Numerical Simulation And Experiment Research Of Anti-cavitation Performance Of The High-speed Centrifugal Pump With An Inducer

As the centrifugal pump runs at a high speed, the centrifugal impeller is easy to cavitate.The occurrence of cavitation will destroy the centrifugal pump’s performance, cause cavitationdamage, aggragate the unit vibration, and sometimes even can cause disastrous consequences. Atpresent, one of the most effective ways to prevent the high-speed centrifugal pump cavitation isto equip an inducer before the centrifugal impeller. Thus to research the cavitation of thecentrifugal pump and inducer is important and necessary. At present, the research of rotatingcavitation flow is still in the period of exploration. Especially the cavitation flow mechanism ofhydraulic machinery and the inducer is not completely clear. In the field of the academic andengineering, to reveal the mechanism of cavitation flow is a problem needs to resolve urgently.This paper is supported by the National Natural Science Fund Project (NO.51076144), NaturalScience Foundation of Zhejiang Province (NO. Y1100013) and Public Industrial Projects ofZhejiang Province (NO.2012C21013). Based on the theoretical analysis, numerical calculation,external characteristics experiments and visualization experiments, the high-speed centrifugalpump and inducer cavitation evolution, cavitation flow mechanism are analyzed systematicallyin this paper.Firstly, Single-phase flow numerical calculation under non-cavitation state is carried out,and the mechanism of flow in the centrifugal pump and inducer is revealed on the design workcondition and on the different work conditions. Secondly, rotation cavitation flow numericalcalculation under cavitation state on different work conditions is done. The mechanism ofrotation cavitation flow is revealed. Thirdly, the performance experiments of high-speedcentrifugal pump with different inducers is carried out on different working conditions, and theperformance curves are got. Finally, the cavtitation visual experiment are carried out, and theevolution rules of cavitation are revealed further. In this paper, numerical calculation, externalperformance and visualization experiment are combined, tested and verified, which proved thefeasiblility of the research method and the correct of the conclusion.The main research work is as follows.（1）Single-phase flow numerical calculation under non-cavitation state on different workconditions is carried out. Taking the results of the external performance experiment as boundaryconditions, single-phase flow of the high-speed centrifugal pump with different inducers are simulated numerically, on design work condition and different work conditions. The pressuredistribution in the centrifugal pump and the inducers are got. The lowest pressure in the pumpand inducers are got. The flow mechanism in the impeller and the inducer under non-cavitationcondition is revealed.（2）Rotation cavitation flow numerical calculation under cavitation state on different workconditions is done. Rotation cavitation flow under cavitation state on different work conditions inthe centrifugal pump with different inducers is done. The rotating cavitation phenomenon isrevealed, with different inducers and under different work condtions. The cavitation developmentprocess in the inducer and impeller under different cavitation coefficient is revealed.（3）The performance experiments of high-speed centrifugal pump with different inducersare carried out. The experiments are under different working conditions. Through the experiment,the external performance curve of pump is got, which the rotational speed is from2000r/min to8000r/min. The inducer with good anti-cavitation performance is variable-pitch inducer. Thevariable-pitch inducer with three blades has better anti-cavitation performance. The experimentsof the pump on the similar conditions under different rotation speed are carried out, and theresults show that the anti-cavitation performance is reduced with the increase of the rotation.（4）The cavtitation visual experiments are carried out. The evolution rules of cavitation,the location of cavitation and the degree of the cavitation are revealed further. Visualization wascarried out to study the splitter inducer of rotating cavitation by analyzing the high speed videocamera pictures.