Experimental Study on Aerodynamic Performance and Casing Treatment of First Stage Centrifugal Compressor for 1000shp-class Turboshaft Engine

Korea Aerospace Research Institute (KARI), in cooperation with Hanwha Aerospace (HAS), has developed a two-stage centrifugal compressor in a gas generator for a 1,000-shp turboshaft engine. A bleed-type casing treatment was applied to the shroud casing of the first-stage impeller in order to improve the surge margin in the low-speed range of the compressor. In this study, before carrying out the evaluation of the aerodynamic performance of the overall 2-stage compressor, a performance test was conducted on the upstream 1-stage compressor to investigate the effect of bleeding. A bleed slot with a width of 2 mm was applied around the leading edge tip of the splitter blade of the impeller for casing treatment, and the change in aerodynamic performance and surge margin was examined with respect to the position of the bleed slot compared to the reference model.