| As one of the important components of aircraft engines, the occurrence of phenomenon such as surge and stall for axial compressor will lead to engine failure or even crash due to the unstable conditions of the fluid, resulting in a significant impact on the safety of aircraft. Therefore, analysis of its causes and threshold for stall and surge has a great significance for aero-engine compressor's troubleshooting.In this paper, we use the nature of independence between potential power system and random noise to reduce the level of noise in order to obtain mapping equations of the potential power system, and then we can further obtain the spectrum estimation of Lyapunov exponent; According to the feature that the largest Lyapunov exponent does not vary with changes of embedding dimension in the phase space, we can calculate the largest Lyapunov exponent of chaotic dynamical systems from a sequence of time and then we can determine the threshold of chaotic dynamical systems for our future judgment; we get a summarize for the domestic and foreign status of the existing research of compressor's stall and surge, then we do a deep analysis from various factors; we use the Solidworks to build a three-dimensional model for axial compressor Rotor37 and Stage 37, we take advantage of Ansys ICEM to mesh the model. Finally, we utilize CFX to do the modeling and simulation of the flow field analysis for stall and surge, at the same time, specific points where occur the phenomenon of surge and stall are monitored, we can extract the corresponding velocity-time curve by changing the mass flow rate and rotor speed, we use the method of analysis for chaotic dynamical systems so that we can calculate the largest Lyapunov exponent, determine the threshold. At last, the results will be compared with experimental data, from the data comparison, it shows that the largest Lyapunov exponent has a guiding significance for us to determine the threshold of compressor's stall and surge. |
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