中文摘要：

自由圆湍射流的稳定性分析依赖于收集射流界面演变的定量信息：射流表面微细结构。运用高速摄影及显微技术设计实验,对微孔圆柱液体射流表面波进行捕捉。讨论了高速摄影参数对射流捕捉能力的影响。运用谱方法对射流图像作后处理研究,对比分析了谱方法及其算法参数对处理结果的影响。基于所捕捉射流图像选用Burg法对射流表面波长进行测量,并对Burg法准确度进行了验证。实测数据表明：射流表面同时包含多个尺度表面波,且局部雷诺数越大表面波尺度范围越大;射流平均表面波长与基于喷嘴出口边界层厚度的雷诺数成反比;当雷诺数小于48.62时,射流表面波长沿流向,在4倍喷嘴直径范围内单调增加,但当局部雷诺数大于48.62时,波长的单调线性变化将被打破,沿流向呈现非线性波动。

英文摘要：

The steady analysis of round turbulence liquid jet based on the collection of the quantitative information of the interface development.The quantitative information is the surface microstructure of liquid jet.This work designed the experiment based on high-speed and microscopy photography,captured the surface wave of the micropore cylindrical liquid jet.The parametrics that have significant effects on image capture were discussed here.The spectral methods that applied to the images measured were presented here.The spectral methods and the important parameters of these methods were Discussed here.The Burg method was choosed to measure the jet images,and the accuracy of this method was validated.The results show that there are multiple wave lengths in a jet surfacethe,and the scale of the surface waves is increase with the Local Reynolds numbers increase.The sizes of the surface waves are inversely proportional to the Local Reynolds numbers.In the range of four times of the nozzle diameter,the sizes of wave lengths are monotonically increase along the flow direction when the Local Reynolds numbers is small（Re_（δ_2） 48.62）.But the regular will be break and become nonlinear along the flow direction when the Local Reynolds number is larger than 48.62.