网格尺度、时间步长和颗粒堆积率对射流床CFD模拟的影响  

Effects of Grid Scale, Time Step and Maximum Solid Volume Fraction on CFD Simulation in a Jetting Fluidized Bed

作　　者：裴培[1] 王其成[1] 张锴[1] 文东升[2] 

机构地区：[1]中国石油大学(北京)重质油国家重点实验室,北京102249 [2]伦敦大学玛利女王学院工程系,英国E14NS

出　　处：《过程工程学报》2008年第6期1057-1063,共7页The Chinese Journal of Process Engineering

基　　金：国家重点基础研究发展规划(973)基金资助项目(编号:2005CB221205);国家自然科学基金资助项目(编号:20490200;20576076)

摘　　要：采用欧拉-欧拉双流体模型,在CFX4.4软件上增加用户自定义子程序模拟了高2.0m、宽0.3m的二维射流床内空气和玻璃珠体系的流体动力学特性.考察了网格尺度、最大颗粒堆积率和时间步长对射流的形成及发展过程、射流穿透深度及射流频率的影响,并与实验数据进行了对比.结果表明,对于本研究的气固体系,当床层下部纵向网格数为100、时间步长0.0005s时,不仅可以满足网格尺度和时间步长的无关性要求,而且模拟的射流穿透深度和射流频率与实验测量值的误差分别为5.7%和3.8%.最大颗粒堆积率在本研究范围对模拟结果的影响可以忽略.Based on the Eulerian-Eulerian two-fluid model, the hydrodynamics was simulated in a two-dimensional jetting fiuidized bed with 2.0 m height and 0.3 m width. Air and glass bead were chosen as gas and solid phases, respectively. The effects of grid scale, time step and maximum solid volume fraction on jetting parameters, such as jet revolution, jet penetration depth and jet frequency, were investigated numerically with CFX4.4 by adding User-defined Fortran subroutines. The computational results are independent of mesh size and time step for the gas-solid system used, when vertical grid number is 100 in the lower part of the bed and time increment 0.000 5 s. The relative errors of simulated jet penetration depth and jet frequency with their corresponding experimental measurements are 5.7% and 3.8%, respectively. The influence of the maximum solid volume fraction on numerical data can be ignored in the range of this study.

关 键 词：气固射流床 实验测量 CFD模拟 网格尺度 时间步长 最大颗粒堆积率 

分 类 号：TQ018[化学工程]