Water Resources and Power

In order to reduce hydraulic losses between the outlet of the impeller and the inlet of the guide vane, an axial flow pump with a speed ratio of 1 296 was selected as the research object. By combining response surface analysis and numerical simulation, the influence of different structural parameters of the impeller and guide vane on the hydraulic efficiency was studied. The correction coefficient of the impeller outlet angle ξ, inlet incidence angle of guide vane Δβ, and the axial spacing S were selected as the optimization design variables, while the pump efficiency was taken as the response value. A multivariate quadratic regression equation was established to describe the relationship between the optimization variables and hydraulic efficiency. The research results show that the inlet incidence angle of guide vane Δβ had the greatest impact on the performance of the axial flow pump, followed by the axial spacing S, while the influence of the correction coefficient of the impeller outlet angle ξ was the smallest. Furthermore, both the guide vane inlet incidence angle Δβ and the impeller outlet angle correction coefficient ξ had a significant interaction with the axial spacing S. Based on the range of values for the optimization variables, the optimal parameter combination was determined as ξ =1.2, Δβ =-0.7°, and S = 8.5 mm. After optimization, the axial flow pump showed a 0.61 m increase in lift and a 2.6% increase in efficiency under the design operating conditions. The research results provide a reference for further improving the hydraulic performance of axial flow pumps.