承压式溢流井淤积实验研究

为研究承压式溢流井的淤积规律,通过模型实验实测了井底面速度分布,并据此计算出相应的床面切应力。根据相似准则进行泥沙沉积实验,得到不同工况下的泥沙沉积分布。结果显示,溢流井内流场在恒定流工况时由一对大致对称的椭圆形涡流组成,而且涡流周围区域的紊动能及切应力均较大,其冲刷力亦较强,泥沙难以沉积下来。涡流中心和四周角落区域的切应力及冲刷力较小,有大量泥沙沉积。分析比较泥沙沉积位置与切应力分布,即可估计出模型沙的临界切应力值为0.05～0.07N/m2。

Experimental study on sedimentation of pressurized CSO chamber

In order to research the sedimentation regulation of pressurized combined sewer overflow（CSO） chamber, the velocity distributions of well bottom were measured and the bed shear stress （BSS） were correspondingly computed. According to the similarity criteria, sedimentation distributions of different conditions were obtained by sedimentation experiment. The results show that the flow field consists of two approximately symmetrical elliptic eddy current under steady flow condition. The turbulent kinetic energy and shear stress are strong as well as the scouring force around the eddy current, where sedimentation occurs hardly. On the contrary, there are large amount of sedimentation in the eddy current centre and corner because of less shear stress and scouring force. The critical BSS is estimated to be 0.05-0.07 N/m2 by comparing sedimentation distribution and shear stress distribution.