跌坎式底流消力池水力特性三维数值模拟与试验研究

Optimization of Hydraulic Characteristics of Stilling Basin with Step-down Floor by 3-D Numerical Simulation and Physical Model Test

采用三维数值模拟结合物理模型试验的方法,对某水电站表孔、中孔及其末端的跌坎式底流消力池的水流三维流场进行了计算分析和试验研究。分别比较了跌坎高度、消力池深度、跌坎水平长度以及出口侧收缩等对跌坎式底流消力池水流结构及相关水力特征量的影响,优选了水力特征量相对较好的跌坎式消力池结构布置型式,可为工程设计提供参考。

In this research, the three-dimensional flow field of the surface-holes, mid-holes and the stilling basin with step-down floor of a hydropower station was simulated by 3-D numerical simulation and model test. We modi- fied the shape of the step-down floor from four aspects ： the height of the steps, the depth of the stilling basin, the length of the horizontal platform in front of the step-down floor, and the side contraction at the outlet, and compared their effects on the flow structure and the characteristics of the stilling-basin. Results show that all these measures could reduce the bottom velocity and fluctuating pressure on the floor. In particular, increasing the flat length obvi- ously reduces fluctuating pressure and the velocity at the drop location of jet flow, but has large construction work- load; while side contraction at the outlet effectively changes th velocity and fluctuating pressure, and in the meantime has less neering design. e horizontal and longitudinal distribution of bottom workload. The result could be a reference for engi-neering design.