Behavior Analysis of Water Droplets in Wake Flow of a Transonic Cascade

摘要

The compression process in an axial compressor with water injection is a complex two-phase flow involving many changes of water existing forms. Boundary conditions close to the real ones of water droplets on compressor blade are extremely important for numerical simulation. Water droplet impinging and stick to surfaces of compressor rotors or stators will form into water film, and then shed off from the trailing edge of the blade. For a rotor with high rotating speed and a stationary stator, the shedding water film from the trailing edge may experience different aerodynamic breakups study of which is very import for the application of water injection technique to compressor. In this paper, comparison and analysis on breaking up of big droplets in the wakes of rotor and stator are carried out through designing appropriate numerical experiments. In order to obtain the comparable wake flows for rotor and stator separately which are elementary for this study, a transonic rotor, NASA rotor 37, was chosen for the present study to produce nearly uniform wake flows of rotor and stator. Research found that movement and breakup of big droplets in wake flows is entirely different for rotor and stator, and this discovery is of great significance.