转静干涉对转子叶片颤振特性的影响

在不同气动工况、不同几何模型下,采用自行开发程序对全环多排的高压压气机进行了流固耦合数值模拟,分析了进口导流叶片(IGV,以下简称导叶)对转子叶片颤振稳定性的影响。通过对气动弹性标准算例4的数值模拟验证了程序在颤振领域的有效性。针对导叶-转子模型和单转子模型,考察了近堵塞点、近设计点和近失速点3个工况下,节径变化对叶片颤振稳定性的影响,给出了气动弹性最不稳定状态对应的叶片振动形式。通过对比发现,导叶作用随工况而异,近堵塞点导叶使得转子1阶弯曲模态气动阻尼提高130.63%。研究表明:导叶引起的非定常压力波反射增强了转子叶片的非定常压力扰动幅值,使得弯曲振型的颤振稳定性增强。基于单转子模型的颤振分析给出了不准确的气动阻尼值。

Influence of rotor-stator interaction on rotor blade flutter characteristics

A full-annulus multi-row coupled fluid-structure simulation on a certain high pressure compressor was conducted by an in-house program to analyze the influence of inlet guide vane (IGV) on rotor blade flutter stability in different operation conditions and geometry models. The effectiveness of the program in the field of turbomachinery flutter was verified by numerically simulating the aeroelastic standard configuration 4 for the IGV-rotor model and isolated rotor model respectively, detailed fluid-structure interaction analyses were performed at near choked, near design and near stall operation points to assess the effect of nodal diameter on the flutter stability. The least unstable vibration form of blade can be presented. By the comparison of the results, the influence of IGV varies with the operation conditions. At the near choked point, the rotor aerodynamic damping of the first bending mode increases by 130.63% via the IGV. The results indicate that the existence of the guide vane causes the unsteady pressure wave reflection, which can enhance the unsteady oscillating pressure amplitudes on the rotor blade surface and improve the flutter stability of the bending mode. Flutter analyses based on isolated rotor model will give inaccurate aerodynamic damping values.