摘要
对空间发展的平面不可压缩湍射流拟序结构的非定常演化过程进行了大涡模拟。采用标志物浓度等值线分布示踪平面射流气相流动 ,Reynolds数为 1130 0 ,模拟结果再现了平面射流中 Kelvin- Helm holtz不稳定性的发生以及展向大尺度涡的卷起、合并、破碎过程。捕获到了射流拟序结构剧烈相互作用的“偶极子”和“三极子”现象。在拟序结构的配对过程中 ,大尺度旋涡的尾迹混合形成了流向“发卡”型拟序涡结构。平面射流拟序结构的时空演化过程所呈现出的卡门涡街特征主要集中于初始段的后部和过渡段的前端。
Coherent structure evolutions were investigated numerically for an unforced spatially developing turbulent planar jet at a mediate Reynolds number of 11300. A passive scalar transport equation is introduced for numerical visualization. The finite difference technique is adopted to solve the two dimensional, time dependent incompressible conservation equations with a fractional step projection method. Valid inflow and outflow boundary conditions implemented lead to the proper presentation of the vortex dynamics in the jet flow. Essential features of the coherent structure evolution were reproduced in good agreement with the results observed in experiments, such as the 'Batchelor's couples' or tri poles phenomena and a regular quasi 2D Von Kármán street in the planar jet.
出处
《清华大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2001年第11期31-34,共4页
Journal of Tsinghua University(Science and Technology)
基金
国家自然科学基金资助项目 (5 94760 3 8)
关键词
拟序结构
大涡模拟
平面射流
数值模拟
不可压缩流动
coherent structures
large eddy simulation (LES)
planar jet
numerical simulation
incompressible flow
