三种κ-ε模型模拟混流式水轮机转轮叶片湍流场差异性比较

Comparison of Numerical Simulation of Hydraulic Turbine with Three Different κ-ε Models

为比较Standardκ-ε模型、RNGκ-ε模型、Realizableκ-ε模型用于水轮机数值模拟时的异同,采用三种κ-ε模型对不同工况下带有副叶片的混流式水轮机转轮进行了三维定常湍流数值模拟,流场求解使用分离式解法,压力场求解使用SIMPLEC算法。结果表明,三种κ-ε模型用于水轮机的数值模拟具有一定的准确性和适用性,在相同模拟条件下都可得出与实际流态大致吻合的结果,但在计算量、捕捉流动细节及计算精度等方面存在差异,可为水轮机数值模拟研究中κ-ε模型的选择提供参考和依据。

To compare the similarities and differences of three κ-ε models for numerical simulation of hydraulic turbine, three-dimensional steady turbulent flow under different operating conditions for Francis turbine with half vanes is simulated by using standard κ-ε model, RNG κ-ε model, realizable κ-ε model. The separated method is used to solve the flow field and S1MPLEC algorithms is used to solve the pressure field. The computational results show that three kinds of κ-ε models have a certain accuracy and applicability when they are applied to numerical simulation of hydraulic turbine; the calculation results of three models under same simulation conditions are generally consistent with the actual flow state, but there are some differences in terms of the convergence speed, the amount of computation and the accuracy of capturing the details of the flow. So, it can provide reference and basis for selection of κ-ε model in numerical simulation study of hydraulic turbine.