颗粒黏度模型对采用欧拉多相流模型模拟超密相颗粒流动行为的影响

颗粒黏度是欧拉多相流模型计算固体流动的重要参数之一，其数值大小依赖于摩擦压力和径向分布函数。通过与实验值对比，评估了常用的摩擦压力模型（Based、Johnson）和径向分布函数模型（Lun、Syamlal O’Brien）对密相颗粒流动体系的预测能力。模拟结果表明，Johnson模型的固体体积分数预测值低于Based模型；Syamlal O’Brien 模型固体流率的预测值远大于Lun模型。采用根据实验结果修正的欧根系数后，Based-Lun、Johnson-Lun和Johnson-SO模型组合预测的平均压降相对误差分别由68.6%、73.3%和78.2%降低至13.2%、29.7%和42.3%。综合考虑压降、固体出口质量流率、固体体积分数、壁面区域固体速度的模拟结果与实验值的偏差，发现Based-Lun模型组合的平均预测误差最小，适用于气固移动床的欧拉多相流模拟。研究还发现，欧根系数与内摩擦角对固体速度与压降有着显著的影响，而临界固含率对固体速度与压降的影响较小。

Impact of viscosity model on simulation of condensed particle flow by Euler multiphase flow model

Particle viscosity is one of important parameters for the calculation of solid flow in Euler multiphase flow model, and the value depends on the frictional pressure and radial distribution function. The predictive ability of commonly used frictional pressure models (Based, Johnson) and radial distribution function models (Lun, Syamlal O’Brien) were evaluated by comparing them with experimental results. The simulation results show that the solid volume fraction using the Johnson model is lower than that using the Based model, and the solid mass flow rate using the Syamlal O’Brien model is much larger than that using the Lun model. The relative deviations of the average pressure drop can be reduced substantially after the Ergun coefficient correction was applied. The relative predicting deviations of the Based-Lun, Johnson-Lun, and Johnson-SO models were reduced from 68.6%, 73.3%, 78.2% to 13.2%, 29.7% and 42.3%, respectively. Comprehensively considering the pressure drop, the solid mass flow rate at outlet, solid volume fraction and the solid velocity in the near-wall area, the relative average deviations of the Based-Lun model is the smallest, and the Base-Lun model is suitable for simulation of the gas-solid Euler multiphase flow. In addition, this work found the Ergun coefficient and internal friction angle have a significant effect on solid velocity and pressure drop, while the threshold volume fraction for friction has little effect.