Investigation of endwall treatment and shock control in a five-stage axial compressor

Abstract

Multistage axial compressor is one of the key components in aero engines and gas turbines. In this paper, a five-stage axial compressor was studied to improve the efficiency. First, the loss analyses of the datum compressor were performed. The results showed that front rotors and rear stators have higher loss. Based on the loss analyses, the corresponding flow controls were introduced. The endwall treatment was performed with the rear stators, S3, S4, and S5, by end-bow, which changed the blade loading and reduced the loss due to endwall boundary layer. The efficiency of the datum compressor was increased by 0.5%. Based on the improved redesign of rear stators, shock control was introduced to front rotors, R1 and R2, characterized by sweep, which changed the shock structure and decreased the shock-induced loss and shock-tip leakage interaction. Coupled between endwall treatment and shock control, compared to the datum compressor, the efficiency, peak pressure ratio, and choked mass flow were increased by 1.1%, 1.1%, and 1.2%, respectively. At off-design speeds, the performances were also improved, which implies the flow controls for design speed remain effective in a range of off-design speeds. The reliability of the redesigned compressor was validated by stress and mode analyses.