关键词: 多级压气机;壁面粗糙度;角区分离;尾迹掺混

Abstract: In order to investigate the effects of wall roughness on multistage compressor performance, three-dimension simulation software CFX was used to conduct preliminary research on the roughness of the blade and the end-wall respectively, as well as different quantity roughness of the blade surface. The results show that blade roughness has much more influence on performance than end-wall roughness. At different rotating speeds, the total pressure and isentropic efficiency usually decrease with increasing roughness, the faster the roughness increases, the faster the performance degradation will be. The roughness at the design speed has a greater influence on the compressor performance, when blade surface roughness increases to 50μm, the peak efficiency of the compressor decreases by 5.25%, the pressure ratio at the corresponding point decreases by 1.33%. The roughness of the former stage deteriorates the separation of the latter corners and the loss of the trails, which accounts for a larger proportion of the performance degradation of the compressor. The last-stage blade roughness has little effect on the separation zone, mainly due to the increase of the wake blending loss. Single-stage roughness has little effect on the compressor margin, while all-stage roughness increases the compressor margin, which is due to the fact that the flow drop caused by roughness at the near-stall point is greater than the blocking flow.

Key words: Multistage compressor;Wall roughness;Corner separation;Wake blending