同比例改变过渡台阶尺寸对联合消能工水力特性影响研究  

Experimental Research on the Change of the Dimension with the Same Proportion of Transitional Step on the Hydraulic Characteristics of Combined Dissipation

作　　者：李书曌 杨具瑞[1] LI Shu-zhao;YANG Ju-rui(School of Modern Agricultural Engineering,Kunming University of Science and Technology,Kunming 650504,Yunnan Province,China)

机构地区：[1]昆明理工大学现代农业工程学院,云南昆明650504

出　　处：《中国农村水利水电》2018年第8期166-171,175,共7页China Rural Water and Hydropower

基　　金：国家自然科学基金"阶梯溢流面与WES曲面的衔接方式对宽尾墩+阶梯溢流坝+消力池消能工水力特性的影响研究"(51569010)

摘　　要：联合消能工水力特性的研究对改善高速水流冲蚀以及空蚀空化等问题具有实际的指导意义,然而数值模拟比物理模型更省时省费用的同时,对阶梯流流坝面的空化、空蚀问题很难进行模拟。为了进一步完善联合消能工,结合阿海电站水工模型对同比例改变过渡台阶尺寸的Y型宽尾墩+阶梯溢流坝+消力池联合消能工进行了实验研究。实验研究发现,单个台阶长度以及台阶处与空气接触面积不同时,单位空腔面积越大,平均掺气浓度亦逐渐增大,掺气越充分。各实验方案沿程时均压强总体变化基本一致。同比例增大过渡台阶尺寸(方案三、方案四)有利于水流能量的耗散、减小高速水流对反弧段的冲刷。同比例扩大过渡台阶尺寸(方案四)可以有效地进一步降低台阶壁面发生空蚀破坏的风险。在同比例改变过渡台阶尺寸时,也要考虑过渡台阶与WES曲线相衔接处尺寸变化,不宜采用尺寸过小的台阶与之相衔接。控制其他变量相同时,同比例扩大过渡台阶尺寸(方案四)优于其他实验方案,对整体联合消能方式中掺气状况、对减小反弧段的冲刷、降低台阶面空蚀空化影响等方面均有积极作用。The study of hydraulic characteristic of combined energy dissipation is of practical significance to improving the erosion and cavitation of high-speed flow. Numerical simulation is more time-efficient and cost-saving than the physical model,but it is also difficult to simulate the cavitation of stepped spillway face. This paper makes an experimental study of the change of the dimension with the same proportion of transitional step on the hydraulic characteristics of combined dissipation. The study shows that when the length of a single step and the contact area of the step with the air are different,the larger the unit cavity area is,the larger the average aeration concentration is,the more the aeration is. The overall changes in the mean pressure along the experiment program are basically the same. Increasing the size of the transition steps in the same proportion（ Scheme 3,Scheme 4） is beneficial to the dissipation of water flow energy and the reduction of high-velocity flow to the erosion of the anti-arc section. Expanding the size of the transitional step with the same ratio（ Scheme 4） can effectively reduce the risk of cavitation damage occurring to the stepped wall surface. When the size of the transitional step in the same proportion is changed,the size change of the transitional step and the WES curve should also be taken into consideration. It was not appropriate to use a step with a small size to converge with it. When the control of other variables is the same,the size of the same-scale enlarged transition step（ Scheme 4） is better than other experiment schemes.

关 键 词：水工水力学 过渡台阶 掺气空腔长度 负压 消能率 阶梯溢流坝 

分 类 号：TV321[水利工程—水工结构工程] TV322