高 原 工 况 压 气 机 叶 轮 振 动 失 效 特 征 分 析

A turbocharged engine centrifugal compressor impeller simulation model was established to analyze the reasons for vibration failure under plateau conditions. The unsteady computational fluid dynamics method was used to study the time domain and frequency domain characteristics of aerodynamic excitation on the impeller under plateau resonance conditions. Based on one-way fluid-solid coupling，transient dynamics and harmonic response methods were used to research the dynamic characteristics of the resonant impeller under the action of aerodynamic excitation. Finally，the reason for impeller vibration failure in plateau conditions was obtained. The results show that the fourth-order aerodynamic excitation affects the resonance of the impeller under plateau conditions，which is caused by the dynamic and static interferences between the blade and the volute tongue. The blade tip clearance leakage flow increases the pressure fluctuation at 20% chord length of the suction surface. Impeller resonance under aerodynamic excitation leads to an increase in vibration stress at the leading edge of the blade. The vibration stress amplitude reaches 101. 5 MPa at the blade’s leading edge，which is consistent with the actual blade vibration failure.