湍流分离流中颗粒的扩散机制

发布时间：2018-03-11 05:22

本文选题：后台阶流动　切入点：分离流　出处：《上海大学学报(自然科学版)》2016年05期 　论文类型：期刊论文

【摘要】：后台阶流动包含分离流重要的流动特性,采取欧拉-拉格朗日耦合算法对后台阶分离流动中颗粒扩散运动进行数值研究.气相场采取大涡模拟方法,亚格子模式基于标准的Smagorinsky模式,颗粒相运动采取轨道法模拟.计算所得气相的流向平均速度和平均脉动速度与实验结果吻合较好,验证了模型和方法的正确性.基于此,数值分析后台阶两相流动的特性以及流场涡结构的发展和演化过程.结果表明:两相流中颗粒的扩散特性既受到颗粒粒径的影响,又与颗粒和涡结构的相互作用时间有关.后台阶流场中增加结构物时,流场涡结构发生变化,即与扰动源保持一定距离后,涡数量增多,流场中颗粒分布不均匀,较多颗粒聚集在涡的外缘.
[Abstract]:The backward step flow contains the important flow characteristics of the separated flow. The particle diffusion motion in the backward step separation flow is studied numerically by using the Euler-Lagrangian coupling algorithm. The gas phase field is simulated by large eddy method. The sublattice model is based on the standard Smagorinsky model, and the particle phase motion is simulated by the orbital method. The calculated gas phase flow average velocity and average pulsating velocity agree well with the experimental results, which verify the correctness of the model and method. The characteristics of the two-phase flow in the backward step and the evolution and development of the vortex structure in the flow field are numerically analyzed. The results show that the diffusion characteristics of the particles in the two-phase flow are affected not only by the particle size, but also by the evolution of the vortex structure. It is also related to the interaction time between particles and vortex structure. When the structure is added to the back step flow field, the vortex structure of the flow field changes, that is, after maintaining a certain distance from the disturbance source, the number of vortices increases and the particle distribution in the flow field is not uniform. More particles gather on the outer edge of the vortex.
【作者单位】：上海大学上海市应用数学和力学研究所;
【基金】：国家自然科学基金资助项目(11472167)
【分类号】：O357.5

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