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| Numerical analysis on velocity field of water-jet pump under non-uniform inflow |
| JIN Shibin1, CAO Puyu2, WANG Yang2 |
| 1.Wenling Bureau of Quality Supervision and Inspection, Wenling, Zhejiang 317500, China; 2.National Research Center of Pumps, Jiangsu University, Zhenjiang, Jiangsu 212013, China |
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Abstract To research the correlation between non-uniform inflow and the hydrodynamics of water-jet pump, the outflow velocity field in the intake duct was analyzed by the CFX-Post software. The velocity field of non-uniform outflow was selected as the inflow boundary condition in the process of simulation, and the hydrodynamics of water-jet pump was achieved. Then the comparison of hydrodynamics between non-uniform and uniform inflow conditions was carried out. The results show that the hydrodynamics of water-jet pump in the non-uniform inflow condition is lower than that in the uniform inflow condition. With the non-uniformity of the inflow field increasing, the decreasing amplitude of the head and efficiency is increasing. According to velocity components of non-uniform, the reason that the pump hydrodynamics reduced in the non-uniform inflow condition was analyzed. Results show that the traditional design method can not meet the working requirements, and the correlation assumptions are unavailable to the condition of non-uniform inflow. The existence of inlet pre-swirling in the non-uniform inflow field is against the "no pre-swirling" hypothesis, so the angle of attack and the lift coefficient of airfoils decrease. The interaction between axial and radial velocity in the non-uniform inflow field results in the nonlinear distribution of the meridional velocity and circulation. The circumference independence assumption is invalid owing to the change of radial velocity. The non-uniform inflow also impacts the field of blades, which is concentrated at the shroud. The secondary circumfluence blocks the flow passages, and weakens the flow capacity of the water-jet pump. Meanwhile, it contributes to the deviation curve of blade loading at the shroud, and impairs the working ability of the water-jet pump. In conclusion, the non-uniform inflow is the major reason for the decrement of propulsion efficiency,therefore the non-uniform inflow condition should be considered during the process of water-jet pump designing.
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Received: 10 August 2015
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| [1]BULTEN N. A breakthrough in waterjet propulsion systems[C]//Proceedings of International Maritime Defence Exhibition and Conference. Doha, Qatar: DIM-DEX, 2008.[2]ZANGENEH M, DANESHKHAH K, DACOSTA B. A multi-objective automatic optimization strategy for design of water-jet pumps[C]//Proceedings of International Conference of Water-jet Propulsion—V. London: RINA, 2008.[3]ALLISON J L. Model tools for water-jet pump design and research advances in the field[C]//Proceedings of International Conference on Water-jet Propulsion—II. London: RINA, 2004.[4]李均.基于三元理论喷水推进轴流泵改进设计[J].机电设备,2015(6):72-78. LI Jun. Optimization of axial water jet flow pump based on 3D design method[J].Mechanical and electrical equipment,2015(6):72-78.(in Chinese)[5]DUCCIO B, MEHRDAD Z, REIMA A J E. Parametric design of a waterjet pump by means of inverse design CFD calculations and experimental analyses[J]. Journal of fluid engineering, 2010, 132(3): 031104.[6]TAYLOR T E, KERWIN J E, SCHERER J O. Water-jet pump design and analysis using a coupled lifting-surface and RANS procedure[C]//Proceedings of International Conference on Water-jet Propulsion——II. Amsterdam, Netherland, 1998.[7]王福军, 张玲, 张志民. 轴流泵不稳定流场的压力脉动特性研究[J]. 水利学报, 2007, 38(8):1003-1009. WANG Fujun, ZHANG Ling,ZHANG Zhimin.Analysis on pressure fluctuation of unsteady flow in axial-flow pump[J]. Journal of hydraulic engineering, 2007, 38(8):1003-1009.(in Chinese)[8]BULTEN N W H. Numerical analysis of waterjet propulsion system[D]. Eindhoven: Technical University of Eindhoven, 2006.[9]王永生,魏应三. 喷水推进器进水流道不均匀度统一描述[J]. 武汉理工大学学报, 2009, 31(8): 159-163. WANG Yongsheng, WEI Yingsan. Unified description of outflow non-uniformity of waterjet duct[J]. Journal of Wuhan University of Technology, 2009, 31(8): 159-163.(in Chinese)[10]刘瑞华,曹璞钰,王洋,等. 无轴式喷水推进泵的水动力特性[J]. 排灌机械工程学报,2015,33(5): 380-386. LIU Ruihua,CAO Puyu,WANG Yang,et al.Hydrodynamic characteristics of shaft-less waterjet pump[J]. Journal of drainage and irrigation machinery engineering,2015,33(5):380-386.(in Chinese)[11]金平仲, 曾松祥, 王立祥,等. 船舶喷水推进及轴流式推进泵论文集[C]. 上海:中国船舶工业集团公司第708研究所, 1991.[12]关醒凡. 现代泵技术手册[M]. 北京: 中国宇航出版社, 1995.[13]朗继先. 轴流泵变轴面速度流型设计理论的研究[J]. 北京农业工程大学学报, 1987, 7(4): 47-55. LANG Jixian. The variable meridional velocity flowpattern design theory for axial-flow pump[J].Journal of Beijing Agricultural Engineering University, 1987, 7(4): 47-55.(in Chinese)[14]BONAIUTI D, ZANGENEH M, AARTOJARVI R, et al. Parametric design of a waterjet pump by means of inverse design, CFD calculation and experimental analyses[J].Journal of turbomachinery, 2010, 132(3): 1-15.[15]江伟, 李国君, 张新盛. 基于叶片载荷分布的离心泵叶轮水力性能优化[J]. 哈尔滨工程大学学报,2015,36(4):505-510. JIANG Wei,LI Guojun,ZHANG Xinsheng. Optimization of the hydraulic performance of a centrifugal pump impeller based on the blade load distribution[J]. Journal of Harbin Engineering University,2015,36(4):505-510.(in Chinese) |
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