Application of Lyapunov exponent spectrum in pressure fluctuation of draft tube

The Lyapunov exponent spectrum is firstly applied in the analysis of pressure fluctuation of draft tube and calculated based on the time series of vibration in experiments for different situations. Results shows that the Lyapunov exponent spectrum varies with the setting of guide vane, So the Lyapunov exponent spectrum can be used to judge the pressure fluctuation of draft tube so as to timely adjust the setting of the guide vanes to reduce the damage caused by the vibration.