Numerical prediction of erosion in elbow based on CFD-DEM simulation
Numerical prediction of erosion in elbow based on CFD-DEM simulation
复制标题
基于CFD-DEM模拟的弯头冲蚀数值预测
DOI：
10.1016/j.powtec.2016.08.050
复制
发表时间：
2016
影响因子：
5.2
通讯作者：
赵永志
中科院分区：
文献类型：
--
作者：
许磊;张骞;郑津洋;赵永志
采用一种新的冲蚀模型SIEM(剪切冲击能模型)对不同工况下的弯头冲蚀进行了数值模拟。模拟中流体运动采用CFD(计算流体力学)方法，颗粒运动采用离散单元法(DEM)计算。采用CFD-DEM中的单向耦合方法和双向耦合方法计算气固相互作用。并与相应的实验数据进行了对比，验证了稀气两相流条件下弯头冲刷的预测结果。由于DEM和SIEM可以方便地应用于稠密气固两相流动，因此还研究了颗粒浓度对冲刷的影响。模拟结果表明，当颗粒浓度较低时，耦合方法对冲刷预报影响不大，而弯头冲刷对颗粒浓度的影响较大。最后，还对摩擦系数、恢复系数和弹簧刚度系数对弯头冲蚀的影响进行了仿真研究，结果表明，摩擦系数、恢复系数和弹簧刚度系数对弯头冲蚀的影响不如浓度显著。
A new erosion model, which is referred to as SIEM (shear impact energy model), is used to investigate elbow erosion under different working conditions using numerical simulations. The fluid motions are predicted by CFD (computational fluid dynamics), and the particle movements are calculated using DEM (discrete element method) in the simulations. Both a one-way coupling method and a two-way coupling method in CFD-DEM are adopted to calculate the gas-solid interaction. The prediction results of elbow erosion subject to a condition of dilute gas-particle flow are validated against corresponding experimental data. Because DEM and SIEM can be easily applied to dense gas-particle flows, the effect of the particle concentration on the erosion is also investigated. The simulation results show that the coupling methods have little influence on the erosion prediction when the particle concentration is low, whereas erosion in the elbow is significantly sensitive to the particle concentration. Finally, the effects of the friction coefficient, restitution coefficient and spring stiffness coefficient on elbow erosion are also investigated using simulations, and the effects were not as remarkable as the concentration.