摘要
通过小波变换对信号进行多尺度细化分析,解决了傅里叶变换不能解决的许多问题．从分析噪声和信号本身奇异点的区别入手,利用小波在时频两域突出信号局部特征能力的重要性质,即噪声信号小波变换的极大值随尺度的加大而显著减少的特点,对撞击流反应器撞击区压力波动信号进行处理分析．分析结果表明:小波变换可以较好地去除信号中的噪声;通过消噪后信号的功率谱可知,撞击流压力波动信号具有自相似的分形特征,与前期的实验研究相吻合．
By means of the fractionated multi resolution analysis of the signals with wavelet transform, many problems can be solved, which can not be solved by Fourier transform. From the differences between singular points of noise and signal, and the important features of wavelet transform in highlighting the local profiles of signals both in time-frequency domains, i.e., the fact that the maximum of the noise wavelet transform reduces dramatically with the increase of the scale, the pressure fluctuation is analyzed. The results show that the wavelet transform is a good way to eliminate noise; and by the power profiles of de-noised signals, the pressure fluctuation shows a fractal construction, as revealed in the previous study.
出处
《力学与实践》
CSCD
北大核心
2006年第2期33-36,共4页
Mechanics in Engineering
关键词
小波变换
撞击流
压力波动
信号分析
wavelet transforms, impinging stream, pressure fluctuation, signal analyzing
