基于小波分析的湍流参数提取方法

在定容燃烧弹内，利用孔板平动法生成湍流，用热线风速仪测量容弹内的速度，用小波分析技术将湍流分解为具有不同频带的组分，方便地获得了湍流强度、湍流尺度、湍流能谱等湍流特征参数。对具有不同频带的湍流积分时间尺度进行详细研究，结果表明，整个湍流的积分时间尺度代表所有湍流涡的平均寿命，与湍流频率和湍流能量分布有关。

Method to Extract Turbulent Characteristic Parameters Based on Wavelet Analysis

Turbulence is produced by using a moving perforated plate driven by a motor in a constant volume bomb and the instantaneous velocity is measured by hot wire anemometer (HWA).The data are processed with wavelet analysis technology to extract turbulent characteristic parameters.As turbulence has been decomposed into series of components in different frequency bands using the method based on wavelet analysis,it is convenient to get turbulent characteristic parameters such as turbulent intensity,turbulent energy spectra in time domain and turbulent scales for every component etc.Behaviors of turbulent integral time scales have also been studied,and results indicate that turbulent integral time scales, which are dependent on turbulent frequencies and energy percentage distribution in every frequency band, represent the expectation of life for all turbulent eddies.