虹吸式出水流道水力性能数值计算湍流模型适用性

为寻求适用于大型低扬程泵站虹吸式出水流道水力性能数值计算的湍流模型，首先采用透明流道模型对某低扬程泵站虹吸式出水流道进行了试验研究，测试了流道水头损失并分析了流道内流态; 在网格无关性分析的基础上，选择常用的一方程湍流模型(S-A湍流模型)、二方程湍流模型(k-ε湍流模型、k-ω湍流模型)及Reynolds Stress湍流模型分别对该虹吸式出水流道水力性能进行了三维湍流流动数值计算，并将计算结果与模型试验结果进行比较。结果表明:与一方程湍流模型和Reynolds Stress湍流模型相比，二方程湍流模型在虹吸式出水流道水头损失的计算中更具优越性，采用Standard k-ε，Realizable k-ε和SST k-ω等3种二方程湍流模型计算得到的流道水头损失相对误差小于3%，其中，Standard k-ε湍流模型计算得到的流场与模型试验结果最吻合。

Applicability analysis of turbulence model for numerical calculation of hydraulic performance of siphon outlet conduit

In order to find a turbulence model suitable for numerical calculation of hydraulic performance of the siphon outlet conduit in a large-scale low-head pumping station, a transparent conduit model experiment method is used to conduct experimental studies on the siphon outlet conduit in the large-scale low-head pumping station in this study. The head loss of the flow through the conduit is measured, and the flow regime in the conduit analyzed. Further, based on the grid-independence analysis, some of the commonly-used turbulence models, including the one-equation turbulence model (S-A turbulence model), two-equation turbulence models (k-ε turbulence model and k-ω turbulence model), and Reynolds Stress turbulence model, are selected to numerically simulate the hydraulic performances of the siphon outlet conduit with three-dimensional (3D) turbulent flow, and the numerical calculation results are compared with the model test results of the conduit. The research results show that the two-equation turbulence model is superior to the one-equation turbulence model and the Reynolds Stress turbulence model in the calculation of the head loss of the siphon outlet conduit. The relative errors of the head loss calculated by the three two-equation turbulence models (i.e. standard k-ε turbulence model, realizable k-ε turbulence model and SST k-ω turbulence model) are less than 3%. Among them, the flow field calculated by the Standard k-ε turbulence model is the most consistent with the model test results.