关键词: 离心压气机;分流叶片;周向位置;叶片长度;流场特性

Abstract: To reveal the effects of splitter blade length and circumferential position on performance of high pressure ratio centrifugal compressor， numerical method was used to analyze performance and flow structures of the compressor with typical splitter blade lengths and circumferential positions. Based on the detailed analysis of flow fields in the compressor， the relationships between compressor flow structures and parameters of splitter blade length and circumferential position were established. Results indicate that both length and circumferential position should be taken into consideration for the optimization design of splitter blade. The optimal compressor stage performance can be achieved with the splitter blade case of 60% length and 60% circumferential position， which improves the pressure ratio and efficiency by 3.2% and 1.0% than the design values， respectively. The mechanisms of splitter blade improving compressor performance are the split effect of splitter blade on the main blade leakage vortex， and the ejection effect of the high speed and low pressure airflow near splitter blade suction surface on leakage vortex. In the process of splitter blade optimization， the blade length and circumferential position ought to be reasonably selected to realize the split and ejection effects of splitter blade on the main blade leakage vortex. In the meantime， overlong splitter blade should be avoided， which may cause significant tip secondary leakage and high Mach region around the leading edge of splitter blade.

Key words: Centrifugal compressor;Splitter blade;Circumferential position;Blade length;Flow field characteristics