密云水库第一溢洪道数值模拟与物理模型试验成果分析及应用

Numerical simulation and model test of the first spillway of Miyun Reservoir results analysis and application

第一溢洪道是密云水库主要泄水建筑物之一,鉴于第一溢洪道改建工程设计方案需综合考虑泄流能力、现状溢洪道利用及施工难度等因素,设计过程中采用了三维数值模拟与物理模型试验相结合的方式,对第一溢洪道的主要水力特性进行研究。本次数模仿真计算基于fluent软件,采用标准k-ε双方程紊流模型,结合VOF方法对第一溢洪道进行数值模拟,模拟了梯形泄槽和矩形泄槽等多个组合方案下水流流场内部特性。试验结果得出:在设计水位157.5 m,校核水位158.5 m下,梯形泄槽方案的泄流能力不满足设计要求,矩形泄槽方案的泄流能力满足设计要求且高于设计期望值。通过建立水工物理模型,开展了溢洪道泄流能力、水流流态、布置及消能防冲等试验,分析了试验成果,并将试验成果应用于工程设计方案的优化中,同时为水库的防洪调度取得可靠的基本资料,以确保密云水库防洪安全。

The first spillway is one of the main discharge structures of the Miyun Reservoir,suggested demolition and reconstruction.Considering that the design scheme of the reconstruction project of the first spillway needs to take into account the factors of discharge capacity,current spillway utilization,construction difficulty,etc.,in the design process,the main hydraulic characteristics of the first spillway are studied by means of 3D numerical simulation and physical model test.Based on fluent software,the numerical simulation of the first spillway is carried out by using the standard k-εtwo-equation turbulence model and the VOF method,the internal characteristics of the flow field under several combined schemes such as trapezoidal drain and rectangular drain are simulated.The test results show that the discharge capacity of trapezoidal discharge tank is not satisfied with the design requirement at the design water level of 157.5 m and the check water level of 158.5 m,while the discharge capacity of rectangular discharge tank is satisfied with the design requirement and higher than the design expectation.Through the establishment of hydraulic physical model,the spillway discharge capacity,flow pattern,configuration,energy dissipation and scour prevention experiments are carried out,and the test results are analyzed,the test results are applied to the optimization of the project design scheme,and reliable basic data are obtained for the reservoir flood control operation to ensure the flood control safety of Miyun Reservoir.