单-厚盘转子过两阶临界转速的瞬态振动分析

航空发动机特殊的鼓式压气机结构可简化为径向转动惯量大于轴向转动惯量的厚盘转子系统,其做正进动时存在两个固有频率.计算了单-厚盘转子分别以定角加速度和定功率过两阶临界转速时对不平衡激振力的瞬态响应,其中定功率厚盘转子还与外界能源发生非线性耦合.结果发现,单-厚盘转子的低阶振型为轴的弯曲,高阶振型为盘的偏摆,其中高阶模态是厚盘转子特有模态;过临界转速时瞬态振动由转子的自由振动和强迫振动合成;当功率不足够提供转子通过临界转速时,出现外界能源与转子系统的能量耦合,造成瞬态振动急剧增大而"失速". 

Analysis of transient vibration of single-thick-disk rotor crossing two orders of critical speeds

The special structure of drum type compressor of aero-engine, which can be simplified as a thick-disk rotor system whose radial moment of inertia is greater than the axial one, has two inherent frequencies when whirling forward. Transient response to unbalance exciting force of single, thick-disk rotor crossing two orders of critical speeds in constant angular acceleration and constant working power was calculated respectively, and the nonlinear coupling between the thick-disk rotor and energy occurred at the latter. The results show that the low order vibration shape of single, thick-disk rotor is shaft's bend, the higher one disk's inclination, wherein the higher order mode is unique feature of thick-disk rotor; when rotor crosses the critical speed, its transient vibration is composed of free vibration and forced vibration; when the power is not enough to provide the rotor crossing critical speeds, the coupling between external energy and the rotor system will appear, resulting in a sharp increasing stall phenomenon.