混流式转轮中流场的大涡模拟

建立了基于微可压缩流体理论的相对运动的大涡模拟方法,并对混流式转轮流场进行了三维非恒定粘性数值模拟,计算方法采用了有限体积法和预测-校正方法,对固体边壁的处理使用了“壁函数”法。得到了混流式转轮的三维速度场和压力分布,与k-ε模型计算结果进行比较表明,所建立的相对运动的大涡模拟方法对转轮性能预测更加精确、合理,对转轮改型设计具有十分重要的参考价值。

Large eddy simulation of flow through francis turbine runner

A large eddy simulation(LES)approach based on the weakly compressible hydrodynamic equation for the relative motion is developed in a rotational coordinate system,and employed in simulating 3-D flow through a francis turbine runner.The finite volume approach with predictor corrector method and a law of the wall for the solid wall condition are used.The velocity and pressure fields are obtained and compared with the computated results by the k-ε model,showing that the 3-D LES approach can give realistic results of the flow field.