轴流压气机叶尖三维非定常流动的本征正交分解

POD Analysis on the Unsteady Flow Field at the Blade Tip Region in Axial Compressor Rotor

  • 摘要: 为进一步认识跨声速轴流压气机叶尖流场的非定常流动特征,文章针对NASA Rotor 35的非定常数值计算结果,通过本征正交分解法(Proper Orthogonal Composition,POD)对近失速工况下的叶尖非定常流动进行分析。结果表明:本征正交分解法可以将叶尖非定常流动按能量高低进行模态分解。并通过分析各模态系数频谱特性,捕捉到了叶尖流场非定常流动的波动频率及对应模态在叶片前缘沿周向移动的大尺度扰动结构。该方法使用叶尖流场波动频率对应模态进行流场重构,揭示了流场非稳定流动的特征结构。

     

    Abstract: In order to further investigate the unsteady characteristics of the transonic axial compressor blade tip flow field, the unsteady simulation of the NASA Rotor 35 is carried out to get the performance in different mass flows. Based on the simulation results, the blade tip flow field is decomposed by using proper orthogonal decomposition (POD) method. The results indicate that POD method can decompose the blade tip unsteady flow according to their energetic values and it can capture the fluctuation frequency of the blade tip unsteady flow field, the corresponding modes show large scale disturbance characteristic structure in the blade leading edge, moving along the circumferential direction. By reconstructing the flow field, the disturbance feature structure propagating along the circumference is reproduced visually.

     

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