Features of internal flow in jet nozzle of self-priming centrifugal pump based on large eddy simulation
LI Guidong1, WANG Yang1, YANG Xueming2, ZHAO Lifeng1, WU Wen1, HU Rixin1
1.National Research Center of Pumps, Jiangsu University, Zhenjiang, Jiangsu 212013, China; 2.Anhui Line Electric Pump Co. Ltd., Ningguo, Anhui 242300, China
Abstract：In this paper, large eddy simulation with dynamic sub-grid stress model is adopted to study on fluid dynamics in the jet nozzle of a self-pariming centrifugal pump to examine the effects of transient pressure fluctuation on incipient cavitation characteristics in the pump and the reslts are compared with those obtained by means of the SST k-ω turbulence model. The results show that the time-averaged SST k-ω model cannot adequately simulate the pressure pulsation features at the throat of the nozzle, showing a constant value over time basically. However, the large eddy simulation with dynamic sub-grid stress model is able to get a variable pressure pulsation profil over time, but also the profile agrees well with experimental results, reflecting the actual situation of pressure pulsation. A vrotex ring is formed downstrea the jet in the nozzle, which is generated in the shear layer between the the suctioned fluid with low velocity and the driving fluid of high velocity. The instable vortex induces a voilent pressure fluctuation. A twisted vortex ring propagates downsteam and absorbs the kinetic enegy of the fluid with high velocity. The ring collapses at the thoat to produce the largest prssure pulsation amplide. As a result of this, cavitation is mostly prone to occur there.
李贵东, 王洋, 杨学明, 赵立峰, 吴文, 胡日新. 基于大涡模拟的射流式离心泵射流器内部的流动特性[J]. 排灌机械工程学报, 2017, 35(5): 369-374.
LI Guidong, WANG Yang, YANG Xueming, ZHAO Lifeng, WU Wen, HU Rixin. Features of internal flow in jet nozzle of self-priming centrifugal pump based on large eddy simulation. Journal of Drainage and Irrigation Machinery Engin, 2017, 35(5): 369-374.
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