POD和DMD方法分析不同间隙压气机旋转不稳定性特性

Analysis of rotating instability characteristics in compressor with different tipclearances by POD and DMD methods

对一台单级低速轴流压气机旋转不稳定性(RI)进行分析。在前期的旋转不稳定性特性、流场成因和不同间隙影响的研究基础上,进一步基于全通道数值模拟,采用两种流场降阶方法分析不同叶顶间隙条件下旋转不稳定性各阶模态对应的流场成分、模态能量占比和稳定性等特性。计算结果表明,前几阶模态能量占比大,对流场起主要贡献,并且稳定性相对较强。随着间隙的减小,旋转不稳定性的能量占比和稳定性下降,各阶的叶片转动成为流场的主要成分。

Rotating instability(RI)characteristics of a single-stage low-speed compressor were analyzed.Based on the preliminary results of RI characteristics,flow cause and influence with different tip clearances and full passage numerical simulation,two flow field decomposition methods were applied to obtain the flow components,energy proportion and stability of RI modes.The computation results reveal that the first several modes account for a large proportion of energy,make major contributions to the flow field and have stronger stability.With the decrease of tip clearance,the energy and stability of RI modes decrease gradually,while blade rotating and its harmonics become the main components in macro flow field.