摘要
底流消能工中水流紊动剧烈、大量掺气,面临着空化空蚀问题。为研究底流消能工气体迁移扩散运动与水流结构相互作用机理,采用水力学试验开展研究,对底流消能工进行水流结构划分,通过调整流量与尾坎高度,改变入射Fr数及跃后水深与跃前水深比,分别测出消力池内掺气浓度值,并分析数据研究水流结构区气体的运动机理,得到消能工内掺气浓度分布规律。结果表明,掺气浓度随Fr数的增大而增大,随跃后水深与跃前水深比的增大而减小;各水流结构区掺气浓度沿程衰减,纵向衰减速率附壁射流区>射流扩散区>稳定区;横断面掺气浓度呈"双钟形"分布规律;竖向掺气浓度附壁射流区变化曲线呈凹型递增、射流扩散区先增后减、稳定区递减规律。水流结构区交界处形成气体交换带,是气体发生交换的主要区域,掺气浓度在气体交换带处达最大值。该研究可供底流消能工的防空化空蚀参考。
Underflow energy dissipator has been challenged cavitation caused by the violently turbulent and aerated flow.To delve into the interaction mechanism between gas migration & diffusion and flow structure in the underflow energy dissipator,a study is conducted based on a hydraulic test to divide the flow structure and to measure concentrations of aeration on each section in the stilling pool by changing discharge and height of flip bucket.And then the movement mechanism of air in the water flow structural region have been analyzed to obtain the law of aerated concentration distribution in the stilling pool.The results show that the aerated concentration increases as the Fr increases while decreases as the end sill height increases;Aerated concentration in the flow structural regions falls out along the way,and the longitudinal attenuation rate at the wall-attached jet area is greater than other area.The cross section aerated concentration appears in a "low on the ends but high in the middle" distribution.Vertical aerated concentration in the wall-attached jet area shows an increasing concave trend while that in the jet dispersion area increases first and then decreases,and that in the stable area is on the decline.A air exchange zone formed by the interface of flow structural areas is a primary place where air exchanges,which the aerated concentration is the maximum.The research can provide reference for prevention of cavitation in underflow energy dissipator.
作者
王睿齐
王海军
沈春颖
陈鹏宇
邹亦云
WANG Rui-qi;WANG Hai-jun;SHEN Chun-ying;CHEN Peng-yu;ZOU Yi-yun(Faculty of Electric Power Engineering,Kunming University of Science and Technology,Kunming 650500,China)
出处
《水电能源科学》
北大核心
2021年第5期113-117,共5页
Water Resources and Power
基金
国家自然科学基金项目(51669007,52069009)。
关键词
底流消能工
水流结构
模型试验
掺气浓度
underflow energy dissipator
water flow structural region
model test
aeration density
