高负荷压气机旋转不稳定诱发转子叶片非同步振动的实验研究

Experimental Research on Rotor Blade Non-Synchronous Vibrations Induced by Rotating Instability of High Load Compressor

关键词:  高负荷压气机  旋转不稳定  转子叶片  非同步振动  压力脉动

Key words:  Highly-loaded compressor  Rotating instability  Rotor blade  Non-synchronous vibrations  Pressure fluctuation

摘要:

为揭示高负荷压气机旋转不稳定诱发转子叶片高振幅值非同步振动的发展过程及其产生机理，本文从实验角度出发，详细揭示了一种由旋转不稳定涡激发转子叶片非同步振动瞬态过程中流体主动作用至被动响应的变化趋势。研究结果表明，在叶片振动触发前，第一级转子叶尖分离涡扰动已存在，但其频率与叶片固有频率未耦合。随级负荷进一步升高，分离涡频率小幅波动，诱发其与叶片一阶固有频率耦合，激发转子叶片高振幅值振动。气流扰动周向模态数由流体主动作用时的高模态发展为被动响应时的低模态。

Abstract:

In order to reveal the development process and the mechanism of the high amplitude non-synchronous vibration of the rotor blade induced by rotating instability （RI） of high load compressor， from the perspective of experiment， this paper reveals the transient process of the RI-excited non-synchronous blade vibration from the fluid active action to the passive reaction. The results show that the tip separation vortex of the first-stage rotor has already existed before the blade vibration， however， its frequency is not coupled with the blade natural frequency. As the aerodynamic load increases， the vortex frequency fluctuates within a finite extent， which induced the coupling of the vortex frequency and the blade first natural frequency， so that the rotor blade vibrates at a high amplitude values. The circumferential mode number develops from a high mode when fluid is actively acting to a low mode when the fluid is passive response.