过渡阶梯不同台阶组合对坝面掺气特性的影响研究  

Impact Study of Transitional Ladder Steps Combination on the Integration of Dam Surface Aeration Characteristics

作　　者：王强 杨具瑞[2] 龙远莎 朱向梅 WANG Qiang;YANG Ju-rui;LONG Yuan-sha;ZHU Xiang-mei(College of agricultural and forestry engineering and planning,Tongren University,Tongren 554300,China;College of modern agricultural engineering,Kunming University of Science and Technology,Kunming 650500,China)

机构地区：[1]铜仁学院农林工程与规划学院,贵州铜仁554300 [2]昆明理工大学现代农业工程学院,云南昆明650500

出　　处：《云南水力发电》2020年第5期46-52,共7页Yunnan Water Power

基　　金：黔教合KY字[2017]319号;黔科合LH字[2017]7318号;国家自然科学基金项目(51569010)。

摘　　要：宽尾墩与阶梯溢流坝联合消能工在宣泄高水头大单宽流量时,阶梯溢流坝面往往因掺气不足而引起坝面产生空蚀空化破坏,基于阿海电站一体化联合消能工,采用三维数值模拟研究不同台阶组合的过渡阶梯对一体化联合消能工坝面掺气特性的影响。结果表明,增设过渡阶梯既有助于增大坝面掺气空腔长度,又可有效增大坝面掺气空腔面积,其中增设首级过渡台阶对增大坝面掺气空腔最为明显,增加过渡阶梯台阶数量可适当增大坝面掺气空腔面积,而对坝面掺气空腔长度影响较小;坝面掺气空腔沿水舌两边缘向中心剖面先迅速减小,然后略有增大,最小掺气空腔在水舍底部每股对冲水流的中心剖面处产生。坝面沿程掺气浓度总体呈减小趋势,但波动较大,其中不设过渡阶梯方案沿程掺气浓度最小值为1%,明显较设过渡阶梯方案为小,不能有效减免坝面产生空蚀空化破坏,其中增设首级过渡台阶对增大阶梯坝面掺气浓度最为明显,增加过渡阶梯台阶数量可适当增大阶梯坝面掺气浓度。When the joint energy dissipator with wide tailed pier and stepped spillway dam discharges high head and large unit width discharge,the stepped spillway dam surface often produces cavitation damage due to insufficient aeration.Therefore,based on the integrated joint energy dissipater of Ahai Hydropower Station,this paper uses three-dimensional numerical simulation to explore the influence of different combination of transition steps on the aerated characteristics of the integrated joint energy dissipater.Results show that adding transitional ladder helps to increase both the dam surface aeration cavity length,and can effectively increase the dam surface aeration cavity area.Adding the first transition step is the most obvious way to increase the aerated cavity area on the dam surface.Increasing the number of transition steps can appropriately increase the area of the aerated cavity on the dam surface,but has little effect on the length of the aerated cavity on the dam surface.The results show that the aerated cavity on the dam surface decreases rapidly along the two edges of the water tongue and then increases slightly.The minimum aerated cavity is generated at the central section of the bottom of the water shed against the flow.The aerated concentration along the dam surface decreases,but fluctuates greatly.The minimum value of aeration concentration in scheme 1 without transition step is 1%,which is obviously smaller than that of scheme with transition step,which can not effectively reduce cavitation damage on dam surface.Among them,adding the first transition step is the most obvious way to increase the air entrainment concentration on the stepped dam surface,and increasing the number of transition steps can appropriately increase the air entrainment concentration on the stepped dam surface.

关 键 词：工程水力学 过渡阶梯 三维数值模拟 掺气空腔 掺气浓度 

分 类 号：TV131.34[水利工程—水力学及河流动力学]