基于不同收缩曲线的圆射流流场拟序结构分析∗

摘要

In order to analysis the effect of different contraction curve on the external flow field of round jet, a numerical simulation, large eddy simulation, is conducted to study the contractive section of external flow field with sine curve, bicubic curve, Witozinsky curve contractive nozzle. Based on the comparison, the nozzle with sine curve is superior to the other two nozzles, with bicubic curve or Witozinsky curve respec-tively, in the distribution of the velocity and turbulence intensity in outlet. The initial shear layer is thin in the external flow field, and the vortex ring rolled and paired is obviously observed in this field. In addition, the result of the simulation of the external flow field with sine contraction curve nozzle is almost in accord-ance with the image get from the experiment.%为了分析不同的收缩曲线对喷嘴外部流场中流场结构的影响，利用大涡模拟方法，对具有正弦曲线、双三次曲线、维多辛斯基曲线的收缩段的外部流场进行了数值模拟，通过对比分析，正弦曲线喷嘴出口处的速度分布、湍流强度分布均优于其余两种曲线，并且其初始剪切层较薄，外部流场中涡环的卷起、配对现象明显，正弦收缩曲线的收缩段的外部流场的模拟结果与实验图像结果基本相符。