摘要
引水时泥沙含量过高会导致一系列工程问题,为解决多泥沙河流引水时的水沙分离问题,常在渠首处设置排沙设施。旋流排沙渠道作为一种渠道排沙新技术,其综合性能和排沙效果是其推广应用的关键所在。本文采用试验研究和数值模拟相结合的方法,对旋流排沙渠道内水流的水力特性和排沙特性进行了分析。首先,采用物理模型进行试验,获得相应的水力参数和截沙率;其次,通过试验所得参数验证数值模拟的准确性,其中流速、水面线等参数数值模拟结果与试验值一致,数值模拟能够反映旋流排沙渠道内水流的运动状态;最后,结合模型试验和数值模拟对旋流排沙渠道的水力特性和排沙特性进行综合分析。结果表明:起旋室流态随渠道来流量的增加呈自由流、临界流及淹没流的流态演变序列;在淹没流流态下,排沙洞内能形成有利于泥沙悬浮卷扬的旋转水流,且对引水渠道内的流态影响很小;随着上游渠道水深增加,排沙洞的分流比呈非线性规律减小,在上游渠道内相对水深为0.97时,排沙洞的分流比仅为6.07%;上游渠道内相对水深为0.21时,排沙洞内最大流速较渠道平均流速增大了175%,对粒径为0.075~3.000 mm泥沙的截沙率达93.7%。综上所述,旋流排沙渠道是一种高排沙率、低耗水量的渠道排沙技术,成果有利于丰富引水工程中的水沙分离技术,为解决渠道泥沙淤积问题提供了新思路。
Excessive sediment content during water diversion will lead to a series of engineering problems.In order to solve the problem of water and sediment separation during water diversion of sediment-laden rivers,sediment discharge facilities are often set at the channel head.As a new channel sediment discharge technology,the comprehensive performance and sediment discharge effect of the desilting channel with swirling flow are the key to its popularization and application.In this paper,the experimental study and numerical simulation are used to analyze the hydraulic characteristics and sediment discharge characteristics of the flow in the desilting channel with swirling flow.Firstly,according to the physical model,the experiment was carried out to obtain the corresponding hydraulic parameters and sand interception rate.Secondly,the accuracy of the numerical simulation is verified by the parameters obtained from the experiment.The numerical simulation results of the parameters such as flow velocity and water surface profile are consistent with the experimental values,and the numerical simulation can reflect the movement state of the flow in the desilting channel with swirling flow.Finally,combined with the model test and numerical simulation,the hydraulic characteristics and sediment discharge characteristics of the desilting channel with swirling flow are comprehensively analyzed.The results show that the flow pattern in the swirling flow generator is in the evolution sequence of free flow, critical flow and submerged flow with the increase of channel inflow. Under the submerged flow pattern, the rotating flow can be formed in the sediment discharge tunnel, which is beneficial to the suspension and up-lifting of sediment and has little influence on the flow pattern in the diversion channel. With the increase of the water depth in the upstream chan-nel, the diversion ratio of the sediment transport pipe decreases nonlinearly. When the relative water depth is 0.97, the diversion ratio of the sedi-ment discharge tunnel is only 6.07%. When the relative water depth is 0.21, the maximum velocity in the desilting tunnel is increased by 175% compared with the average velocity in the channel, and the sediment interception rate for the sediment of the particle size of 0.075 mm~3.000 mm reaches 93.7%. In summary, the desilting channel with swirling flow is a channel sediment discharge technology with high sediment discharge rate and low water consumption. The results enrich the study of water and sediment separation technology in water diversion projects, and provide a new idea for solving the problem of channel sediment deposition.
作者
南军虎
高欢
汪超群
马康宁
罗涵
刘一安
李伟
NAN Junhu;GAO Huan;WANG Chaoqun;MA Kangning;LUO Han;LIU Yian;LI Wei(College of Energy and Power Eng.,Lanzhou Univ.of Technol.,Lanzhou 730050,China;State Key Lab.of Eco-Hydraulics in Northwest Arid Region of China,Xi’an Univ.of Technol.,Xi’an 710048,China)
出处
《工程科学与技术》
EI
CSCD
北大核心
2022年第6期116-123,共8页
Advanced Engineering Sciences
基金
国家自然科学基金项目(52069011
51509123)
西北旱区生态水利国家重点实验室开放基金项目(2019KFKT–9)
甘肃省教育厅产业支撑计划项目(2021CYZC–27)
甘肃省优秀研究生“创新之星”项目(2021CXZX–474)。
关键词
旋流排沙渠道
流态
分流比
截沙率
desilting channel with swirling flow
flow pattern
split ratio
sediment trapping efficiency
作者简介
南军虎(1985—),男,副教授,博士.研究方向:水工水力学和生态水力学.E-mail:nanjh08@126.com。
