大盈江四级水电站溢流坝水力特性研究

Study on Hydraulic Characteristics of Spillway Dam of Dayingjiang Fourth-Level Hydropower Station

文章针对大盈江四级水电站设计阶段提出的两种溢流坝布置方案(方案一:溢流坝+右侧泄洪冲沙底孔;方案二:溢流坝+左侧泄洪冲沙闸+右侧泄洪冲沙底孔)进行了计算流体力学数值模拟(CFD),结合水工模型试验结果与CFD数值模拟结果,分析了溢流坝两种布置方案的流态分布规律和消能防冲效果。计算结果表明,在流态规律和流速分布及消能防冲效果方面,方案一优于方案二;方案二较方案一更有利于库区排沙减淤,泄流能力较强。通过控制闸孔启闭模式可调整方案二相应出流流态,能较好地适应大盈江高含沙量的水流条件。

The paper conducts computational fluid dynamics(CFD)numerical simulations on two overflow dam layout schemes proposed during the design phase of the Dayingjiang Fourth-Level Hydropower Station:Scheme One,comprising an overflow dam with sand flushing bottom orifices on the right side,and Scheme Two,comprising an overflow dam with sand flushing gates on the left side and sand flushing bottom orifices on the right side.By combining the results of hydraulic model tests with CFD numerical simulation results,the paper analyzes the flow distribution patterns and energy dissipation and erosion prevention effects of the two overflow dam layout schemes.The results indicate that Scheme One is superior to Scheme Two in terms of flow patterns,velocity distribution,and energy dissipation and erosion prevention effects.However,Scheme Two is more advantageous for sediment discharge and reduction in the reservoir area,with stronger discharge capacity.By controlling the opening and closing modes of the gates,Scheme Two can adjust the corresponding outflow flow patterns,making it better suited to the high sediment content flow conditions of the Dayingjiang River.