基于高粘度介质对气液两相混合的数值模拟

Numerical Simulation of Gas-Liquid Two-Phase Mixing Based on High Viscosity Medium

摘要: 为了探究高粘度介质在泰勒涡釜式搅拌反应器内的气液流动与混合特性，采用数值模拟与实验相结合的方法，通过对比分析在不同介质下，反应器内泰勒涡流对流场、气含率及速度分布的影响。结果表明：在低粘度介质的流场内，能在250 rpm转速下，快速地形成满涡泰勒涡，泰勒涡能促进气相均布性，同时增强气液相间传质，但容易失稳，满涡结构仅能在较窄的转速范围内维持稳定；在高粘度介质的流场内，在550 rpm转速下形成的满涡泰勒涡胞具有数量多、分布均匀、大小相似、形状规则等特点，能够抑制气液相间传质，且满涡结构能够在较宽的转速范围内维持稳定，同时使轴向上的速度出现分层分级现象，具有类似正弦的周期性变化规律，不同高度径向上的速度均匀性提升20.5%，增强了反应器内的流动稳定性。研究结果为高粘度介质在泰勒涡釜式搅拌反应器内的工业应用提供了理论基础。

Abstract: In order to explore the gas-liquid flow and mixing characteristics of high-viscosity media in Taylor vortex stirring reactor, the effects of Taylor vortex on flow field, gas content and velocity distribu-tion in the reactor under different media were compared and analyzed by combining numerical simulation and experiment. The results show that the full vortex Taylor vortex can be formed rap-idly at 250 rpm in the flow field of low-viscosity medium, which can promote the homogeneity of the gas phase and enhance the mass transfer between the gas and liquid phases, but it is easy to lose stability, and the full vortex structure can only maintain stability in a narrow speed range. In the flow field of high-viscosity medium, the full vortex Taylor vortex cells formed at 550 rpm have the characteristics of large number, uniform distribution, similar size, regular shape, etc., which can in-hibit the mass transfer between gas and liquid, and the full vortex structure can maintain stability in a wide range of speeds, and at the same time, the axial velocity appears layered and classified, with a periodic change law similar to sinusoidal, and the speed uniformity in the radial direction of different heights is increased by 20.5%, which enhances the flow stability in the reactor. The results of this study provide a theoretical basis for the industrial application of high- viscosity media in Taylor vortex stirred reactors.