The Influence Of The Inducer On The Low Specific Speed Centrifugal Pump's Cavitation Characteristics And The Internal Flow Field

The low specific speed centrifugal pump has the characteristics of small flow and high head;it has been widely used in the oil,chemical industry and other fields.The poor cavitation performance in the pump has always been a key problem in research and development of the low specific speed centrifugal pump.When the cavitation occurs in the centrifugal pump,it will produce a series of problems such as vibration and noise.When the cavitation become very serious,the pump cannot work,this will seriously influence the efficiency of the pump and the stability of the operation.Equipping an inducer in front of the centrifugal impeller is the main solution to improve the cavitation performance of the centrifugal pump.Thus it is very important and necessary to study the cavitation in the low specific speed centrifugal pump.In this paper,numerical simulation and experiment have been adopted to analyze the cavitation characteristics and internal flow of the low speed centrifugal pump with or without an inducer.The main research work is as follows:(1)The centrifugal pump's main fluid domain is established by the three-dimensional modeling software UG8.0,and the main fluid domain concludes two-blade inducer,impeller and volute.Then the centrifugal pump is imported in the ICEM for meshing and then simulated by the CFD software Pump Linx.(2)Under non-cavitation condition,based on the standard k-? turbulence mode,the flow field of the low specific speed centrifugal pump has been calculated at different working condition.The impeller's static pressure,absolute velocity and the pressure pulsation on the volute are analyzed.(3)Under cavitation condition,based on the full gas model,the flow field of the low specific speed centrifugal pump has been calculated at rated condition.Their cavity phase distribution in the impeller are analyzed,the centrifugal pump with and without an inducer‘s pressure pulsations in the inducer wall,impeller passage and the volute are discussed.The cavity phase distributions at the inducer are also analyzed.(4)The external performance and cavitation performance experiment on the centrifugal pump with an inducer are carried out on the test bed in this paper.Through the experiments,the performance curves and cavitation performance curves are obtained;the numerical simulation results and experiment results are compared and analyzed.The reliability of the numerical simulation is verified.