小展弦比压气机转子叶片颤振研究

针对小展弦比压气机转子叶片特点,在能量法计算基础上提出了两种颤振评判方法,即首先利用结构动力学分析结果对叶片频率分离度、振型和共振进行分析,判断某压气机小展弦比转子叶片存在高阶耦合颤振的可能;然后将结构动力学得到的振动位移插值到气动网格上,进行三维非定常黏性流场计算,得到非定常气动功,判断叶片是否存在失速颤振的可能.最后综合利用两部分分析结果和试验及断口分析情况,综合给出该小展弦比压气机叶片因失速颤振和耦合颤振共同作用,导致叶片在短时间内出现了裂纹. 

Flutter investigation of small aspect ratio compressor rotor blade

For the characteristics of small aspect ratio compressor rotor blade, two judgement methods on the basis of energy method were presented. The analysis results of structure dynamics were employed to analyze the rotor frequency dispersion, vibration mode and resonance vibration, while the possibility of high mode coupled flutter was estimated. Then the vibration displacements from structure dynamics into aerodynamic mesh were applied to calculate three dimensional nonsteady viscous filed to get unsteady aerodynamic work, estimating the possibility of stall flutter. Finally, considering two analysis results as well as the test results and fracture analysis, cracks appeared in small aspect ratio compressor rotor blade within a short time due to the combined effects of stall flutter and coupled flutter.