Influence study of un-equilibrium inlet condition to flow loss characteristic of a double-sided centrifugal impeller

The double-sided centrifugal impeller is a promising configure in internal engine tur-bocharging area. In this application, the double-sided impeller is suffered un-equilibrium inlet condition. It is necessary to understand un-equilibrium inlet condition influence on the double-sided impeller performance. Numerical simulation was employed to predict the diffuser flow loss. The results show that, the double-sided impeller performance, especially in near stall operation condition, is greatly affected by the inlet condition difference. With the inlet condition difference increase, both the impeller performance and stall margin decrease. Moreover, the main flow loss in diffuser is the exhaust mixing loss of double sided impeller under the large mass flow condition; On the small mass flow condition, the wall separating vortex loss is more obvious than the exhaust mixing loss in the diffuser.