Abstract:

In this paper, a particle-resolved simulation of the solid-liquid suspension in a turbulent stirred tank was presented, where the stirring Reynolds number Re=9800 and the solid particles were in a partially suspended state. The lattice-Boltzmann method was employed to simulate the liquid phase flow directly and the motion of the solid particles was resolved at the particle scale based on the immersed boundary method. In order to validate the results of the numerical simulations, the particle-resolved PIV experiments were performed to investigate the average velocity fields and the distribution of turbulent kinetic energy of the liquid phase under the conditions with particle volume fractions ranging from 1% to 8%. The results demonstrated a good agreement between the particle-resolved simulations and the PIV experimental data. The simulation methodology presented in this paper could offer a novel perspective for modeling the complex interactions among the solid particles and between the particles and the liquid phase flow in the solid-liquid two-phase stirred systems.

Key words: solid-liquid suspension, stirred tank, turbulence, lattice-Boltzmann, particle-resolved simulation

摘要：

针对湍流搅拌槽内固液悬浮过程进行了颗粒解析的数值模拟：搅拌雷诺数Re=9800，固体颗粒处于部分悬浮状态。采用格子玻尔兹曼方法对液相流体进行直接数值模拟，并基于浸没边界法在颗粒尺度下解析固体颗粒的运动。为验证数值模拟结果，利用颗粒解析PIV实验获得了颗粒体积分数在1%~8%工况下液相平均速度场和湍流动能分布。结果表明，颗粒解析数值模拟结果与PIV实验数据吻合良好。本文模拟方法可为模化固液两相搅拌体系中固体颗粒间以及颗粒与液相流体间复杂相互作用提供一种新思路。

关键词: 固液悬浮, 搅拌槽, 湍流, 格子玻尔兹曼, 颗粒解析模拟