摘要
基于三维瞬态N-S方程,采用大涡模拟方法中的Smargorinsky模型,应用模拟动静干扰效果较好的滑移网格技术,以标准k-ε模型稳态计算的结果作为初始条件,对某混流式水轮机全流道进行了的三维瞬态湍流数值模拟.用Fluent 6.3,采用非结构化的混合网格和压力速度耦合的PISO算法,成功地模拟了水轮机在运行中的各种瞬态细节过程,如涡旋的卷起、增长、合并、破碎和脱落.模拟结果给出了偏工况下水轮机导水机构和转轮流道内大尺度涡结构的瞬态发展演变过程.计算结果表明大涡模拟方法能较好地模拟水轮机内水流的瞬态流动特性和瞬时涡的发展演化过程,该方法可为探索研究水力机械复杂流道湍流运动状态下涡旋的形成机理提供有价值的参考.
Numerical simulation of three-dimensional transient turbulent flow in the whole flow passage of a Francis turbine based upon the Reynolds averaged N-S equations was conducted with the large eddy simulation（LES） technique on Smargorinsky model and sliding mesh technology.The steady flow data simulated with the standard k-ε model were used as the initial conditions for the unsteady simulation.The large scale structures evolving in spatially and temporally were visualized by the software Fluent 6.3,using unstructured hybrid-grid and PISO algorithm.The evolution details of the large scale structures such as eddy from generate to shedding in vane cascades and blade passages were well captured at special case.The results show that LES can well simulate transient turbulent flow in a Francis turbine with complex geometry.The computational method provides some reference for exploring mechanism of eddy formation in a complex turbulent of hydraulic machinery.
出处
《排灌机械工程学报》
EI
2010年第6期502-505,共4页
Journal of Drainage and Irrigation Machinery Engineering
基金
国家自然科学基金重点资助项目(50839003)
云南省自然科学基金资助项目(2008GA027)
