Abstract：To investigate the effect of bend inlet on the dynamic characteristics of mixedflow impellers, adopting numerical simulation method, the performance and characteristics of radial force of mixedflow impellers installed at the point of three pipediameter long away from the bend and on the straight pipe respectively were simulated and analyzed. After steady analysis of the flow field and comparing the axial speed distributions at the impeller inlet, the results show that axial velocity distribution at the inlet has obvious velocity differences in bend plane with bend inlet, but the performances of pumps with straightpipe inlet and bend are basically identical, corresponding with test results. the unsteady simulations under designed flowrate show that the impeller with straight pipe inlet almost has no steady radial force, while the impeller with bend inlet has an obvious increase of steady radial force, especially the unsteady radial force at blade passfrequency, but the unsteady radial force caused by activity and inertia interference remains basically the same. These analyses can be referential for fixedflow and structure design with bend inlet.
［1］成立, Van Esch B P M,刘超，等.喷水推进混流泵叶片径向力［J］. 排灌机械工程学报,2012,30(6):636-640.Cheng Li, Van Esch B P M, Liu Chao， et al. Radial forces of waterjet propulsion mixedflow pump［J］. Journal of Drainage and Irrigation Machinery Engineering, 2012,30(6): 636-640.(in Chinese)［2］仇宝云, 林海江，黄季艳，等.大型立式轴流泵叶片进口流场及其对水泵影响研究［J］.机械工程学报,2005, 41(4)：28-34.Qiu Baoyun, Lin Haijiang, Huang Jiyan, et al. Study on flow field in blade inlet of large vertical axialflow pump and its influence on pump［J］. Chinese Journal of Mechanical Engineering, 2005, 41(4): 28-34.(in Chinese)［3］肖若富,吕腾飞,王福军.双蜗壳式双吸泵隔板结构对叶轮径向力的影响［J］.农业机械学报,2011,42(9):85-88.Xiao Ruofu, Lü Tengfei, Wang Fujun. Influence of rib structure in doublevolute centrifugal pumps on the impeller radial force［J］. Transactions of the Chinese Society for Agricultural Machinery,2011, 42(9): 85-88. (in Chinese)［4］Van Esch B P M, Bulten N W H. Numerical and experimental investigation of hydrodynamic forces due to nonuniform suction flow to a mixedflow pump［C］∥Proceedings of ASME 2005 Fluids Engineering Division Summer Meeting,2005.［5］Van Esch B P M. Performance and radial loading of a mixedflow pump under nonuniform suction flow［J］. Journal of Fluids Engineering, 2009, 131(5): 1-7.［6］Nyirenda P J. Experimental study of hydrodynamic forces in mixedflow pumps［D］. Eindhoven: Technische Universiteit Eindhoven, 2004.［7］朱红耕,袁寿其,刘厚林,等.进水流道对立式混流泵装置能量特性的影响［J］. 江苏大学学报:自然科学版,2007, 28(1):46-51.Zhu Honggeng,Yuan Shouqi,Liu Houlin,et al. Influence of suction box on energy characteristics of vertical mixedflow pumping systems［J］. Journal of Jiangsu University: Natural Science Edition, 2007, 28(1):46-51. (in Chinese)［8］Wang Fujun,Li Yaojun, Cong Guohui, et al. CFD simulation of 3D flow in largebore axialflow pump［J］.Journal of Hydrodynamics, 2006, 18(2): 243-247.［9］施卫东,邹萍萍,张德胜,等. 斜流泵性能预测与叶轮进出口环量分析［J］.农业机械学报,2011,42(9):94-97.Shi Weidong,Zou Pingping, Zhang Desheng,et al. Performance prediction and circulation distribution analysis at impeller inlet and outlet of mixedflow pump［J］. Transactions of the Chinese Society for Agricultural Machinery, 2011, 42(9):94-97. (in Chinese)［10］ 朱荣生,欧鸣雄. 低比转数双吸离心泵回流问题的CFD研究［J］. 农业机械学报,2009,40(4):82-85.Zhu Rongsheng,Ou Mingxiong.Simulation research of reverse flow in low specific speed double suction centrifugal pump［J］.Transactions of the Chinese Society for Agricultural Machinery,2009,40(4):82-85.（in Chinese）［11］Chuang W L. Threedimensional numerical simulation of intake model with cross flow［J］.Journal of Hydrodynamic, 2011,23(3):314-324.［12］施卫东,邹萍萍,张德胜,等. 高比转速斜流泵内部非定常压力脉动特性［J］.农业工程学报,2011,27(4):147-152.Shi Weidong,Zou Pingping,Zhang Desheng,et al. Unsteady flow pressure fluctuation of high specific speed mixedflow pump［J］. Transactions of the CSAE, 2011,27(4):147-152. (in Chinese)［13］赵斌娟.双流道泵内非定常三维湍流数值模拟及PIV测试［D］.镇江:江苏大学能源与动力工程学院，2007.［14］Brennen C E. Hydrodynamics of Pumps［M］. NewYork：Cambridge University Press,2011.
