【摘要】 基于三维时均N-S方程对水轮机内部流动及特性进行三维数值模拟分析,首先采用标准k-ε模型在不同导叶开度工况下对水轮机进行了全流道多部件、动静耦合的定常湍流计算,获得了各工况下各过流部件内及动静部件间的流场,并预测了水轮机的能量和空化性能。在定常湍流计算的基础上,以其作为初始条件应用RNG k-ε模型和滑移网格技术进行了水轮机动静干扰的非定常湍流数值模拟,得到了更合理的流场分布结果。该研究对于深入了解水轮机流激振动的内在机理、改善水轮机的综合性能、提高水轮发电机组的运行稳定性具有参考价值。更多还原

【Abstract】 Numerical simulation of the steady and unsteady flows in the whole flow passage of a Francis hydro-turbine based upon the Reynolds averaged Navier-Stokes equations was conducted. The steady turbulent flow simulation of the whole flow passage multi-compents and dynamic-static compling were calculated in different opening cases of the moving guide vanes with the standard k-ε model,swirling flow and its developing of the flows in the turbine under different conditions were obtained. The efficiency and cavitation performances were predicted quantitatively. The simulation of the unsteady flows was conducted on the RNG k-ε model. The steady flows simulated were used as the initial flows of the unsteady simulations,in which the sliding mesh technique was employed and reasonable conclusion of the flow field distribution was acquired. The results show the understandings of the intrinsic vibrating mechanism of a hydro-turbine due to the excitation by the flows,and are helpful to improve the comprehensive hydraulic performances and to enhance the operating stability of a machinery set.更多还原