动静干涉下压气机叶轮气动激励与振动分析

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.