动静干涉下压气机叶轮气动激励与振动分析

为研究离心压气机叶轮的气动激励特征及激励作用下的振动特征，建立了单向瞬态流固耦合模型进行计算分析.利用模态分析确定了叶轮的共振工况，在此工况下进行单向瞬态流固耦合计算.讨论了叶轮与进气弯管和出口蜗壳发生动静干涉时，其表面非定常气动激励的时域与频域特征，并进一步讨论了叶轮在此气动激励下振动时的时域与频域特征.结果表明，叶轮共振时的主要振动分量是基频与共振频率处的振动分量，共振频率处较小的气动激励引发了较大的振动幅值；长叶片吸力面前缘等位置处动应力及离心应力较大，是疲劳失效危险点，叶轮易从此处萌生疲劳裂纹并发生疲劳断裂. 

Aerodynamic Excitation and Vibration Analysis of Centrifugal Compressor Impeller under Dynamic and Static Interference

In order to study the aerodynamic excitation characteristics and vibration characteristics of the centrifugal compressor impeller, a unidirectional transient fluid-structure coupling model was established for calculation and analysis.The modal analysis was used to determine the resonant working condition of the impeller.Under this working condition, the unidirectional transient fluid-structure coupling calculation was performed.The time and frequency domain characteristics of the unsteady aerodynamic excitation on the impeller surface were discussed, when the impeller interacts with the intake elbow and the outlet volute.The time and frequency domain features of the impeller vibration under this aerodynamic excitation were further discussed.The results show that the main vibration components of the impeller during resonance are the vibration components at the fundamental frequency and the resonance frequency, the smaller aerodynamic excitation at the resonance frequency can cause a larger vibration amplitude;The dynamic stress and centrifugal stress at the leading edge of the long blade suction surface are relatively larger, therefore it is a dangerous point of fatigue failure, and the impeller is prone to generate fatigue cracks and occur fatigue fractures from here.