Abstract: PIV technology and numerical simulations are employed to study the flow in centrifugal pump impellers with splitting vanes under different working states. Through experi- mental tests and numerical simulations, the flow fields in impellers are obtained for various working states. The results exhibit some basic flow characteristics in impellers: the asymmetry of flow in impellers; backflow occurs in the inlet suction side of long vanes; high speed region exists in the immediate region behind the shroud of splitting vanes; the outlet velocity profile is impr oved by splitting vanes; relative velocity increases evidently with the increase of flow rate. All these flow phenomena directly affect the performance of pumps.

Key words: Centrifugal pumps, Impellers, Numerical simulation, PIV technology, Splitting vanes