Numerical Simulation and Experiment on Free-surface Air-entraining Vortices in Pump Sump

被引：0
|
作者：
Wu P. [1 ]
Guo Z. [1 ]
Qian Z. [1 ]
Wang Z. [1 ]
Chen F. [1 ]
机构：
[1] State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan
来源：
Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery | 2018年 / 49卷 / 02期
关键词：
Air entrainment; Free-surface vortex; Numerical simulation; Pump sump;
D O I：
10.6041/j.issn.1000-1298.2018.02.016
中图分类号：
学科分类号：
摘要：
In order to suppress the free-surface air-entraining vortex in pump sumps, the three-dimensional unsteady vortex flow in a pump sump was calculated by computational fluid dynamics (CFD) method. The dynamic process of the free-surface air-entraining vortex was simulated. And an experimental model was conducted to verify the CFD method. In this experimental model, a circular plate device was placed between the free surface and the inlet of the bell-mouth to suppress the air entrainment. Furthermore, a parameter called helicity density was adopted to reveal the mechanism of air-entrainment and its suppression. The results showed that the numerical method used in this study can predict the dynamic process of air-entrainment for the free-surface vortex accurately. The helicity density played a very important role in the formation of air entrainment. When the dimple appeared on the free surface, a helicity density tube was formed around the inlet of the bell-mouth. As air entered into water, the other helicity density tube was formed under the free surface. When the two helicity density tubes were connected with each other, the air-core from the free-surface to the inlet of the bell-mouth was formed. This meant that the mechanism of air-entrainment for the free-surface vortex was the connection of the helicity density tubes which provided a passage for air to pass through. Moreover, the circular plate with enough dimension can successfully suppress the air-entrainment through cutting off the helicity density tubes. © 2018, Chinese Society of Agricultural Machinery. All right reserved.
引用
收藏
页码：120 / 125
页数：5
相关论文
共 21 条
  • [1] He Y., Main advances of research on vortices in pump sumps, Journal of Hydroelectric Engineering, 23, 5, pp. 92-96, (2004)
  • [2] Cong G., Wang F., Applicability of turbulence models in numerical simulation of vortex flow in pump sump, Transactions of the CSAE, 24, 6, pp. 31-35, (2008)
  • [3] Qian Z., Wu P., Guo Z., Et al., Numerical simulation of air entrainment and suppression in pump sump, Science China Technological Sciences, 59, 12, pp. 1847-1855, (2016)
  • [4] Okamura T., Kamemoto K., Matsui J., CFD prediction and model experiment on suction vortices in pump sump, Proceedings of the 9th Asian International Conference on Fluid Machinery, (2007)
  • [5] Patel V.C., Rajendran V.P., Measurement of vortices in model pump-intake bay by PIV, Journal of Hydraulic Engineering, 126, 5, pp. 322-334, (2000)
  • [6] Liu C., Liang H., Jin Y., Et al., PIV measurements of intake flow field in axial-flow pump, Transactions of the Chinese Society for Agricultural Machinery, 46, 8, pp. 33-41, (2015)
  • [7] Tang H., Xu X., Zhang Z., Particle image velocimetry technique and its application of free vortex at vertical intake, Journal of Hydrodynamics Ser, A, 14, 1, pp. 128-134, (1999)
  • [8] Zhu H., Xi B., New method for pump sump hydraulic model study, Transactions of the Chinese Society for Agricultural Machinery, 34, 5, pp. 72-75, (2003)
  • [9] Tang F., Geng W., Yang G., Influence of the flow pattern in the sump on the flow field of pump inlet, Drainage and Irrigation Machinery, 22, 5, pp. 12-14, (2004)
  • [10] Li Y., Li X., Wu Y., Et al., PIV experiments on flow in a closed model pump suction sump, Transactions of the CSAE, 17, 3, pp. 45-48, (2001)
123