Aeroelastic vibration problems are commonly found in modern compressors operating in off-design conditions. Large amplitude vibration could lead to high cycle fatigue (HCF) of blade and usually occurs in front stages of axial compressors. In this study, the influence of tip gap size on aeroelastic stability is analyzed in a 1.5 stage compressor with an in-house fluid-structure interaction code. A three-dimensional unstructured finite-volume compressible flow solver is applied in the fluid domain and a structure dynamic solver with the modal superimposition method for blade motion is used in the structure domain. Rotor tip clearances of 1%, 2% and 3% of tip axial chord at maximum rotor loading conditions at off-design speeds are analyzed for aeroelastic stability. The tip leakage flow and vortex structure can be seen near the blade tip region at a larger tip gap size. The aeroelastic stability of rotor blade at different tip gap sizes is mainly influenced by the 1st torsion mode, and the variation of aerodynamic damping is not monotonous. The intensity of the tip vortex and shock wave are the key factors affecting the aeroelastic stability of rotor when tip gap size increases.

在非设计条件下运行的现代压缩机中通常会发现气动弹性振动问题。大振幅振动可能导致叶片的高循环疲劳（HCF），通常发生在轴流压缩机的前级。在这项研究中，在内部流体-结构相互作用代码的1.5级压缩机中，分析了叶尖间隙尺寸对气动弹性稳定性的影响。在流体域中使用了三维非结构化有限体积可压缩流动求解器，在结构域中使用了采用模态叠加方法进行叶片运动的结构动力求解器。在非设计速度下，在最大转子负载条件下，分析了叶尖轴向弦的1％，2％和3％的叶尖间隙的气动弹性稳定性。可以在叶片尖端区域附近以较大的尖端间隙尺寸看到尖端泄漏流和涡流结构。转子叶片在不同叶尖间隙尺寸下的气动弹性稳定性主要受第一扭转模式的影响，并且气动阻尼的变化不是单调的。当叶尖间隙尺寸增加时，叶尖涡流和冲击波的强度是影响转子气动弹性稳定性的关键因素。