Numerical Investigations on Slip Characteristics and Slip Onset Position in High-Loaded Backswept Centrifugal Impellers

Abstract

This paper mainly investigates the effect of mass flow, blade turning and tip clearance size on the slip characteristics in the high-loaded backswept centrifugal impeller by numerical simulation. The numerical results show that the slip onset position mainly depends on the blade loading and the intensity of tip leakage flow. The mass-averaged slip onset position moves upstream but changes little with increased mass flow. The mass-averaged slip onset position is very close to the position of the peak value in the B2B blade loadings at the design condition. With increased exit blade angle, the mass-averaged slip onset position moves downstream and the mass-averaged slip factor increases. With increased tip clearance size, the mass-averaged slip onset position moves downstream first and then upstream. This study can supply some guidance to develop the slip onset position prediction model for high-loaded backswept centrifugal impellers.