动网格在非饱和饱和界面数值模拟中的应用研究进展

为了探讨结构和非结构动网格技术在地下水非饱和-饱和数值模拟领域未来的发展趋势, 总结了非饱和-饱和耦合数值模拟研究现状, 介绍了动网格技术原理及运动边界结构和非结构网格的变形方法, 综述了动网格技术在非饱和-饱和分界面的应用现状及存在的不足, 探讨了相关研究的未来发展趋势。综合分析表明: 结构动网格和非结构动网格均存在其固有优缺点, 结构、非结构混合网格以及多种动边界处理方法的结合使用在非饱和-饱和耦合数值模拟研究中具有重要的应用价值。在模拟潜水面的变动时, 可将多种网格变形方法结合使用, 当潜水面位置和形状变动较小时, 采用弹簧法更新网格; 当潜水面位置变化较大但形状变化较小时, 采用重叠结构动网格技术或铺层法更新网格; 当潜水面形状变动较大时, 则采用网格重构法更新网格, 从而更精确地模拟非饱和-饱和分界面的变化和移动。相关研究为场地非饱和带土壤与饱和带地下水协同防治工作提供了科学指导。 

Research progress on the application of dynamic grids in the numerical simulation of unsaturated-saturated interfaces

In order to discuss the future development trend of structural and unstructured dynamic grid technology in the field of unsaturated-saturated groundwater numerical simulation, this paper summarizes the research status of unsaturated-saturated coupled numerical simulation, introduces the principle of dynamic grid technology and the deformation method of moving boundary structure and unstructured grid, summarizes the application status and shortcomings of dynamic grid technology in the unsaturated-saturated interface, and discusses the future development trend of related research. The review shows that both structural dynamic grids and unstructured dynamic grids have their inherent advantages and disadvantages, and the combination of structural/unstructured hybrid grids and multiple dynamic boundary treatment methods has important application value in the research of unsaturated-saturated coupling numerical simulation. When simulating the change of phreatic surface, a variety of mesh deformation methods can be combined. When the change of the position and shape of the phreatic surface is small, the spring method is used to update the mesh; When the position of the water table changes significantly but the shape changes little, the overlapping structure dynamic grid technology or the overlay method is used to update the grid; If the shape of the water table changes greatly, the grid reconstruction method is used to update the grid, so as to more accurately simulate the change and movement of the unsaturated-saturated interface. Relevant research provides scientific guidance for the coordinated prevention and control of unsaturated zone soil and saturated zone groundwater of the site.