反弧阶梯溢洪道水力特性

为提高大单宽流量阶梯溢洪道消能率和增加掺气,提出一种新型反弧阶梯溢洪道,即将传统直角阶梯的水平面改为反弧面。通过物理模型试验,对反弧形阶梯的流态、掺气发生位置和消能率进行了研究。结果表明,在试验条件范围内,反弧阶梯流态可分为跌落流、挑射流、过渡流、滑行流4 种,在单个阶梯长度和高度相同时,反弧阶梯掺气发生位置是直角阶梯的0. 5 ~0. 8 倍,反弧阶梯消能率比直角阶梯最大增加约9%。

Hydraulic characteristics of a reverse arc-stepped spillway

In order to improve the energy dissipation rate and increase the aeration, a new type of reverse arc-stepped spillway was proposed, in which the horizontal plane of the traditional right-angle step was changed into a reverse arc surface. The flow pattern, aeration location and energy dissipation rate of the reverse arc step were studied by physical model tests. The results show that in the range of test conditions, the flow patterns of the reverse arc step can be divided into four kinds, which are nappe flow, ejection flow, transition flow and skimming flow. When the length and height of a single step are the same, the aeration position of the reverse arc step is 0. 5 to 0. 8 times of that for a right-angle step, and the energy dissipation rate of reverse arc step is about 9% higher than that of a right-angle step.