Analysis Of The Effect Of Splitter Blade On The Performance Of Plastic Centrifugal Pump

Plastic centrifugal pumps are widely used in economical production,where impellers are generally made of polymer materials such as polyvinylidene fluoride and reinforced polypropylene.However,the unfavorable strength of those materials often leads to impeller deformation and even structural damage in severe cases.Centrifugal pumps with a specific speed(ns)from 30 to 80 are referred to as low specific speed ones.The most prominent problems with a low specific speed centrifugal pump are its low efficiency and unstable internal flow,leading to unstable operation.Therefore,there is a need for an in-depth study of that phenomenon and the structures concerning the internal operation of centrifugal pumps.The internal flow field of a low specific speed centrifugal pump can be improved by designing its splitter blade.Some structural parameters such as the inlet diameter of a splitter blade are associated with the pump performance.In the relevant literature,there are few studies on the combination of the structural parameters of a splitter blade combined with pump performance.In order to investigate the influence of splitter blades on pump performance,the influence of the structural parameters of a splitter blade on the pump performance is studied based on fluid-structure interaction and structural parameter optimisation.The major efforts of this thesis are as follows.1.Based on the speed coefficient method,the components of the plastic centrifugal pump were designed,and the relevant software was used to model the components in two dimensions and three dimensions respectively.2.With the help of ANSYS CFX software,flow field simulations were carried out on an impeller model with a splitter blade,and the results were analysed to investigate the influence of the structural parameters of the splitter blade on the pump performance.The influence of the relevant structural parameters of the splitter blade on the structural characteristics of the impeller was investigated by the fluid-structure interaction method.3.The coupling analysis of the plastic centrifugal pump under muti-physical field conditions was carried out,showing its displacement deformation and stress distribution range under the relevant coupling conditions and providing a reference for the structural design of impellers.4.The orthogonal experiment on the performance of plastic centrifugal pump was designed and completed.The efficiency and head of plastic centrifugal pump were taken as evaluation indexes,and the structural parameters of splitter blades were taken as horizontal factors to complete the orthogonal experiment on the performance of plastic centrifugal pump.The range analysis was carried out on the experimental data,and the order of the influence of each structural parameter on the efficiency and head and the optimal structural combination parameters are obtained.5.Based on the orthogonal tests,the mathematical model of the structural parameters and the evaluation indices was established using the least squares method.Based on the model,the fish swarm algorithm was applied to optimise the structural parameters affecting the head,obtaining the optimal relevant structural parameter combination.6.Through pump performance tests,the optimal relevant splitter blade structural parameter combination was verified.The data was collated,showing how the splitter blade structural parameters influence the pump performance.