The Numerical Investigation On The Form Of Blade Water Film And The Performance Of Rain Ingestion Process Of A Compressor

Compressor is one of the core components of the aeroengine, when the aircraft in the severe weather conditions, especially in engine swallowed larger rainfall, it may result in flameout, thrust reduce or even shutdown of the engine, causing accidents, consequences be unbearable to contemplate. Therefore, investigation of the engine performance in inclement weather conditions and water film formation on the compressor blades are necessary, so as to reduce the probability of accidents may be in flight, it has important significance for national security. But in the public published articles, there are few articles about the influence on the bad weather to the content of the performance of the engine parts.The progress which rain is ingested into an engine is a moment between rain and air two phase flow problem of complex momentum, heat and mass exchange. The impacts of water ingestion compressor are aerodynamic, mechanical and thermodynamic. In view of above problems, this paper does research on the influence of water film and the change of the water film on the air flow in the compressor is studied based on CFX with NASA Stage35. The main research contents are as follows:1. The motion analysis, heat and mass transfer analysis of the rain drop after entering the compressor are carried out. According to the interaction between the rain and the wall in the air flow, the droplet-wall interaction model and secondary breakup model are established. The heat transfer model of water droplet is selected for the two-way coupling process of discrete and continuous phases. Based on the model, the numerical experiments are carried out different conditions, combined with the actual weather conditions select the typical injection velocity and diameter to study the influence on the compressor performance comparison of different rain conditions. Research results show that the rotating stall boundary move to right and the chocking boundary move to left, leading to reduced the stabile margin, making stability decrease and the flow field worse.2. As the effect of mechanical effects, the calculation method of compressor torque and efficiency after the rain is developed, which lays a theoretical foundation for the study of the effect of the swallowing rain on the performance of the compressor. Research shows that the rain will consume more axial power, resulting in a substantial decline in the efficiency of the compressor.3. The formation of water film and the effect of water film on the flow field were studied under different conditions. Unsteady research use Wall-Film model with steady result as the initial value, compares the differences between the different rain conditions of water films, as well as the effects on the aerodynamic effect of impact. The results show that the water film is mainly formed on the pressure surface,the water film can achieve a dynamic stabilization process,and the thickness difference between the adjacent water film region will affect the flow deflection.