Abstract: The time series of instantaneous velocity in the Kenics static mixer, 0.04 m in diameter and 1.25 in aspect ratio, were conducted with laser Doppler particle analyzer. The signal of velocity fluctuation were decomposed into signals of different frequency band including 0~12.5, 12.5~25.0, 25.0~37.5, 37.5~50.0, 50.0~62.5, 62.5~75 Hz and more than 75 Hz based on Fourier transform. The linear and nonlinear correlation characteristics of signal of different frequency band were evaluated with auto-correlation function and mutual information function, respectively. The experimental results indicate that the signals of more than 62.5 Hz in frequency have no linear correlation, and there are no nonlinear and linear correlation for the time series signal which is over 75 Hz in frequency.

Key words: Static mixer , Mutual information function , Correlation ,  Instantaneous velocity 

摘要： 利用激光多普勒粒子分析仪对直径为0 .04 m 长径比为1.25 的SK 型静态混合器瞬时流场进行测
量。基于傅立叶变换对采集的瞬时速度波动信号进行分解, 得到0 ～ 12 .5, 12.5 ～ 25.0 , 25 .0 ～ 37.5 , 37.5 ～ 50 .0,
50 .0～ 62.5, 62 .5 ～ 75 .0 Hz 和大于75 Hz 的时域信号。利用自相关函数和互信息函数研究各个频率段信号的线性
相关和非线性相关性。实验研究表明SK 型静态混合器速度瞬时波动信号中62.5 Hz 以上的信号线性无关, 75 Hz
以上的信号不存在非线性和线性相关性。

关键词: 静态混合器 , 互信息函数 , 相关性 , 瞬时速度