射流温度场与拟序结构间相互作用的大涡模拟

本文分别对常温空气和高温空气的平面自由射流进行了大涡模拟，采用分步投影法求解动量方程，亚格子项采用标准Ｓｍａｇｏｒｉｎｓｋｙ亚格子模式模拟，并同时求解了标志物输运方程以实现数值流场显示。模拟结果给出了湍流的瞬态发展过程以及流动中拟序结构的发展演变过程，通过对常温射流和高温射流瞬态流场的比较揭示了射流中温度场与拟序结构间相互作用的细节过程。

LES OF INTERACTION BETWEEN TEMPERATURE DISTRIBUTION AND COHERENT STRUCTURES

In this paper, numerical simulations of two-dimensional spatially developing planar jets with different inlet temperature are carried out by using LES method. The motion of small-scale structures are described by standard Smagorinsky SGS model. Transport equation of passive scalar is also solved in order to perform numerical visualization of flow field. Simulation results give detaild information of vortexes evolution process and transient distribution of temperature in planar jet. Comparison between air jets of moderate temperature and high temperature is also given. It is found that temperature distribution depends on and also acts on evolution of coherent structures intensively. Large temperature gradient cause intensive diffusion and mixing in flow field, which might has constructive effect on enhancement of turbulent combustions.