壁面滑移系数对多维度矩形喷动床气固流场影响的数值计算  

Numerical simulation of specularity coefficient effect on the hydrodynamics of multi-dimensional slot-rectanglar spouted bed

作　　者：王肖肖[1] 宋一鸣[1] 滕海鹏[1] 张小里[1] 

机构地区：[1]西北大学化工学院,陕西西安710069

出　　处：《西北大学学报（自然科学版）》2017年第2期237-244,共8页Journal of Northwest University（Natural Science Edition）

基　　金：陕西省自然科学基金资助项目(2013JK0691);陕西省科学技术研究发展计划项目工业攻关类基金资助项目(2014K10-21);陕西省教育厅科研计划基金资助项目(14JK1729)

摘　　要：基于计算流体力学(CFD)的方法,在欧拉-欧拉双流体模型框架下结合颗粒动理学理论,使用不同的颗粒壁面滑移系数对二维、准二维和三维不同维度的喷动床进行了数值计算。为了节约计算资源均采用轴(面)对称网格进行模拟,得到了不同维度喷动床的喷动过程云图、在不同滑移系数下颗粒体积分数云图、颗粒轴向速度轴向分布图。结果表明:相同边界条件下不同维度的喷动床喷动过程气泡生长速率有所差异。随着壁面滑移系数增大即颗粒壁面摩擦力增大,导致3个维度喷动床在中心处喷泉区的高度降低,同时颗粒轴向速度的轴向分布均也呈减小趋势;准二维床层较薄,导致颗粒在轴心处的运动还处于颗粒流体在壁面的速度边界层内,相对于二维和三维床层对壁面滑移系数更敏感。In the framework of Euler-Eulerian two-fluid model, multi-dimension spouted beds, including two- dimensional, quasi two dimensional and three-dimensional, were numerically analyzed with the help of compu- tational fluid dynamics in conjunction with kinetic theory of granular flow. To save computational resources, symmetric grid was used in all simulation. The spouting process of various bed dimensions, the volume fraction of particle and the axial velocity distribution of particle along the bed axis for different speeularity coefficients were obtained. The results indicate that the bubble growth rate with the same boundary condition of various bed dimensions has a wide variety. The increasing of the specularity coefficient, which means the frictional force increasing, leads to decreasing of the fountain height and the axial distributions of particle velocity in the bed center. However, the quasi two-dimensional bed is more sensitive to the specularity coefficient compared to two-dimensional and three-dimensional beds, since the quasi two-dimensional bed has a relative small value in the thickness, which leads to the movement of the particles along the axial center still under the influence of granular velocity boundary layer of the wall.

关 键 词：喷动床 颗粒动理学理论 多维度 滑移系数 

分 类 号：Q814.2[生物学—生物工程]