Abstract: The influence of adding splitter blades on the performance of a low-specific speed centrifugal pump is studied. The studied model is an IS 50-32-160 pump, whose impeller is designed with and without splitter blades. Velocity and pressure fields are computed by using steady Reynolds-averaged Navier-Stokes approach at different flow rates. The sliding mesh method is used to simulate the impeller-volute interaction. Based on the computation of moment, and combined with empirical formula, a design formula for splitters inlet diameter is given, which is suitable for the low-specific speed centrifugal pump. The flow morphology also shows that, when adding splitter blades to the impeller, the impeller periphery velocities and pressures become more homogeneous, which can reduce the pressure fluctuation at the area between impeller outlet and volute inlet. The performance parameters are evaluated at various flow rates, and the results show that, by adding splitters, the maximum efficiency moves to the larger flow rate, but not at the best efficiency point (BEP), and the operating range is extended. The influence of different blade number on the pump performance is summarized, and the reference number of blades is presented.

Key words: Blade number, Low-specific speed centrifugal pump, Pressure fluctuation, Splitter blade inlet diameter, Splitter blades, Cutting parameter optimization, Genetic algorithm, Machining stability, Objective function