速度滑移条件下气体-微颗粒两相流动数值模拟研究

Numerical simulation of gas-micro particle fluid flow considering velocity slip effect

中文关键词: 气粒两相流  微尺度效应  速度滑移  欧拉-拉格朗日模型

英文关键词: gas-particle two-phase flow  micro-scale effect  velocity slip  Euler-Lagrangian model

中文摘要:

      本文基于欧拉-拉格朗日方法构建了气体-微颗粒两相流动数值计算模型,采用考虑速度滑移的拖曳力系数关联式以研究微颗粒表面动量非平衡效应。在此基础上,分析速度滑移、斯托克斯数(St)对微颗粒在受限空间中运动轨迹的影响规律。研究结果表明:速度滑移对颗粒运动轨迹影响明显,其运动过程明显滞后于常规颗粒运动；St数较小时,颗粒能及时响应流场变化,可较好地跟随流体运动,随St数增大,颗粒运动受自身惯性影响愈加明显。

英文摘要:

      A two-phase numerical model was established to study gas-microparticle flow in the channel based on the Euler-Lagrangian approach, in which a new micro-scale drag coefficient correlation was adopted to consider the rarefication effects on the micro particle surface. The influences of micro-scale effect (velocity slip) and Stokes number on the particle motion were explored. It was found that the micro-scale effect on the particle surface will decrease the drag force, which leads to the micro particles moving behind the macro particles. Moreover, the particles with smaller Stokes number respond to the variation of flow more quickly, while the particles with larger Stokes number can’t be used to characterize the variation of flow field due to the inertial force effect.