方法和调控机制。在宏观尺度上，本项目研究泳动细菌悬浮液流变性质和扩散机制，实验测试和模拟分析细菌悬浮液中单气泡的上升行为和传质强化规律。在介观尺度上，基于微流控技术模拟大肠杆菌在气液传质过程中所处的微环境，实验研究剪切流中和气液界面附近泳动细菌的流体动力学行为；建立综合描述细菌鞭毛推进、布朗运动、翻滚行为和外部流动的数学模型，模拟计算细菌在复杂流体环境下的介尺度行为；分析实验数据和模拟计算结果，探明泳动细菌介尺度行为强化宏观气液传质的作用机制。本项目的成果对丰富传质理论内涵、推动活性流体在传质领域的实际应用具有重要的理论价值和指导意义。