中文摘要：

宽尾墩与台阶溢流坝联合消能在我国水利工程中得到广泛应用。采用有限体积法离散求解,辅以RNG k-ε湍流模型,引入水汽两相流的VOF模型,利用几何重建格式的非恒定流迭代求解生成自由水面,对几何体型采用结构化网格相结合进行处理,从库区到消力池进行了水气两相流的数值模拟。通过模拟其三维流场,得到了整体水流流态、墩后水翅、断面水深等水力特性,重现了抛物线型水气交界面,并将模拟得到水深、消力池底面流速、消力池底板压力与实验数据进行了比较,平均分别误差分别为：#3表孔左边水深7.1%,右边为7.4%;#3表孔底面流速为5%;#1表孔消力池底板压力7.6%,#3表孔消力池底板为6.6%。

英文摘要：

Flaring pier and stepped spillway for joint energy dissipation are widely adopted in China as flood releasing structures. This paper describes numerical simulations of water vapor two-phase flow in the region from reservoir area to stilling pool, using a finite volume method for discretization combined with a VOF model and RNG turbulence model. The numerical model adopts a geometry reconstruction technique for free surface iteration through unsteady flow solution on a structured grid. The simulations show overall flow patterns and flow parameters of water wings, water depth, etc., and reproduce the water surface of parabolic shape. Calculations of water depth, and flow velocity and pressure on the stilling pool bottom, were compared with experimental data. The average errors are 7.1% and 7.4% in the water depths on left and right sides of surface spillway No. 3 respectively, 5% in the velocity near the bottom of surface spillway No.3, and 7.6% and 6.6% in the pressure on stilling pool bottom at the outlets of tunnel No.1 and No.3 respectively.