Numerical Study of the Flow and Characteristics in a Multistage Compressor Based on Different Spatial Distribution Forms of Rainwater

An aeroengine must be able to work safely under severe weather such as rainy weather. The intake of excessive rainwater into the aeroengine can induce stall and surge in the compressor, and the performance changes of the compressor after water ingestion directly affect the work reliability of the aeroengine. The form of spatial distribution of rainwater at the compressor inlet is one of the important factors causing its performance changes, and the characteristic distribution of water droplets may lead to the occurrence of flow distortions at the inlet and inside the compressor. Therefore, this paper takes the water droplet distribution at the inlet of the compressor as the starting point and uses the full-flow CFD numerical method to investigate the changes of internal flow and characteristics of a multistage compressor under typical water ingestion conditions. The water droplet distribution index (Kθ), which describes the inhomogeneous distribution of water droplets along the circumferential direction of the compressor inlet, is defined in this study. The results show that the larger the water droplet distribution index is, the more obvious the performance degradation will be, and the narrower its stable working range will be. Additionally, the results also showed that the full inlet nonuniform and localized water ingestion can lead to flow field distortion characteristics inside the compressor.