The instability condition of aeroengine was studied in light of chaos and fractal theories

the chaotic character exponents of aeroengine in the process of entering instability condition were calculated.First

the pressure signal was denoised with wavelet method

and then the phase space of the engine was reconstructed.The method to calculate correlation integral was improved

then

the Lyapunov exponents and correlation dimension were calculated with the method of sliding window.The results show that the chaos exponents changed markedly as the condition of aero-engine varies

as a consequence

the chaos exponents can be used to identify the aero-engine condition and as a new method to study the dynamic characteristics.