阶梯溢流坝过渡台阶体型水力特性研究

鉴于阶梯溢流坝采用台阶消能具有较好的消能效果,且阶梯溢流面与WES曲面的衔接处常采用过渡台阶可改善水流流态,采用数值模拟计算与模型试验相结合的方法,分析了四种不同过渡台阶体型下的阶梯坝面水流流态、流速、掺气起始点位置、掺气浓度和消能率等水力特性。研究结果发现,方案2、3、4在流态方面稳定,流速方面有一定的减小,消能率方面显著提高,但方案2、3在掺气起始位置方面略微下降。为此对方案4内凹型的过渡台阶的设置进行3种工况下的试验研究,证明其具有较好的工程价值和研究意义。

Study on Hydraulic Characteristics of Transitional Steps of Stepped Overflow Dam

The step energy dissipation in stepped overflow dam has better energy dissipation effect. Transition steps are often used at the junction of the stepped overflow surface and the WES surface to improve the flow pattern. In this study, a combination of numerical simulation calculation and model test is used to analyze the water flow characteristics, flow velocity, aeration start point position, aeration concentration and energy dissipation rate of the step dam surface with four different transition step types. The results show that the schemes 2, 3 and 4 are stable in terms of flow characteristics, there is a certain reduction in flow velocity, and the energy dissipation rate is significantly increased, but schemes 2 and 3 have slightly decreased in the initial position of aeration. In addition, the experimental research on the setting of the concave step in the fourth scheme is carried out under three working conditions, which proves that it has good engineering value and research significance.