Acoustic signal processing method for water turbine impacted by sand-containing water flow

The invention relates to an acoustic signal processing method for a water turbine impacted by sand-containing water flow, and belongs to the technical field of water turbine state monitoring. Sound signals at the runner blades of the hydraulic turbine set under different working conditions are collected; performing ICEEMDAN decomposition on the original sound signal to obtain a series of intrinsic mode functions; calculating a correlation coefficient and a variance contribution rate of the IMF, and finding a minimum value point; dividing the IMF into a high-frequency noise component, a transition signal component and a useful signal component through a minimum value point; performing wavelet threshold de-noising on the transition signal component, and reconstructing the transition signal component and the useful signal component together to obtain a de-noised signal; fourier transform is carried out on the noise reduction signal to obtain a spectrogram; calculating sample entropy characteristic values of the