中文摘要：

在在超声的流动的一个旋涡发电机(VG ) 附近的密度领域被学习，基于 nanoparticle 的平面激光(NPLS ) 散布方法。基于刻度，即，在楔附近的超声的流动的密度分发，超声的 VG 的密度领域被测量。根据 VG 的流动领域和小浪的基本概念里的协调结构的运动特征，波动表明的密度和密度领域图象的多决定特征被学习。密度变化的多决定特征能与 NPLS 图象的小浪转变被分析。密度波动信号的近似系数展出的小浪他们在不同规模的特征，和相应详细系数显示出多样的层的差别光滑的近似在某些方面。基于 2D 小浪分解和密度领域图象的重建，近似并且在不同规模的详细信号被学习，并且在不同规模的协调结构被提取并且分析。

英文摘要：

The density field around a vortex generator （VG） in supersonic flow is studied with a nanoparticle-based planar laser scattering （NPLS） method. Based on the calibration, i.e., the density distribution of the supersonic flow around a wedge, the density field of a supersonic VG is measured. According to movement characteristics of coherent structure in VG’s flow fields and the basic concepts of wavelet, the density fluctuating signals and multi-resolution characteristics of density field images are studied. The multi-resolution characteristics of density fluctuation can be analyzed with wavelet transformation of NPLS images. The wavelet approximate coefficients of density fluctuating signals exhibit their characteristics at different scales, and the corresponding detail coefficients show the difference of diverse layer smooth approximation in some way. Based on 2D wavelet decomposition and reconstruction of density field images, the approximate and detail signals at different scales are studied, and the coherent structures at different scales are extracted and analyzed.