|
|
|
| Numerical simulation of end surface erosion characteristics of hydro-turbine guide vane |
| HAN Wei1,2, CHEN Yu1, LIU Yi1,2*, LI Guangxian1, WANG Jie1, WANG Tengda1 |
| 1.College of Energy and Power Engineering, Lanzhou University of Technology, Lanzhou, Gansu 730050, China; 2.Key Laboratory of Fluid Machinery and Systems, Gansu Province, Lanzhou, Gansu 730050, China |
|
|
|
|
Abstract To study the solid-liquid two-phase flow features in the clearances between guide vane end surfaces and casing, as well as the erosion condition of two end surfaces, the unstead three-dimensio-nal flow in a cylinder and a backward-facing step flow channel, which is a simplified model of the end clearance flow in a real hydro-turbine guide vane, was numerically simulated based on the RNG k-ε turbulence model and discrete phase model(DPM)in Fluent. In simulations, the solid particle vo-lume fractions were 1%, 5%, 7% and 10%, the particle diameters were 0.020, 0.050, 0.075 and 0.100 mm, and different inlet velocities were used. Through steady numerical simulations, the distribution of average erosion rate on the upper and lower end surfaces was obtained, and the erosion pattern and locations were analyzed. The results indicate that the distribution of average erosion rate in flow field is closely related to the physics models and the parameter settings for the two-phase flow. With increasing inlet liquid velocity and particle volume fraction, the average erosion rate augments. The erosion positions mainly are located in the front of the cylinder, the reattachment point downstream the step and the outlet of the step. The maximum average erosion rate is about 2.0×10-6 kg/(m2·s). With increasing particle diameter, the average erosion rate decreases due to an increasing inertial force. When the particle diameter is less than 0.020 mm, heavier erosion occurs in comparison with the rate at large diameters, particularly, the maximum average erosion rate is about 2 times the rate at 0.100 mm particle diameter.
|
|
Received: 18 August 2017
|
|
|
|
| [1]杨从新, 董富弟, 程效锐, 等. 含沙水流中粒径对离心泵叶轮磨损特性影响的数值分析[J]. 兰州理工大学学报, 2014,40(4):45-50. YANG Congxin, DONG Fudi, CHENG Xiaorui, et al. Numerical analysis of effect of sand particle size of silt-laden water flow on wear characteristics of centrifugal pump impeller[J]. Journal of Lanzhou University of Technology, 2014,40(4):45-50.(in Chinese)[2]THAPA B S, THAPA B, ELEVIK M, et al. Optimizing runner blade profile of Francis turbine to minimize sediment erosion[C]//Proceedings of 26th IAHR Sympo-sium on Hydraulic Machinery and Systems. [S.l.]: IOP Publishing Ltd. 2012.[3]黄剑峰, 张立翔, 姚激, 等. 水轮机泥沙磨损两相湍流场数值模拟[J]. 排灌机械工程学报, 2016,34(2):145-150. HUANG Jianfeng, ZHANG Lixiang, YAO Ji, et al. Numerical simulation of two-phase turbulent flow in Francis turbine passage on sediment erosion[J]. Journal of drainage and irrigation machinery engineering, 2016,34(2):145-150.(in Chinese)[4]KOIRALA R, ZHU Baoshan, NEOPANE H P. Effect of guide vane clearance gap on Francis turbine performance[J]. Energies, 2016,9(4):275.[5]张广, 魏显著, 宋德强. 导叶端面间隙泥沙磨损数值预测研究[J]. 大电机技术, 2017(3):64-68. ZHANG Guang, WEI Xianzhu, SONG Deqiang. Numerical study on solid-liquid two-phase flow in francis turbine runner[J]. Large electric machine and hydraulic turbine, 2017(3):64-68.(in Chinese)[6]THAPA B S, DAHLHAUG O G, THAPA B. Velocity and pressure measurements in guide vane clearance gap of a low specific speed Francis turbine[C]//Procee-dings of IOP Conference Series: Earth and Environmental Science, 2016,49(6):1-10.[7]THAPA B S, DAHLHAUG O G, THAPA B. Sediment erosion in hydro turbines and its effect on the flow around guide vanes of Francis turbine[J]. Renewable and sustainable energy reviews, 2015,49:1100-1113.[8]王威. 圆柱绕流数值模拟[J]. 辽宁化工, 2016(7):877-878. WANG Wei. Numerical simulation of flow around a circular cylinder[J]. Liaoning chemical industry, 2016(7):877-878.(in Chinese)[9]魏治强, 郝晓青, 杜俊杰. 浅析基于Mixture模型的固液两相流[C]//第十三届沈阳科学学术年会论文集(理工农医). 沈阳: 沈阳农业大学出版社, 2016:743-747.[10]邱骁, 丁珏, 王忠杰, 等. 湍流分离流中沙粒的扩散机制[J]. 上海大学学报(自然科学版), 2016,22(5):586-596. QIU Xiao, DING Jue, WANG Zhongjie, et al. Particles diffusion mechanism in turbulent separation flow[J]. Journal of Shanghai University(natural science edition), 2016,22(5):586-596.(in Chinese)[11]ZHANG Yuliang, LI Yi, ZHU Zuchao, et al. Computational analysis of centrifugal pump delivering solid-li-quid two-phase flow during startup period[J]. Chinese journal of mechanical engineering, 2014,27(1):178-185.[12]HUANG Si, ZOU Wenlang, ZHOU Jinju, et al. Unsteady numerical simulation on solid-liquid flows and wear in a centrifugal pump based on DPM model[J]. Machine tool & hydraulics, 2016,44(6):1-5.[13]ANSYS Inc. Ansys Fluent 12.0: theory guide[M]. [S.l.]: ANSYS Inc, 2009.[14]李亮, 申龙涉, 范开峰, 等. 弯管中多相流冲刷腐蚀数值模拟[J]. 辽宁石油化工大学学报, 2014,34(3):48-52. LI Liang,SHEN Longshe,FAN Kaifeng, et al. Numerical simulation of bend multiphase flow erosion[J]. Journal of Liaoning Shihua University, 2014,34(3):48-52.(in Chinese) |
|
|
|
