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基于对小波变换的分析 ,确定了能较准确地反映信号振幅的相干结构波形重构公式 .采用Morlet小波能有效地重构出不受基波干扰的次谐波波形 .结合Morlet小波分辨率高的优点和正交小波正交性的优点 ,提出了实际含噪声信号中相干结构波形的重构公式 ,既可重构出次谐波的波形 ,又可排除高频噪声的干扰 .提出了基于小波分析的湍流中相干结构局部奇异性分析的研究方法 ,可以计算相干结构的结构指数 .用模拟信号和圆形湍流射流边界层内的实验数据对上述结论进行了验证 .
Based on the analysis of the wavelet transform, the waveform reconstruction formula of the coherent structure that can accurately reflect the signal amplitude is determined. The Morlet wavelet can effectively reconstruct the subharmonic waveform from the fundamental wave interference. Combining with Morlet wavelet high resolution And the advantages of orthogonal wavelet orthogonality, a reconstruction formula of the coherent structure waveform in the real noisy signal is proposed, which can not only reconstruct the subharmonic waveform but also eliminate the interference of high frequency noise. Wavelet analysis of turbulence in the local structure of the coherent structure of the singularity analysis method can calculate the structure index of the coherent structure.The simulation results and the experimental data of the circular turbulent jet boundary layer verify the above conclusion.