水轮机活动导叶端面间隙磨蚀特性数值模拟  

Numerical simulation of end surface erosion characteristics of hydro-turbine guide vane

作　　者：韩伟[1,2] 陈雨 刘宜 李光贤[1] 王洁 王腾达 HAN Wei;CHEN Yu;LIU Yi;LI Guangxian;WANG Jie;WANG Tengda(College of Energy and Power Engineering,Lanzhou University of Technology,Lanzhou,Gansu 730050,China;Key Laboratory of Fluid Machinery and Systems,Gansu Province,Lanzhou,Gansu 730050,China)

机构地区：[1]兰州理工大学能源与动力工程学院,甘肃兰州730050 [2]甘肃省流体机械及系统重点实验室,甘肃兰州730050

出　　处：《排灌机械工程学报》2018年第5期404-412,共9页Journal of Drainage and Irrigation Machinery Engineering

基　　金：国家自然科学基金资助项目(51669012);西华大学重点实验室开放基金资助项目(szjj2017-092)

摘　　要：为了研究水轮机活动导叶端面间隙固液两相流动的规律,以及间隙上下表面的磨损情况,基于Fluent软件的RNG k-ε湍流模型和DPM模型,结合水轮机活动导叶端面间隙流的简化模型(圆柱绕流和后台阶流),数值模拟了不同进口速度下,沙粒体积分数分别为1%,5%,7%,10%以及沙粒粒径分别为0.020,0.050,0.075,0.100 mm时,活动导叶端面间隙的三维非稳态流动.通过定常数值模拟得到不同工况下间隙上下表面的平均磨损率分布,分析磨蚀规律和磨蚀位置.结果表明:流场中平均磨损率分布受间隙流模型的结构和两相流参数设置影响较大.随着进口速度和沙粒体积分数增大,间隙流模型上下表面平均磨损率增大,磨损主要集中在轴前、台阶下游再附点位置以及间隙流出口处,最大平均磨损率约为2.0×10^(-6)kg/(m^2·s).随着沙粒粒径增大,由于惯性力作用,模型上下表面平均磨损率减小;在沙粒粒径小于0.020 mm时,磨损情况相比其他粒径更严重,最大平均磨损率约为0.100 mm时的2倍.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-εturbulence 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/(m 2·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.

关 键 词：水轮机导叶 间隙流 平均磨损率 离散相模型 数值模拟 

分 类 号：TK730[交通运输工程—轮机工程]