CFD模拟方法的发展成就与展望

ON THE ACHIEVEMENTS AND PROSPECTS FOR THE METHODS OF COMPUTATIONAL FLUID DYNAMICS

本文综述了计算流体力学(computational fluid dynamics,CFD),尤其是计算空气动力学的发展概况.从计算方法、网格技术、湍流模型、大涡模拟等方面分别总结了CFD所取得的成就,分析了当前存在的问题、困惑,展望了其发展趋势.在CFD计算方法中,主要介绍了中心格式、迎风格式、TVD格式、WENO格式、紧致格式以及间断Galerkin有限元方法,对不同方法的原理和特性进行了系统阐述.网格技术包括结构网格、非结构网格、混合网格以及重叠网格,重点讨论了重叠网格的若干关键技术.在湍流模型中,对目前的模型进行分类介绍,包括线性涡黏性模型、二阶矩模型、非线性模型等,还介绍了转捩模型、DES方法以及SAS方法等.在大涡模拟方法中,就其中若干相关的研究方向进行了探讨,包括滤波方法、亚格子模型、收敛标准、数值格式等.文中还包含了作者在相关领域的若干研究成果.

Methods of computational fluid dynamic are summarized, especially for computational gasdynameis. The achievements of CFD are reviewed, including numerical schemes, grid techniques, turbulence modeling and large eddy simulation, whose problems and prospects are presented as well. For numerical schemes, several representative methods are analyzed in terms of performances and principles, including central schemes, upwind schemes, TVD schemes, WENO schemes, compact difference schemes and discontinuous Galerkin methods. For grid techniques, some typical methods are elucidated, including structured grids, unstructured grids, hybrid grids and chimera grids. Several key techniques about chimera grids are emphasized. In the section of turbulence modeling, various turbulence models are categorized including linear eddy viscosity models, second-order moment models, nonlinear eddy viscosity models, as well as transition models, DES and SAS. In regard to large eddy simulation, some relevant research areas are discussed, such as filtering methods, sub-grid models, convergence standards and numerical schemes. Besides, some investigations and examples by the authors are included as well.