摘要
使用大涡模拟方法,研究了高雷诺数时分离盘长度对圆柱绕流特性的影响,对不同长度分离盘下作用在圆柱体上的升力系数、拖曳力系数以及尾部流场的无量纲漩涡泄放频率(strouhal数)以及漩涡泄放形态进行了对比分析.分析结果表明:依据升力系数以及拖曳力系数随时间历程的变化特性可以将分离盘长度大致划分为3个区间,分别为稳定区间Ⅰ(分离盘长度L=0D时,D为圆柱直径)、非稳定区间Ⅱ(L=0.5D-1.0D)以及再稳定区间Ⅲ(L=1.5 D-8.0D).当分离盘长度从区间I变化到区间Ⅱ时,Strouhal(Sr)数出现突降;当分离盘长度从区间Ⅱ变化到区间Ⅲ时,Sr出现突升.随着分离盘长度的增加,圆柱尾部流场的漩涡泄放形式从2S模式(即从圆柱两侧每次只泄放单个漩涡)逐渐转化为2P模式(即从圆柱两侧每次同时泄放2个漩涡).
Influence of splitter plate length on characteristics of flow past a circular cylinder at high Reyn olds numbers is investigated using large eddy simulation （IRES）. Lift coefficients, drag coefficients, Strou- hal numbers and vortex shedding patterns of different splitter plate lengths are compared and analyzed. The results of analysis show： based on the time histories of lift coefficients and drag coefficients, the split- ter plate lengths could be divided into three regimes, which are the stable regime I （when the splitter plate length L=OD, D is the diameter of the circular cylinder）, the unstable regime II （L=0.5D-1.0D）, and the stable again regime III （L= 1.5D--8.0D）. When splitter plate length changes from regime I to regime II, there is a sudden drop of Strouhal number. When splitter plate length changes from regime II to regime III, there is a sudden increase of Strouhal number. With the increase of splitter plate length, the vortex shedding pattern of flow field changes from 2S to 2P.
出处
《上海交通大学学报》
EI
CAS
CSCD
北大核心
2017年第4期504-512,共9页
Journal of Shanghai Jiaotong University
基金
国家自然科学基金(51609206
51522902
51379033)
国家留学基金(201608515007)资助项目
关键词
圆柱体
分离盘
大涡模拟
高雷诺数
流场特性
Circular cylinder
Splitter plate
Large eddy simulation
High Reynolds numbers
Flow characteristics
