A research of axial-flow pump design with method of variable circulation

The formula of distribution coefficient about outlet circulation in the radial direction was derived by the theoretical analysis of the relationship between theoretical head of axial-flow pump with circulation of impeller. The axial-flow model pump with specific speed of 700 was designed with method of variable circulation, employed distribution coefficient according to the derived formula. The hydraulic design method also included streamline method and cascade solidity linearly decreasing from hub to tip of impeller. Based on energy characteristic test, the performance of model pump was determined. The cavitation performance of model pump at the best efficiency point was confirmed through cavitation test. Based on N-S equations and standard k-e model, the designed pump was simulated through full passage. The results show that the actual pump performance parameters agree with the design, the model pump has wide range of high efficiency zone and high cavitation characteristics. The variable circulation method is suitable for the design of high performance axial-flow pump and the derived formula can be a criterion for circulation distribution. The study provides effectively reference to the optimum design of axial-flow pump.