摘要
黑龙江等平原河流水域宽广,常形成分汊河道形态,汊道两侧往往具有宽阔的河漫滩,河道成复式断面形态。为探究以黑龙江为代表的复式分汊河道水流运动特性,以流量和主槽深度作为试验变量,设计了清水冲刷的对称分汊水槽试验。试验所得水流运动特性,对预测黑龙江滩洲的演变及稳定发育提供一定的理论依据。分析表明,水流纵向、横向流速平面分布主要受分汊形态影响,水流横向流速分布有“小水作弯,大水趋直”的特点;断面流速横向分布与水槽断面形态和位置有关,主槽对水流的约束作用和滩槽的相互作用对水流的结构造成影响,分流段水流有“底部作弯,顶部趋直”的特点。在江心洲洲头两侧存在纵向及横向流速的高值区,洲尾有流速低值区,故应该重点关注江心洲洲头两侧冲刷和洲尾淤积。
The plain rivers such as Heilongjiang River often form branched river channels due to wide water areas.Both sides of the branched channels usually have wide floodplains,which together form compound sections.To explore the characteristics of the flow motion of the main stream of Heilongjiang River,the discharge and main channel depth of river are selected as experimental variables,an experiment of a symmetrical braided channel eroded by clear water is designed.The flow characteristics summarized on the basis of experimental phenomena provide a theoretical basis for predicting the evolution and stable development of Heilongjiang River s beaches.The analysis shows that,(a)the planar velocity distribution of the longitudinal and horizontal flow is mainly affected by the shape of the braided boundary,and the horizontal flow velocity distribution has the characteristics of small water bends and large water straightens;and(b)the horizontal distribution of cross-sectional velocity is related to the shape and position of the cross section of the flume,the restraining effect of the main channel on the flow and the interaction of shoals and troughs have an impact on the flow structure,and the sectional flow appears bent at the bottom and straight at the top.The high-value areas of longitudinal and horizontal velocity are presented on both sides of the head of the sandbar,and the low-velocity areas are presented at the end of the sandbar,therefore,the attention should be paid to the erosion on both sides of the head of and the silts on the end of the central sandbar.
作者
李润祥
朱殿芳
范钟轶
罗亚军
刘涛
张婧
郭志学
LI Runxiang;ZHU Dianfang;FAN Zhongyi;LUO Yajun;LIU Tao;ZHANG Jing;GUO Zhixue(State Key Laboratory of Hydraulics and Mountain River Engineering,Sichuan University,Chengdu 610065,Sichuan,China;Chengdu Municipal Engineering Design and Research Institute,Chengdu 610023,Sichuan,China;Xihua University,Chengdu 610039,Sichuan,China)
出处
《水力发电》
CAS
2021年第9期123-127,共5页
Water Power
基金
国家重点研发计划项目(2018YFC0407301)。
关键词
复式分汊河道
水槽试验
水流特性
黑龙江
compounding and branching channel
flume model experiment
flow characteristics
Helongjiang River
