子波分析辨识壁湍流猝发事件的能量最大准则

用子波分析的方法，对用热膜测速仪得到的平板湍流边界层中流向脉动速度信号，在时域空间和频域空间同时进行时频双局部化分解．用子波系数研究了壁湍流脉动动能随尺度的分布，提出了确定壁湍流猝发事件时间尺度参数的能量最大准则，用子波逆变换得到了猝发事件对应的速度信号波形

THE MAXIMUM ENERGY CRITERION FOR IDENTIFYING BURST EVENTS IN WALL TURBULENCE USING WAVELET ANALYSIS

In this paper, the wavelet analysis method is used to perform the time frequency double local decompositions for the signal of streamwise fluctuating velocity both in time space and in frequency space. The signal is obtained from a hot film anemometer output in an experimental study of turbulent boundary layer over a smooth flat surface. The energy evolution of fluctuating velocitywith scales is studied using the wavelet coefficients. The maximum energy criterion is proposed to determine the time scale that is related to burst events in wall turbulence. The velocity signal corresponding to burst events is extracted from the fluctuating velocity.