Design And Simulation Of The Inducer For High Speed Centrifugal Pumps

High-speed centrifugal pumps have the advantages of small volume,uniform flow,and high stability of transmission liquids,and are widely used in petrochemical and aerospace fields.When the high-speed centrifugal pump is running,cavitation is prone to appear at the inlet of the impeller and spread into the impeller flow path,which affects the performance and service life of the centrifugal pump.The front inducer is one of the important methods to reduce the influence of cavitation on the centrifugal pump.This paper analyzed the influence of key parameters on the cavitation performance of the inducer and then optimized its structure and performance based on numerical simulation of the flow field.Firstly,the preliminary calculation of hydraulic parameters of the high-speed centrifugal pump was carried out based on the Unitary Flow design theory,and the high-speed pump was modeled and optimized,and then the numerical simulation of the pump was completed by ANSYS-CFX and its cavitation characteristic curves were obtained;Secondly,the detailed geometric parameters of the inducer were determined according to the basic design parameters of the centrifugal pump and the variable pitch inducer was modeled by using Auto CAD and UGNX software;Finally,the important structural parameters such as the number of inducer blades,cascade cascade solidity and entry and exit angles were selected to study their influence on the cavitation performance of the inducer by observing the bubble distribution in flow field under multiple working conditions,and then the inducer was improved structurally base on the simulation results.It was found that the head H of the improved inducer was 1.64 m higher than that of the prototype。When NPSHa=1.36 m,the centrifugal pump can still work normally.Compared with the centrifugal pump without an inducer,the NPSHr of the pump with the improved inducer was increased by 4.69 m,which meets the requirements of the cavitation performance of the inducer.In this paper,the cavitation development law of high-speed centrifugal pump with the front inducer under specific working conditions and the influence of key parameters of the inducer on its cavitation performance were obtained,which may provide references for the design and application of the inducer for high-speed centrifugal pumps.