| Large scale water conservancy projects such as South to North Water Transfer Project need many higher efficiency and steady operating axial flow pumps. Axial flow pump model with excellent performance characteristics can guarantee the energy and cavitation performance and steady operating of prototype axial flow pump. On the basis of hydraulic design practice, performance characteristics of the axial flow pump hydraulic model designed with traditional design methods can not meet the performance demand.The streamline design method is systematically studied and applied to design of axial flow pump models by theorectical analysis, experiments and numerical simulation. These axial flow pump hydraulic models have been adoped in many pump stations.The main work and the achievements are as follows:(1) A method of constant flow rate and altering head is proposed to determine the parameters of the axial flow pump hydraulic model series with different specific speed for convenient pump models selection. The flow rate of axial flow pump model is 0.35 m~3/s , the head is between 2.5～11.0 m, and the specific speed is between 500～1500.(2) The streamline design method for design axial flow pump impeller has been systematically studied. A method of circulation distribution amendment has been put forward by increasing blade section circulation from hub to tip of impeller.The amendment coefficient of the blade sections between hub and tip circulation is increased linearly.A method has been put forward by increasing incidence angle of impeller inlet from hub to tip for further lowering distortion of impeller blades. Incidence angle becomes smaller with higher specific speed, range of which is from 0°to 3°.(3) Suitable numerical simulation methods for three dimentional steady flow of axial flow pump has been studied. A specific speed 1000 axial flow pump model is simulated based on Reynolds-averaged N-S equations, standard k-εturbulence model, SIMPLEC algorithm and unstructured mesh by FLUENT code.The performance characteristics curves of computation is consistent with the one of experiments.In optimum operating condition, the maximum variation of computational head compared with experimental one is 2.52%, and averaged absolute variation is 4.5%. From computational results, velocity and pressure of impeller and guide vane blade surfaces vary regularly. Relative velocity vectors of impeller pressure surfaces are well distributed in nearly cylindrical surface and relative velocity value increasing from hub to tip. Velocity direction of guide vane pressure surfaces is axial. Near impeller hub, static pressure difference varied wildly along blade chord length, while near impeller tip static pressure difference varied gently. Maximum static pressure and average static pressure near impeller tip are higher than near hub. Minimum static pressure of suction surface is near 25% apart from impeller inlet. Impeller exit circulation increases from hub to tip along radial direction, in accord with linear circulation distribution amendment during hydraulic model design.(4) New key parameters selecting laws for axial flow pump design have been proposed, including cascade solidity, hub to tip ratio, blade numbers, foil section thickness of impeller, guide vanes number ,and the axial distance between impeller and guide vane.This study has provided new ideas for the research on the hydraulic model design method of axial flow pump. The developed hydraulic models have good design quality and accuracy, reduce the cost of developmentd and improve prototype pump performance in pump stations. It is of great academic values, and of great significance to water conservancy projects such as South to North Water Transfer Project.
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