“Y”型汇流区水流结构试验研究

Experiments on flow structure in symmetrical("Y") confluence area

在天然水系和城市排水系统中存在许多干支流交汇,在汇流区水流结构紊乱,严重制约着该区域水沙运动及河床调整,进而影响岸坡稳定及航道水流条件,并且污染物也容易在该区域滞留。鉴于此,通过概化模型试验研究了"Y"型汇流区的水流结构,再运用Tecplot等软件对试验数据作可视化处理。结果表明:汇流区三维流速图存有两个高速区和一个中间低速区;随汇流比增大,支流侧高流速区范围增大,干流侧高速区范围相应减小,同时水流动力轴线汇流点往下游移动。

There are many confluent channels in natural water systems and city drainage systems. In the confluence area, the disordered flow structure has great impact on the movement of flow and sediment as well as river bed adjustment. Consequently, it affects bank slope stability and navigation channel flow conditions. And pollutants are also easily stranded in the area. In view of this, we studied the flow structure in symmetrical （＂ Y＂） confluence area through generalized model, then visualized the ex- perimental data by using Tecplot software. The results showed that there were two high - speed areas and one low - speed area in the three - dimensional velocity figure of confluence area; with the increase of confluence ratio, the tributary~ high - speed area was enlarged while the main stream＇s high - speed area was decreased, meanwhile, the confluence point of flow dynamic axis moved to downstream.