Research On The Optimized Design Of Centrifugal Pump Impeller Based On Agent Model

Centrifugal pumps have a vital role in the development of national economy and livelihood of people.Improving the performance of centrifugal pumps has been a hot topic for researchers.This is especially true for methane pumps,whose efficiency is crucial to reduce rocket operating costs.In this paper,we study the optimized design of methane pump（centrifugal pump）impeller based on the agent model technology to improve the performance of methane pump.The details of the study and the main research results are as follows.1.Response surface proxy model,Kriging proxy model,and particle swarm algorithm optimized least squares support vector machine proxy model（PSO-LSSVR）were developed to investigate the most suitable proxy models for centrifugal pump performance prediction.The performance of these three proxy models is compared in terms of maximum absolute relative error,root mean square error,and relative root mean square error,respectively,and the results show that the PSO-LSSVR proxy model has better prediction results than the other two proxy models.Therefore,the PSO-LSSVR proxy model technique was selected for the optimal design study of the turbine pump.2.The particle swarm algorithm in the intelligent swarm algorithm is used to find the optimal solution for the optimized design of the centrifugal pump impeller in the established PSO-LSSVR agent model space.After several iterations and CFD verification,as well as the output results show that the optimized impeller meets the design requirements with an efficiency increase of 1.8%under the condition that the head is basically unchanged.3.Based on the above work,the internal flow field analysis of the impeller of the centrifugal pump before and after optimization and the energy loss analysis of the impeller of the centrifugal pump before and after optimization were carried out using the entropy production method.The internal flow field analysis shows that the optimized pump has more uniform internal pressure distribution,smoother internal flow,less turbulent kinetic energy and lower intensity of vortex nuclei distribution area compared with the initial pump.The results of entropy production analysis showed that the turbulent dissipation entropy production△S_P,TD and wall entropy production△S_P,W of the optimized pump were significantly reduced.The optimized impeller structure improves the flow conditions along the leading and trailing edges inside the impeller,increasing the operating efficiency of the pump and reducing the entropy yield（i.e.,energy loss）.