Development of end-bent/swept blade for multistage axial compressors

摘要

The endbent/swept (EBS) blades have been developed to improve the endwall boundary layer flows in middle stages of axial compressors. They have three distinctive features: the leading-edge sweep near the tip and hub to activate the annulusboundary layer flows, the leading-edge bend near the tip and hub to meet a preferable inlet flow condition, and the same exit metal angle of blade evaluated by a conventional vortex design method.The EBS and baseline blades were designed for both of the rotor and stator, and the stage performance testing was conducted in every combination of the rotor and stator in a low speed compressor test rig. The results showed that the maximum stageefficiency of the EBS rotor was higher than the baseline rotor and the considerable increase in surge margin was obtained by using the EBS rotor and stator. The effects of the EBS rotor and stator on the endwall boundary layer flows were clarified by theflow measurements downstream of the rotor and stator with a hot-wire and 5 hole-probe.