基于动网格的活动导叶流道内湍流场数值模拟

基于任意拉格朗日欧拉框架下的二维时均N-S方程,应用非结构动网格技术,对某型号混流式水轮机活动导叶单流道内的导水机构关闭过程,进行了动态湍流数值模拟.利用CFD软件Fluent 6.3,采用非结构化三角形网格,标准k-ε湍流模型和压力速度耦合的PISO算法,真实地模拟了导水机构关闭的动态过程中,活动导叶流道内的压力场和速度场的瞬态变化过程.数值计算结果表明,导水机构两段折线关闭过程中,随着活动导叶开度的减小,流场发展呈现明显的非定常特性,水流绕过活动导叶后出现强的旋涡,对过渡过程的动态特性产生了影响.该方法能有效地模拟由于活动导叶动作诱发的流场脉动.

Numerical simulation of turbulent flow in vane passage based on dynamical mesh technology

The numerical simulation of two dimensional transient turbulent flow in a guide vane passage of a Francis turbine was conducted based on the ALE（Arbitrary Lagrangian-Eulerian） and dynamic mesh technology.The dynamical changes of the pressure and velocity were simulated by Fluent 6.3,using unstructured-triangle grid,standard k-ε turbulence model and PISO algorithm as the guide vane was mo-ving.The results show that the evolution of the flow field is unsteady with decreasing of the vane opening.Based on these researches,the eddy structures evolving spatially and temporally were visualized.The calculation provides some reference for vortex-induced vibration in a complex turbulent flow of hydraulic machinery.The study is valuable for simulating the turbulence induced by the guide vane adjustment.