摘要
为了研究气固两相流动大涡模拟中合适的曳力计算模型,本文引入拟颗粒和拟颗粒表面能的概念,通过拟颗粒表面能与外界输入能量之间的平衡关系来确定拟颗粒的粒径。根据拟颗粒粒径,得到运算量较小且考虑颗粒团聚效应的曳力计算模型。应用本文的曳力计算模型对二维竖直槽道内稠密气固两相流动进行了大涡模拟,结果表明颗粒的浓度分布具有上稀下浓,壁面附近浓中心稀及颗粒聚集等特点。这与实验结果在定性上是一致的。对气相和颗粒相的瞬时速度场进行了分析,发现气相和颗粒相速度场分布的非对称性是形成颗粒浓度分布壁面附近浓中心稀的重要原因之一。
The concepts of virtual particles and surface energy of virtual particles are introduced to study the gas-solid drag model suitable for large eddy simulation. The diameters of virtual particles are determined by letting the surface energy of virtual particles equal to the input energy. The drag model with less computational consumption and also considering the effect of particle agglomerates is obtained according to the diameters of virtual particles. The developed drag model is applied to the large eddy simulation of the dense gas-solid flow in a vertical channel. The results of the simulation showed the cluster formation and the characteristic of the particle concentration distribution, which is dilute in top and dense in bottom, dilute in center of the channel and dense near the wall. These results agree with the experiment qualitatively. The transient gas and particle flow velocity field are analyzed. It is found that the asymmetric distribution of the gas and particle flow velocity is an important reason for the particle concentration distribution dilute in center of the channel and dense near the wall.
出处
《工程热物理学报》
EI
CAS
CSCD
北大核心
2005年第2期253-256,共4页
Journal of Engineering Thermophysics
基金
国家自然科学基金资助项目(No.50376028)
