Windage Characteristics Investigate of Centrifugal Impeller Rear Cavity

This study aims to investigate the windage characteristics of the centrifugal impeller rear cavity using experimental and numerical simulation methods. The effects of various flow parameters such as flow coefficient and rotating Reynolds number, as well as structural parameters such as air inlet clearance, air outlet radius, rotor–stator clearance, and the presence of bolts, were investigated to determine the torque coefficient characteristics of the centrifugal impeller rear cavity rotor under different operation conditions and structures. The findings indicate that the torque coefficient of the rotor increases with the increase of flow coefficient, and decreases with the increase of rotating Reynolds number. Among the structural parameters, the torque coefficient decreases with the increase of air inlet clearance. The influence of air outlet radius on the overall windage torque of the rotor is not significant. The torque coefficient shows an increasing trend with the decrease of rotor–stator clearance until the critical clearance is reached, after which it decreases. The addition of bolts to the stator increases the torque coefficient by approximately 70%.