叶片丢失后发动机整机响应模拟试验与仿真

依据大涵道比涡扇发动机结构设计了叶片丢失试验台,开展了一系列模拟叶片丢失试验,并采用显式有限元方法进行了数值仿真,研究了发动机叶片丢失后整机结构响应与载荷传递规律。结果表明:丢失叶片与机匣存在叶尖与叶身两次撞击,对应的加速度曲线存在两个响应峰值；转子转速越高,加速度响应幅值越大。叶片飞断后转子不平衡载荷传递路径为前轴承支承-中轴承支承-中介支板-机匣结构；叶片撞击机匣导致的冲击载荷则由风扇机匣向后传递,最终传给吊装结构；发动机承受的载荷是由不平衡和冲击影响耦合得到,其中冲击载荷为主要部分。该研究为掌握真实发动机叶片丢失下整机响应规律提供了试验模拟方法与数值仿真分析工具。 

Simulated test and numerical simulation of aero engine whole engine response during blade out event

Blade off test rig was designed according to the structures of typical big bypass ratio turbofan engine structure. A series of simulated blade off tests and numerical simulation using the explicit finite element method were carried out to investigate the whole engine response and load transmitting path. It was found that the released blade impacted the casing with its tip and body respectively, whilst two crests existed in the acceleration curves. The amplitude of acceleration increased with the blade release speed. The rotor unbalance load transmitted from the front bearing, to medium bearing, intermediate supporting plate, and finally the casing. The impact load caused by the released blade transmitted backward from the fan casing, and finally to the mounting structure. The impact load played the major role in engine load due to blade out event with respect to rotor unbalance load. The investigation can provide the modeling testing approach and numerical analysis tool for the study of whole engine response of aero engine under blade out event condition.