非线性转子-密封系统动力学行为演变机理研究

Study on the mechanism and transformation of the dynamic behavior in a nonlinear rotor-seal system

旋转机械广泛应用于民用、航空、航天和航海等各个领域,其稳定的动力学行为是保证工程机械安全运行的前提。本文主要针对转子-密封系统丰富的非线性动力学行为,利用非线性动力学等理论分析了转子-密封系统发生Hopf分岔和1:2亚谐共振等动力学行为的产生条件和机理,进一步给出了非线性转子-密封系统由自激振动引发亚谐共振的动力学行为演变机理,并通过理论分析,阐明了转子-密封系统的气流阻尼和刚度等动力学参数对系统动力学稳定性的影响规律,同时也利用数值计算验证了分析结果。其理论分析结果对实际工程振动分析和结构设计具有一定的理论指导意义。

Rotating machinery is widely used in civilian, aviation, aerospace, navigation, and other fields, and the stability behavior of the system dynamics is a prerequisite guaranteeing safe operation. In this paper, by using non-linear dynamics theories, complicated transformation of the dynamic behaviors, Hopf bifurcation and 1︰2 sub-har-monic resonance, was investigated on a rotor-seal system, and the conditions and mechanism of the dynamic behav-ior were obtained. Furthermore, the evolution of subharmonic resonance dynamics in the nonlinear rotor-seal system caused by self-excited vibration was analyzed. Based on the theoretical analysis, it is observed that the damping and stiffness parameters of the nonlinear rotor-seal system affect its system stability dynamics. Finally, numerical calcu-lation verifies the results from the theoretical analysis. It is significant that the results of the the oretical analysis can explain the vibration behavior of the system and guide the structural design of the system in practical engineering.