摘要
为有效模拟桥梁结构的高雷诺数绕流及拓展格子玻尔兹曼方法(lattice Boltzmann method,LBM)在桥梁抗风中的应用,将动态Smagorinsky亚格子涡黏性模型嵌入到多松弛时间格式的LBM中。在LBM中,亚格子涡黏性通过网格滤波和检验滤波两次滤波求得,网格滤波以LBM的格子网格为滤波尺度由LBM的局部非平衡矩直接完成,检验滤波在更大尺度上采用有限差分求解。利用亚格子涡黏性修正LBM的运动黏性,构造了一种可以模拟钝体高雷诺数绕流的LBM大涡模拟方法即MRT-LBM-DSM。采用MRT-LBM-DSM结合LBM的移动边界技术对苏通大桥主梁断面的静力三分力系数和气动导数进行了仿真计算。研究证明,MRT-LBM-DSM可以准确预测湍流流动,可用于桥梁主梁断面的高雷诺数绕流仿真和计算主梁断面的气动参数。
For simulating high Reynolds flows around bridge decks effectively, as well as expanding the application of the lattice Bohz- mann method (LBM) in bridge wind resistance, dynamic Smagorinsky sub-grid-scale model was embedded into the multiple relaxation times (MRT) formulation of LBM. The subgrid eddy viscosity can be obtained from performing discrete filtering operations at lattice grid and test-filter levels. Grid filter was locally calculated by means of non-equilibrium moments of the MRT-LBM, while test filter was computed by finite difference method at a larger scale. A MRT-LBM-DSM method, which can simulate high Reynolds flows effectively, was constructed through modifying the kinematic viscosity of the MRT-LBM by incorporating subgrid eddy viscosity. As an example, the Sutong bridge was investigated to calculate its static force coefficients and aerodynamic derivatives. The comparison between simulation and experimental results showed that the present method gives much better prediction of turbulent flows, and can be used for simulating high Reynolds flows around bridge decks and calculating aerodynamic parameters.
出处
《四川大学学报(工程科学版)》
EI
CAS
CSCD
北大核心
2013年第6期87-95,共9页
Journal of Sichuan University (Engineering Science Edition)
基金
国家国际科技合作项目(2011DFA21460)
国家高技术研究发展计划资助项目(2008AA11Z104)