On the generation of low-frequency signals in a transitional boundary layer
平板边界层转捩过程中低频信号的产生

The fast Fourier transform(FFT) and wavelet transformation were used to process the experimental data in a transitional boundary layer.A low|frequency high|amplitude distribution was observed in the power spectrum.The experimental evidence shows that this distribution is related to the intermittent phenomena in a fluid.Therefore,it responses to an intermittent data structure instead of a real physical one.