流化床中液固物性参数对流场影响的数值模拟

发布时间：2018-04-11 00:03

本文选题：流化床 + 液固耦合　；参考：《武汉大学学报(工学版)》2016年01期

【摘要】：考虑液固两相间耦合作用,采用欧拉-欧拉双流体模型,运用RNGk-ε模型和速度-压力耦合的SIMPLE算法求解粘性项的方法来模拟流化床中液固两相流动的特性,评估了曳力模型的适用性,研究了流化床的床层流动特性、液体不同物性和操作条件下对两相流动的影响.模拟仿真中发现:RNGk-ε模型比标准k-ε模型计算更为精确,运用不同的曳力系数模型会对计算结果造成重要影响,其中曳力模型Syamlal-O’Brien比Gidaspow更适用流化床中液固耦合特性的研究;惰性颗粒的速度会随着液体粘度参数的增大而增大,而且惰性粒子在流化床中心处速度最大即惰性粒子在流化床中心的沉降速度最慢;液体密度参数的增大会导致惰性粒子速度增大;惰性粒子的体积分数的改变也会影响颗粒的速度分布,且不成线性关系.
[Abstract]:Considering the interaction between liquid and solid phases, Euler-Euler two-fluid model is used to simulate the characteristics of liquid-solid two-phase flow in fluidized bed by using RNGk- 蔚 model and SIMPLE algorithm of velocity-pressure coupling to solve the viscous term.The applicability of the drag model was evaluated and the effects of the fluidized bed flow characteristics, liquid physical properties and operating conditions on the two-phase flow were studied.In the simulation, it is found that the weight RNGk- 蔚 model is more accurate than the standard k- 蔚 model, and the application of different drag coefficient models will have an important effect on the calculation results. The drag model Syamlal-O'Brien is more suitable for the study of liquid-solid coupling characteristics in fluidized bed than that of Gidaspow.The velocity of inert particles increases with the increase of viscosity parameters, and the velocity of inert particles at the center of the fluidized bed is the largest, that is, the settling velocity of the inert particles in the center of the fluidized bed is the slowest.The velocity of inert particles will be increased with the increase of liquid density parameters, and the velocity distribution of particles will be influenced by the change of volume fraction of inert particles, and there is no linear relationship between them.
【作者单位】：湖北工业大学机械工程学院;重组烟叶应用湖北省重点实验室;
【基金】：湖北省自然科学基金项目(编号:2012FFA059) 武汉大学水力机械过渡过程教育部重点实验室开放基金项目(2015)
【分类号】：O359

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