多 级 压 气 机 转 子 负 荷 系 数 对 叶 片非 同 步 振 动 的 影 响

Through theoretical computation，analysis and experimental research，this paper elucidates the Non-Synchronous Vibration（NSV）phenomenon of rotor blades caused by the Variable Stator Vanes（VSV）which are unexpectedly closed from design point in a core engine test. To reveal the underlying mechanism，three-dimensional full-annulus unsteady numerical simulation is initially performed on the first 1. 5-stage compressor where blade vibration is observed. The numerical results show evident flow separation at the rotor blade tip as the installation angle of the first-stage stator blade is closed from 2° to 6°，along with the progressively increase of stage loading of the first-stage rotor. Pressure fluctuation peaks are generated at non-integer multiples of rotational frequency by the unsteady vortex shedding，which is recognized as the characteristic of Rotating Instability（RI）. Further，the dependence of the occurrence of NSV induced by RI on the stage loading is systematically calculated and experimentally investigated on a 6-stage transonic compressor. Two-dimensional through-flow simulations are performed to estimate the change in the stage loading of the first-stage rotor with rotational speed under different Variable Inlet Guide Vanes/Variable Stator Vanes （VIGV/VSV）angles. Through a 6-stage compressor test，the analysis on the spectra of strain and pressure fluctuations indicates that NSV is excited on the first-stage rotor by RI when the first-stage stator is adjusted to -8°，which increases the stage loading of the first-stage rotor. The NSV is also observed when the first-stage stator and the second-stage stator are adjusted to -4° and -3. 6°，simultaneously. The present results clarify that besides large radial tip clearance，the closing angle of VIGV/VSV can also form high loads at the rotor blade tip，leading to flow instability in the blade tip region and then inducing RI. The findings of this research are of significant guidance to the design of a multistage compressor.