多级跌坎跌水复氧过程及影响因素试验研究  

EXPERIMENTAL STUDY OF THE REOXYGENATION PROCESS AND ITS INFLUENCING FACTORS OF MULTISTAGE FALLING-DROP

作　　者：王琼[1,2] 李乃稳[1,2] 王月[1,2] 李龙国[1,2] 

机构地区：[1]四川大学水力学与山区河流开发保护国家重点实验室,成都610065 [2]四川大学水利水电学院,成都610065

出　　处：《环境工程》2016年第11期49-54,共6页Environmental Engineering

基　　金：国家自然科学基金(51009102;51179113)

摘　　要：跌坎作为连接水流上下游的主要措施,水流在跌落过程中其溶解氧迅速增加。以水体氧亏率为指标,研究多级跌坎水流流态为自由跌落水流时的水体复氧过程和机理,结果表明:可将水流自跌坎跌落至下一级跌坎上的整个区域分成水舌空中跌落区(I)、回水区(II)、冲击与水跃区(III)和水流平顺区(Ⅳ),水舌空中跌落区和冲击与水跃区为复氧的主要区域,水体在空中与大气充分接触以及水流流动过程中的自掺气是水体复氧的主要途径;水流流经跌坎时的氧亏率随着单级跌坎高度、多级跌坎级数、跌坎总坡度和流量的增加而增加,与水流紊动程度呈正相关,随着跌坎雷诺数的增大而增加。Falling-drop is one of the main measures to connect the upstream with the downstream,and the dissolved oxygen in water increases rapidly during the falling of flow. With the oxygen deficit recovery rate as the indicator,the process and mechanism of the reoxygenation in the water were experimentally studied. The study showed that for the whole area of flow falling from the superior drop to the next drop,it could be divided into four main areas as following： The free falling area in the air（ I）,the backwater area（ II）,the water impact and hydraulic jump area（ III） and the smooth-going area（ Ⅳ）. The main areas of reoxygenation were the free falling area in the air（ I） and the water impact and hydraulic jump area（ III）. The main ways of reoxygenation were the full contact between the flow and air and the self-aeration in the flowing process. The oxygen deficit recovery rate increased as the increasing of the single drop height,the number of steps drops of multistage falling-drop,the overall slop of multistage falling-drop and the waterfall flow discharge. The oxygen deficit recovery rate was also positively related to the intensity of flow turbulence and flow Reynolds number.

关 键 词：自由跌落水流 水体复氧 多级跌坎 氧亏率 影响因素 复氧过程 

分 类 号：X52[环境科学与工程—环境工程]