发动机静子尾流激励对叶盘结构高阶共振可激性的研究

Research on excitability of the wake of stator in aero-engine to high order resonance of bladed-disk

针对航空发动机中转静干涉流场诱发的叶盘结构强迫响应问题,分析由导流叶片和动叶构成的转静干涉流场的尾流激励所激起的叶盘结构高阶共振的可能性和危险性.基于非定常转静干涉流场数值模拟结果,通过时域与空间傅里叶分析得到叶盘所受气动压力的频谱和空间波谱,同时定义投影于叶盘结构模态空间的激励(即模态力)为尾流激励的可激性,用于对叶盘结构共振响应强度的评估.研究结果表明:尾流激励对非主要共振点的可激性远远小于其对主要共振点的可激性;在发动机工作转速范围内允许那些模态位移场与激振力场的夹角较大(余角较小)的共振存在,即尾流激励可激性很小的高阶共振的存在是合理的.

Targeting the force severity of resonances induced by d vibration of bladed-disk in aero-engine, the impact of the flow-wake of stator was studied. On the basis of the nu- merieal simulation of unsteady stator-rotor interface flow, both frequency spectrum and spa- tial spectrum of aerodynamic pressure on the rotor surface were obtained respectively by fast Fourier transformation. Meanwhile, the excitability of wake was defined as the projection of aerodynamic pressure on the modal space, also called modal force, so as to evaluate the strength of resonant response of bladed disk. The analysis shows that the excitability of wake to a non-primary resonance is much less than a primary resonance. As a result, it is reasonable that in the operating speed region of aero-engine, the existence of high-order reso- nances with small complementary angle between aerodynamic force and modal displacement of bladed disk （small excitability）, should be accepted.