Optimization study on a novel high-speed oil-free centrifugal water pump with hydrodynamic bearings

In aerospace fields and industrial sectors, high-speed centrifugal pumps are prevalent and in increasingly strict demand regarding characteristics such as the long life, small volume, light weight, and low noise. In this study, we present a novel high-speed centrifugal water pump with hydrodynamic bearings used to employ work fluid as lubricant. A three-dimensional numerical study of the turbulent fluid flow was carried out to predict the performance of the pump. The computational model was validated against experimental results during hydraulic tests. Additionally, the effect of the blade number on the head and efficiency of the pump was researched. The blade number of the impeller was changed from 4 to 8 and that of the stay vane was from 3 to 14. The results indicate that the blade number and the matching characteristic of the impeller and the stay vane significantly influenced the performance of the pump. The structure based on the seven-blade impeller and the six-blade stay vane had the highest efficiency (30.8%). Numerical investigations of this study may help reduce the significant cost and time of experimental work for a particular design.