复杂无压隧洞输水过程三维数值模拟与方案优选

运用基于流体体积（VOF）法的三维缸占双方程紊流模型模拟了无压引水隧洞水气两相流紊流流场，近壁面采用考虑糙率影响的壁函数法进行处理．以某复杂长距离无压引水隧洞的输水过程为例，模拟了3种方案的断面平均过水面积、流量、流速和气压的变化，实现了多方案的比选结果表明，3种方案水流均能顺利通过隧洞；方案二水流到达隧洞出口的时间最短：方案二的断面平均过水面积、流量、流速和气压均优于方案一；方案三与方案二差别较小，综合考虑过流能力及成本因素，方案二为最优方案．通过与某水库放水兼放空洞水深实测数据及采用传统水力学方法计算的经验值的对比分析，平均相对误差分别为5．01％和0．96％，验证了模型的可靠性．

3D Water Delivery Process Numerical Simulation and Scheme Optimization for Complex Free-Flow Tunnel

Based on volumn of fluid （VOF） method,the κ-εturbulence model was used to simulate the 3D water-air two- phase flow for free-flow tunnel. The wall function was applied near tunnel wall. Take the water delivery process of a complex long-distance free-flow tunnel as an example,the average flow area,discharge,velocity,and pressure of flow area were obtained to optimize the schemes. The results show that water can across the tunnel for each scheme. The time across the tunnel of the second scheme is the shortest and the results are superior to those of the first one. The characteristic of the third one is similar to those of the second one. The second scheme is chosen as the optimal one considering flow capacity and cost. The reliability of proposed model is verified by the data of the water depth in the drainage and emptying tunnel of a reservoir as well as the experimental result using hydraulic method. The average relative errors are 5.01% and 0.96%, respectively.