摘要
为研究超声速两相流混合机理,采用大涡模拟(LES)方法数值仿真了超声速混合层内液滴两相流流场结构.用二维盒式滤波法处理可压缩气相N-S方程,得到亚格子形式的LES控制方程;用轨道模型仿真液滴运动,并用单液滴蒸发模型模拟液滴蒸发过程.利用伪邻近法和互信息量法确定了相空间重构的嵌入维数和时间延迟,对混合层压力时间序列进行了相空间重构.分析了仿真结果中混合层的涡结构特性和液滴对流场的反作用效果,并讨论了混合层失稳过程的非线性特征.发现混合层发展的不同阶段与其系统的非线性特征值密切相关.
The two-phase compressible mixing layer with droplets was calculated by large eddy simulation （LES） for studying the mixing law of supersonic two-phase flow. To get the sub-grid LES equations, the compressible N-S equations of gaseous phase were filtered by two-dimensional box-filter function. The droplets phase was simulated by track model, and the evaporation equations of single droplet model were employed to simulate the evaporating course. The phase space for the time series of mixing layer pressure was reconstructed by determining the embedding dimension and time-delay of the phase space reconstruction, with the method of false neighbors and mutual information. The characteristic of eddy and droplets evaporation in mixing layer were analyzed, and moreover, the nonlinear characteristic of mixing layer instability was discussed. The results show that the different development stages of mixing layer is closely related with its nonlinear eigenvalue.
出处
《航空动力学报》
EI
CAS
CSCD
北大核心
2009年第1期25-31,共7页
Journal of Aerospace Power
关键词
大涡模拟
两相流
混合层
非线性
large eddy simulation
two-phase flow
mixing layer
nonlinear
