航空发动机双转子系统高/低压涡轮碰摩振动分析

针对航空发动机碰摩问题,考虑高压涡轮与低压涡轮碰摩,建立了五点支承的航空发动机双转子系统动力学模型.碰摩力模型采用Lankarani-Nikravesh滞回力模型.利用龙格-库塔法进行数值计算,并研究了双转子系统的频谱特性、幅频特性.最后,基于双转子实验台,部分验证了数值计算结果.结果表明:(1)双转子系统碰摩会使系统...

Rub-impact vibration analysis of PH/LH turbines of aeroengine dual-rotor system

Considering rub-impact of high pressure(HP)and low pressure(LP)turbines of an aeroengine,a five-point supported aeroengine dual-rotor system’s dynamic model was established.Lankarani-Nikravesh hysteretic force model was taken as the rub-impact force model.Then Runge-Kutta method was used to do numerical calculation,and study spectral characteristics and amplitude-frequency ones of the dual-rotor system.Finally,based on a dual-rotor test platform,the numerical results were partly verified with tests.Results showedthat(1)rub-impact of the dual-rotor system can generate excitation frequencies and combined frequencies,and combined resonance appears;(2)rub-impact of HP turbine can cause reverse whirl and full annular rub,and rub-impact of LP turbine can suppress rub-impact of HP turbine,sowhen HP and LP turbines rub simultaneously,compared with rub-impact of HP turbine only,the rotating speed range for the system reverse whirl is narrower and vibration amplitude is lower;(3)in process of speed up and down,rub-impact can cause single or even multiple bi-stable phenomena in the dual-rotor system.