Influence of rotor–stator component partition structure on the aerodynamic performance of centrifugal compressors

The partition structure (PS) between the impeller and stationary blade of a centrifugal compressor considerably influences a compressor's performance. Based on computational fluid dynamics, this study constructed a coupling calculation model for the main flow, wheel cover, wheel disk side partition clearance, and sealing structure. Furthermore, we examined the influence that different PS shapes (i.e. circular arc, trapezoidal, and rectangular) and radial clearances (2, 4, and 6 mm) at the entrance of the cavity between the rotor and stator components have on the aerodynamic performance and loss mechanism of the centrifugal compressor using a numerical method. The influence that the PS has on the transition zone between the impeller outlet and stator inlet sections was analysed in detail. According to the results, when the PS was in a circular arc form, with a clearance of 2 mm, it achieved the highest efficiency, which increased the efficiency of the original model by 0.99% and the total pressure ratio by 1.23%. Moreover, an examination of the main flow interaction provided an enhanced insight into the microflow phenomenon in centrifugal compressors.