Abstract:The RNG k-ε turbulence model was used to simulate the turbulent flow in the centrifugalimpeller with or without shroud. It is found from the calculation results of the shrouded impeller that there is alarge area of recirculation flow near blade suction surface at low flow rate, and there is an obvious vortex justupstream of the impeller leading edge near shroud at high flow rate. The existences of clearance in theunshrouded impeller arouse two vortices. Compared with shrouded impeller, the head, capacity and efficiencyof the unshrouded impeller decrease. The best efficiency is lowered by 18%. A transparent acrylic centrifugalpump which is suitable for PIV measurement has been developed. The results of PIV measurement can be usedto validate the numerical solution and show that the flow in one passage is different to another even at bestefficiency point.
[1] Cao S L,Goulas A,Yakinthis K.Numerical simu lation of three-dimensional flow in a centrifugal pump impeller[A].北京,1998:11-418[2] 李巍,王国强,刘立军.离心叶轮内三维紊流流动数值模拟[J].上海交通大学学报,2000,34(1):43-147[3] Yakhot V,orazag S A.Renormalization-group analysis of tur bulence[J].Physical Review Letters,1986,57(14):1722-1724[4] Moore J,Moore J G.Calculation of three-dimensional viscous flow and wake development in a centrifugal impeller[J].Journal of Engineering for Power-Transactions of the ASME,1981,103(3):367-372[5] 刘立军,徐忠,史峰.离心叶轮内部三维湍流流场的数值分析[J].工程热物理学报,1996,17(3):296-300[6] 杨华,刘超,汤方平.采用PIV研究离心泵转轮内部瞬态流场[J].水动力学研究与进展A辑,2002,17(5):547-552