含裂纹的涡轮增压器转子系统动力特性研究

Study on the Dynamic Characteristics of Turbocharger Rotor System with a Crack

为获得裂纹对涡轮增压器转子系统动力特性的影响,将其简化为涡轮盘根部含开斜裂纹的双盘悬臂转子,并建立了该系统动力学模型与微分方程。利用四阶Runge-Kutta法进行求解,研究有无裂纹两种情况下系统的动力学行为。结果表明,在所考虑的参数范围内,无裂纹系统在高速时出现拟周期运动。而裂纹系统在1/3Ωc、2/3Ωc附近有3倍周期、拟周期等更丰富的非线性行为,且裂纹减弱了高速时油膜力的作用。结论可为裂纹故障诊断提供理论参考。

Abstract. To obtain the influence of crack on the turbocharger rotor system, the dynamic model and differential equation were built by simplifying the turbocharger as a dual-overhung rotor with open slant crack at tile shaft of turbine disk, and Runge-Kutta method was applied to solve the equation. The results show that with the parameters considered, quasi-periodic motions appear at the higher speed in the system without crack while rich nonlinear dynamic behaviors such as period-three motions and quasi-periodic motions appear at the rotor speed region 1/3Ωc and 2/3Ωc in tile system with crack. Besides, the crack weakens the oil-fihn tbrce. The conclusion is helpful for crack fault diagnosis of turbocharger.