三种紊流模型模拟溢流坝泄流精度的对比分析

Comparative Analysis of Simulation Flow Accuracy for Overflow Dam Using Three Turbulence Models

为研究不同紊流模型对溢流坝泄洪数值模拟的适用性和准确度,采用标准κ-ε模型、RNGκ-ε模型及大涡模拟(LES)模型等3种经典紊流模型对某溢流坝泄流过程进行数值模拟;同时,将数值模拟出的溢流坝坝面的水流流态、流速及坝面压强等溢流坝泄流过程的重要水力指标结果与物理模型试验结果进行对比分析。结果表明,RNGκ-ε模型对溢流坝泄流的流态模拟效果最好,与物理模型试验结果最为一致;LES模型对坝面水流流速、坝面压强及空化数的模拟效果最好;采用标准κ-ε模型模拟出的各个指标精度最低。因此,针对溢流坝泄流过程数值模拟,应优先采用RNGκ-ε模型和LES模型。

In order to study the applicability and accuracy of different turbulent models for the numerical simulation of spillway flow, the Standard κ-εmodel, RNG κ-ε model and Large Eddy Simulation （LES） model were used to simulate the flow process of overflow dam. Meanwhile the hydraulic indexes （i. e. , flow regime, velocity and pressure distribu- tion） achieved by these turbulent models were made a contrast to the data from the physical model test. The results show that the flow regime obtained by the RNG ^-e model has the best simulation effect and is most closely to the physical model test. The LES model is superior to the other two in simulating the velocity, pressure and cavitation number simu- lation. The precision of the Standard κ-ε model is the worst. Therefore, the RNG κ-ε and LES models should be preferred to use for the simulation of spillway flow.