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| Numerical simulation of unsteady flow in multiphase rotodynamic pumps |
| YU Zhi-Yi, ZHANG Qin-Zhao, HUANG Ruo, CAO Shu-Liang |
(1. School of Mechanical Engineering, Beijing Institute of Technology, Beijing 100081, China; 2. Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084, China; 3. State Key Laboratory of Hydroscience and Engineering, Tsinghua University, Beijing 100084, China) |
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Abstract To further investigate the mechanism of phase separation and gas accumulation in multiphase rotodynamic pumps, on the assumption of tiny bubbly flow, based on a twofluid model, the gasliquid twophase unsteady flow in a multiphase rotodynamic pump, with an IGVF（inlet gas volume fraction）of 15%, was numerically simulated. In the simulation, the k-ε based SST (Shear Stress Transport) model was used for turbulence; the drag force and the added mass force were taken into consideration in the interfacial momentum transfer terms; the steady solution of single water phase flow was specified as the initial flow field. Under this IGVF, five flow rate conditions were simulated, and taking the most optimal working condition as an example, the twophase flow field and its temporal evolution were analyzed; the evolution characteristic and the calculation method of pump head were explored. The results show that, due to different centrifugal forces on the two phases, the gas is distributed mainly around the hub; affected by the change of the flow passage and the rotation of the impeller, the air mass starts to form at the inlet of the impeller. In addition, the gas volume fraction field and pressure field fluctuate in transportation, which results in severe oscillation of the pump head and instability of the pump system. The comparison of the head characteristics between the simulation and the experiment validates the reliability of the numerical model and method.
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Received: 10 June 2012
Published: 30 April 2013
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| ［1］Mack S, Stuart S. Multiphase pumping as an alternative to conventional separation, pumping and compression. ［C］／／34th Annual PSIG Meeting. Portland, USA：［s.n.］， 2002.［2］Caridad J, Asuaje M, Kenyery F, et al. Characterization of a centrifugal pump impeller under twophase flow conditions ［J］. Journal of Petroleum Science and Engineering, 2008, 63(1/2/3/4): 18-22.［3］Cao Shuliang, Peng Guoyi, Yu Zhiyi. Hydrodynamic design of rotodynamic pump impeller for multiphase pumping by combined approach of inverse design and CFD analysis ［J］. Journal of Fluids Engineering, 2005, 127(2): 330-338.［4］朱宏武, 刘文霄. 螺旋轴流式多相泵油气混输试验研究［J］. 石油矿场机械,2008, 37(10): 79-82.Zhu Hongwu, Liu Wenxiao. Tests study of the helicoaxial multiphase pump ［J］. Oil Field Equipment, 2008, 37(10): 79-82. (in Chinese)［5］Tremante A, Moreno N, Rey R, et al. Numerical turbulent simulation of the twophase flow (liquid／gas) through a cascade of an axial pump ［J］. Journal of Fluids Engineering, 2002, 124(2): 371-376.［6］卢金铃,席光,祈大同. 离心泵叶轮内气液两相三维流动数值研究［J］. 工程热物理学报, 2003, 24(2): 237-240.Lu Jinling, Xi Guang, Qi Datong. Numerical study on the gasliquid twophase 3D flow in the impeller of a centrifugal pump ［J］. Journal of Engineering Thermophysics, 2003, 24(2): 237-240. (in Chinese)［7］Yu Zhiyi, Wang Guoyu, Cao Shuliang. Extended twofluid model applied to analysis of bubbly flow in multiphase rotodynamic pump impeller ［J］. Frontiers of Mechanical Engineering in China, 2009, 4(1): 53-59.［8］Lei C, Ahmed F G. Simulation of oxycoal combustion in a 100 kW(th) test facility using RANS and LES: A validation study ［J］. Energy ＆ Fuels, 2012,26(8): 4783-4798.［9］Sooran N, Seyed H, Hashemabadi. CFD simulation of inlet design effect on deoiling hydrocyclones separation efficiency ［J］. Chem Eng Technol, 2009, 32(12): 1885-1893.［10］Abdullah A K. The virtual mass of a rotating sphere in fluids ［J］. J Applied Mechanics, 2005, 72 (5): 801-802.［11］曹树良,余志毅,王国玉,等. 叶片式气液混输泵的实验研究［J］. 流体机械, 2002,10(专刊): 346-349.Cao Shuliang, Yu Zhiyi, Wang Guoyu, et al. Experimental study on a multiphase rotodynamic pump ［J］. Fluid Machinery, 2002, 10(Special ed): 346-349. (in Chinese) |
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