Analysis of flow in liquid jet pump—Part Ⅰ:Experiment and threedimension numerical simulation
WANG Song-Lin, WANG Yu-Chuan, GUI Shao-Bo, GAO Chuan-Chang, CAO Shu-Liang
(1.School of Water Conservancy, North China University of Water Resources and Electric Power, Zhengzhou, Henan 450011, China; 2.State Key Laboratory of Hydroscience and Engineering, Tsinghua University, Beijing 100084, China; 3.Changjiang Institute of Survey, Planning, Design and Research, Wuhan, Hubei 430010, China; 4. Institute of Electric Power, North China University of Water Rosources and Electric Power Zhengzhou, Henan 450011, China)
Abstract：The performance of a horizontally installed liquid jet pump with side suction was tested and its internal flow was analyzed by numerical simulation. The standard k-ε twoequation turbulence model and SIMPLE method were adopted in the numerical simulations. The simulated performance parameters agreed well with experimental ones at the best efficiency point. Twofluid mixing process and its flow pattern in the pump were analyzed as well based on the numerical simulation results. At a large flow ratio (q>0.8), a reduced local pressure ratio and the suctioned liquid with loss of energy are observed in the region from throat inlet to 0.6 times the throat diameter down stream due to mixing and local frictional losses. As the flow ratio increases, the energy obtained by the suction fluid is decreased, thus the distance where an energy transfer takes place between two fluids increases; the two fluids velocity becomes uniform once the suctioned liquid travels in the nozzle for a distance as long as 6-8 times the throat diameter. However, the peak pressure occurs in less than that distance. Such a two liquid mixing process in the throat is similar to that of fully developed turbulent flow. For the side suction jet pump, there are vortexes in the crosssection induced by a secondary flow due to asymmetric flow in the suction chamber, but the velocity of the secondary flow is so smaller than the mainstream velocity in the throat that the major characteristics of the jet pump can be obtained by a two dimensional theoretical analysis.
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