拱坝挑流坎消能特性数值模拟研究

Numerical Simulation of Energy Dissipation by Flip Bucket of Arch Dam

针对尚甘尼拱坝挑流消能的问题,传统的水工模型试验方法受成本影响,其试验方案数量有限。为此,采用Flow-3D流体计算软件,基于RNGκ-ε湍流模型及VOF方法,建立了拱坝挑流消能计算模型,同时,结合物理模型试验结果,率定模型参数。在此基础上,对不同工况挑流坎泄流进行了三维数值计算,通过分析挑流水舌流态及挑射距离、下游河道流速,进一步研究了拱坝挑流消能的特点及效果。结果表明,采用Flow-3D流体计算软件的RNGκ-ε湍流模型及VOF方法可用以研究拱坝挑流消能问题;连续式挑流坎流态连续,消能效果较差,差动式挑流坎水流分散,掺气增加,相较连续式挑流坎挑距减少,消能效果更好;差动式挑流坎间距越大,消能效果越好。研究成果可为尚甘尼拱坝确定最优挑流消能方案提供依据,也可为类似拱坝挑流坎设计提供参考。

The traditional hydraulic model test method is affected by the cost,and the number of test schemes is limited.Based on RNGκ-εturbulence model and VOF method,the calculation model of flip flow energy dissipation of arch dam is established by using FLOW-3 Dfluid calculation software.Meanwhile,the model parameters are calibrated according to the physical model test results.On this basis,the three-dimensional numerical calculation is carried out for the discharge of flip bucket under different working conditions.By analyzing the flow pattern,ejection distance and downstream river velocity of the flip bucket,the characteristics and effects of energy dissipation of arch dam are further studied.The results show that the RNGκ-εturbulence model and VOF method of FLOW-3 Dfluid calculation software can be used to study the energy dissipation problem of arch dam;The flow pattern of continuous flip bucket is continuous,and the energy dissipation effect is poor.The water flow of differential flip bucket is dispersed and aeration is increased.Compared with continuous flip bucket,the flip distance is reduced and the energy dissipation effect is better;the larger the distance between differential flip bucket is,the better energy dissipation effect is.The research results can provide the basis for determining the optimal scheme of flip bucket energy dissipation of Shangganni arch dam,and can also provide reference for the design of flip bucket of similar arch dam.