In recent years, vibration sources

In recent years, vibration sources nurtured in inner flows of the impeller pump have gained much attention, and it has been verified in some cases that static pressure fluctuations and pump vibration share typical frequencies .Most of these frequencies are harmonics of shaft frequency or blade passing frequency.The axial-flow pump is featured by unsteady flows between impeller blades and stator vanes. Although numerous efforts have been dedicated to the impeller–stator interaction in the axial-flow pump, a clear explanation of this subject is still sorely necessitated. This study is anticipated to provide a further insight into axial-flow pump performance, as well as inner flow characteristics in the pump with different combinations of impeller blades and stator vanes.Several studies confirmed the connection between flow characteristics and operation performance of the pump, but no robust explanation has been furnished so far . Since some factors such as mechanical loss and leakage loss were not taken into account in numerical simulation, the operation performance of the pump predicted numerically inevitably incorporated errors. Under such a circumstance, a performance test was carried out on the test platform in Shanghai Kaiquan Pump Group Co., Ltd. Through adjustments and regulation sperformed on the experimental system, the maximum uncertainties for measurements of pump head and pump efficiency were less than 1% and 1.8%， respectively. Both pump head and pump efficiency were measured for the three pumps with different vane numbers and the results are plotted in picture.