存在热浮力的剪切湍流中颗粒近壁运动的大涡模拟  

Large Eddy Simulation of Particle Motion in Shear Turbulent Flow Due to Thermal Buoyancy

作　　者：董宇红[1] 陈林烽[1] 唐一敏[1] 

机构地区：[1]上海大学上海市应用数学和力学研究所,上海200072

出　　处：《上海大学学报（自然科学版）》2009年第6期600-606,627,共8页Journal of Shanghai University:Natural Science Edition

基　　金：国家自然科学基金资助项目(10772109;10972132);上海市教委创新基金资助项目(09YZ03);上海市科委重点基金资助项目(08JC1409800);创新团队发展计划资助项目(IRT0844)

摘　　要：采用基于动力学亚格子模型和热通量模型的大涡模拟方法,结合Lagrange粒子追踪技术,数值研究了存在热浮力作用的剪切湍流中细颗粒群的输运特性.一方面探讨在槽道剪切湍流中不同热分层效应与粒子输运的动态关联性,以及不同Stokes数的细颗粒在同一分层湍流环境下的浓度分布;另一方面探讨动量和热量耦合作用下影响粒子迁移、扩散和沉积的不同因素.此外,基于一些典型计算结果,探讨了稳定和不稳定分层对颗粒运动各向异性程度的影响,研究了不同颗粒的平均速度、脉动强度的统计特征量以及与湍流流场之间的相关性,并对颗粒在槽道不同区域的体积浓度分布和局部积聚现象进行了分析.The behavior of dilute dispersion of particles in a stratified channel flow is investigated with large eddy simulation.The three-dimensional Navier-Stokes and energy equations under the Boussinesq approximation are numerically solved using a fractional-step method based on high-order accurate temporal schemes.The Lagrangian tracking approach is used to describe the dynamics of particles.The objectives of this study are to deal with the effect of the thermal buoyancy on the behavior of particles in the thermally stratified turbulent channel flow and examine particle concentrations under the stratified turbulent environment.In the present study,some typical cases are computed.To depict the effect of the thermal stratification on the particles transport,the mean value and fluctuation of resolved velocities of particles,as well as some typical instantaneous velocity fluctuation patterns are analyzed.Numerical results provide the characteristics of particle concentrations under different Stokes numbers.

关 键 词：细颗粒物 分层湍流 大涡模拟 拉格朗日追踪法 

分 类 号：O351[理学—流体力学]