Simulation on Expanding Steady Working Range of Centrifugal Compressor by Self-Recirculation Casing Treatment

Abstract

Numerical simulation method is adopted to simulate and research Self-Recirculation Casing Treatment (SRCT) on expanding the scope of steady work of high-pressure-ratio centrifugal compressor, and increase the compressor surge margin. Contrast the influences which are caused by structure sizes of the SRCT on the performance of compressor. The results showed that SRCT make the compressor stable operating range average broaden more than 13% on all kinds of speed, the surge margin increased by 11% at most. During the structure sizes, the distance between the bleed slot and the splitter blade has the largest affect on the performance of centrifugal compressor, followed by the bleed slot width, others have less affect. SRCT make the distribution of the compressor impeller inlet relative Mach number is more uniform, weaken the phenomenon of blade leading edge local high Mach number. It is also decrease the blade inlet positive incidence, inhibit separation of the blade surface boundary layer.