排水系统入海口新型消能工

A new type of energy dissipator for coastal outfall of a drainage project

通过实体模型试验研究了某排水系统入海口水工建筑物的水力性能,设计提出一种新型的墩栅涡流室消能工。该新型消能工的水力特点是:流出排水隧洞的高速水流大部分通过进口墩栅空隙流入涡流室,小部分在进口墩栅前发生水跃后扎入涡流室中产生强烈的顺时针漩涡,通过水跃、墩栅的阻力和涡流室漩涡的共同作用消能,并将来流的动能转换为势能,之后,涡流室中的大部分水流在重力作用下通过出口墩栅空隙流向下游,其余水流从墩栅顶部溢流。这种新型的墩栅涡流室不仅消能效果良好而且出流均匀,并容许各种杂物如石块、泥沙等自由通过,避免涡流室中发生严重的淤积。

The hydraulic performance of hydraulic structures at coastal ouffall of a drainage project was studied by physical model tests. A new structure of energy dissipation, called the baffle-block vortex chamber, was designed. Each of the vortex chambers was bordered by two rows of baffle blocks. Most of the high- velocity water flow from drainage tunnel flowed into vortex chambers through the gaps between the baffle blocks. Hydraulic jumps caused by the other part of the water flow oceurred right before the first row of baffle blocks and their nappe plunged into vortex chambers, causing a strong clockwise vortex underwater. By the coaction of the hydraulic jumps, resistance of baffle blocks, and vortexes, the kinetic energy of the inflow was mainly dissipated and the remained was converted into the potential energy. Then most of the water in vortex chambers flowed out of the chambers toward downstream, and the other part flowed over the chambers into a spillway. The new structure is of good effect of energy dissipation with uniform outflow, and it permits some matters, such as stones and sediment to pass through freely, and thus avoids serious deposition in vortex chambers.