基于 POD 方法的对转压气机叶顶非定常流场分析

In order to investigate the unsteady flow characteristics and its flow mechanism in a counter-rotating compressor，a two-stage counter-rotating compressor was used as the research object，and the tip unsteady flow field analysis was carried out under the near-stall condition of the counter-rotating compressor based on the unsteady numerical simulation method in combination with the proper orthogonal decomposition (POD) method. The results showed that 1BPF (blade passing frequency) under near-stall conditions was taken as the dominant frequency of tip unsteady flow field in the upstream rotor，and its dominant structure was mainly caused by the influence of downstream potential flow and the impact of leakage flow and secondary leakage flow from the adjacent blade tip. Moreover，the potential flow of the downstream rotor had a greater influence on the unsteady flow in rotor R1. In the tip flow field in rotor R2，the POD modes succeeded in capturing the dominant flow structure at the inlet passage of the blade leading edge caused by spillage from the leakage flow with a dominant frequency of 0.8BPF，which played a dominant role in the unsteady flow field of rotor R2. Similarly，rotor R2 was affected by the interference of the two rotor rows，with a dominant frequency of 1BPF. In addition，the tip flow field reconstructed by the POD modes further reflected the dominant flow structure of unsteady flow field.