摘要
基于FLUENT软件信息传递模式的多点接口(MPI)并行计算平台,在二次开发框架内通过用户自定义函数(UDFs)文件发展计算流体力学-离散单元法(CFD-DEM)耦合并行算法.该算法具有随计算节点数增加的良好扩展性能和加速性能.采用该算法数值模拟了单沉浸管流化床内的颗粒混合过程,揭示了气固两相的运动特性和颗粒混合机制,考察了沉浸管的磨损特性.结果表明:沉浸管引起床内气泡的聚并和破碎,气泡主要绕沉浸管而非沿两侧壁向上移动,随着表观气速的增加,气相流场沿径向的分布更加均匀;颗粒宏观流动结构与分布呈现出明显的径向非均匀特性;沉浸管的存在和表观气速的增加均有助于颗粒混合,使颗粒达到完全混合的时间减少;颗粒撞击管壁的频次和冲刷速度是造成沉浸管磨损的主要原因.
The parallel technique for computational fluid dynamics-discrete element method（CFD-DEM）coupling model was developed through user defined functions（UDFs）in the framework of secondary development based on message passing interface（MPI）platform of FLUENT software.The algorithm has good scalability and speed-up performance with the increase in the number of computing nodes.Numerical simulation of the particle mixing processes in the fluidized bed with immersed tube was conducted by the developed parallel CFD-DEM coupling model.The gas-solid hydrodynamics and particle mixing mechanism were explored,and the erosion properties of the immersed tube were surveyed.Simulation results show that the immersed tube causes bubble coalescence and breakage.The preferential path of bubble motion mainly lies around the tube rather than near the walls.The radial distribution of bubble phase becomes more homogeneous with superficial gas velocity increasing.The radial heterogeneities of the solid flow and distribution are exhibited.Both of the existence of immersed tube and the increase in superficial gas velocity are helpful for particle mixing and for decrease in the time for full mixing status.The erosion quantity mainly depends on the impact frequency and particle velocity.
出处
《浙江大学学报（工学版）》
EI
CAS
CSCD
北大核心
2015年第1期150-156,共7页
Journal of Zhejiang University：Engineering Science
基金
国家自然科学基金资助项目(51076084
51306104)
关键词
计算流体力学-离散单元法耦合并行模型
单沉浸管流化床
流动特性
颗粒混合
磨损
parallel computational fluid dynamics-discrete element method coupling model
fluidized bed with immersed tube
hydrodynamics
particle mixing
erosion
