中文摘要：

低密度固体颗粒与液体的搅拌混合过程广泛存在于许多工业过程中,为建立相对精确的固液两相混合过程数值模拟方法,指导此类搅拌器的设计并优选搅拌结构,本文对三层桨式搅拌槽内的低密度固体颗粒与液体的搅拌混合过程进行了三维数值模拟,采用多重参考系法（MRF）,选用标准k-ε湍流模式,模拟了三层桨式平底搅拌槽中的流场形态,通过搅拌混合过程的非定常两相流计算得到搅拌过程低密度固体颗粒体积分数分布情况和混合时间,最后与相关试验结果进行了定性比较。结果表明,该搅拌混合过程的CFD模拟可获得较准确的固液流场分布及各项特性参数,计算结果可为低密度固体颗粒搅拌过程提供工艺参考。

英文摘要：

Low-density solid-liquid mixing operation is used in various industry processes.In order to establish a possible method for solid-liquid mixing process simulation,and to optimize the solid-liquid mixers,three-dimensional numerical simulation of low-density solid-liquid mixing process was carried out by using computational fluid dynamics（CFD）.The multi-reference frame（MRF） and standard k-εturbulent model were used to describe the rotational turbulent flow in stirred tank,and the Euler-Euler model was used to analyze the solid-liquid two-phase flow.The calculation results of solid particle volume fraction distribution and mixing time were similar to the experimental results. It indicates that the Euler-Euler model and RANS can accurately simulate the unsteady flow of low-density solid-liquid mixing process,and the calculation results will contribute to solid-liquid mixing process operation.