摘要
为了揭示颗粒在湍流分离流动中的弥散机制,采用大涡模拟方法和颗粒轨道模型,对二维后台阶分离流动中颗粒弥散进行了数值模拟研究。研究给出了不同St数的颗粒在流场中的分布以及瞬时大涡与颗粒相互作用规律,表明大尺度涡对颗粒弥散的影响依赖于颗粒的尺寸等参数。不同St数下颗粒瞬时弥散机制不同,共有3种模式:随着颗粒St数的增大顺序表现为大涡作用模式;大涡与离心力作用模式;惯性力作用模式。进一步分析得到了颗粒进入回流区是大涡与颗粒的相互作用以及壁面的存在共同导致的结果。
The particle dispersion mechanism in turbulent separated flow was studied numerically by analyzing the particle dispersion in the separated flow behind a two-dimensional backward facing step. The gas flow was simulated using a large eddy simulation with the solid particle motion traced by the particle track model. The simulations show the particle distribution variation for various different St numbers in the flow field and the regularity of the interaction between the large eddy structures and the particles. The results show that the effect of the large eddies on the particle motion depends on the particle parameters such as particle size. The particle dispersion mechanism differed for different St numbers. Three modes are identified, the large eddy structure transport mode for StO(1), a combined large eddy structure and centrifugal force transport mode for St^O(1), and an inertia force transport mode for StO(1). The particles enter the re-circulating region due to particle-vortex interactions and wall bonding in the separated flow.
出处
《清华大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2003年第11期1507-1510,共4页
Journal of Tsinghua University(Science and Technology)
基金
国家自然科学基金资助项目(19972026)
关键词
湍流
分离流动
颗粒弥散机制
多相流
涡-颗粒相互作用
大涡模拟
颗粒轨道模型
multiphase flow
particles dispersion
vortex-particle interaction
large eddy simulation
particle track method
separation flow
