湍流模型在肘形进水流道三维流场数值模拟中的适用性研究

Applicability of Turbulence Model in 3-D Flow Filed Numerical Simulation of Elbow Inlet Conduit

为找到可准确模拟低扬程泵站肘形进水流道水流流动的湍流模型,在对肘形进水流道进行网格无关性分析的基础上,选用S-A、Standardκ-ε、RNGκ-ε、Realizableκ-ε、Standardκ-ω、SSTκ-ω和RSM等7种常用湍流模型分别对肘形进水流道三维湍流流动进行数值模拟,并从流道水头损失和流态两个方面与流道模型试验结果进行比较。结果表明,不同湍流模型满足网格无关性所需的网格数量不同,RNGκ-ε、Realizableκ-ε和S-A湍流模型数值模拟的水力损失与模型试验结果的相对误差分别为1.01%、7.07%、9.09%,RNGκ-ε与Realizableκ-ε湍流模型计算得到的流场几乎完全相同,建议在对肘形进水流道三维湍流流动进行数值模拟时优先考虑采用RNGκ-ε湍流模型。研究成果可为进水流道三维湍流流动数值模拟的模型选择提供依据。

In order to find the turbulence model which can be used to accurately simulate the flow in elbow inlet con duit of low head pumping station, based on the grid independent analysis of the elbow inlet conduit, sevens common turbulence models, such as S-A, Standard κ-ε, RNG κ-ε, Realizable κ-ε, Standard κ-ω, SST κ-ω, and RSM, were chosen to simulate the flow in elbow inlet conduit respectively. And then the simulation results were compared with the model test from the aspects of hydraulic loss and flow pattern. The results indicate that different turbulence model needs different grid numbers to meet the grid independent requirement. The hydraulic loss relative errors of numerical simulation results and model test are 1.01%, 7.07% and 9; 09% for the RNG κ-ε turbulence model, Realizable κ-ε turbulence model and S- A turbulence model, respectively. The flow fields of the elbow inlet conduit simulated by the RNG κ-ε turbulence model and Realizable κ-ε turbulence model are mostly the same. It is suggestion that RNG κ-ε turbulence model should be the first choice when the flow of elbow inlet conduit is simulated. The research results can provide a basis for model selection of numerical simulation of three-dimensional turbulent flow in the inlet conduit.