岸边溢洪道侧面挑入消力池消能方式研究

Study on energy dissipation method- lateral jetting of side spillway into plunge pool

本文提出了一种岸边溢洪道从侧面分散挑射出流,利用与之平行布置的已有消力池来消能的布置形式,采用模型试验和数值模拟的方法对溢洪道的水力特性以及消力池内的水流流态等进行了研究。结果表明,在适当的位置取消侧墙,并配合底板的适当倾斜,可使部分水流从侧面沿程均匀跌入消力池,溢洪道另一侧边墙末端采用圆弧收缩至消力池边墙处,可使其余水流从跌射水流上方挑射进入水力池,从而在消力池内形成一"∩"形入射水舌,使溢洪道出射水流充分拉伸扩展,分散进入消力池,避免对消力池底板造成较大的冲击。采用这种布置形式,既不影响其它泄洪建筑物泄洪时消力池的正常运行,又充分利用了已有消力池的后半部分供溢洪道消能,可大大节约工程投资。

This article describes a new layout of side spillway that scatters water flow laterally into an existing parallel-arranged plunge pool to achieve energy dissipation. Hydraulic model tests and numerical simulations were used in the study focusing on analysis of hydrauliccharacteristics of the flow over spillway and the flow patterns in plunge pool. The results show that removal of one part of the sidewall at an appropriate location combined with a sloping pool bottom can provide a condition for a certain portion of the flow to fall laterally into the pool uniformly along its way. At the opposite sidewall of spillway, a circular-curve contraction is adopted and extends downstream up to its joint with the pool sidewall. This contraction helps the rest portion of flow to jet into the pool along a path over the lateral nappe. Thus, the total jet nappe takes a shape of ＂∩ ＂ and it is fully stretched and expanded, then dispersed up to its pool plunging location, so as to avoid excessive impact pressure on the pool bottom. This spillway layout can not only produce little affect on the normal running of plunge pool in the case of other releasing structures in operation, but make a full use of the rear part of the existing plunge pool for dissipation of more energy, which could lead to a great saving of project investment.