In this work, a new discretization approach for coupled free and porous-medium flows is introduced, which uses a finite volume staggered-grid method for the discretization of the Navier-Stokes equations in the free-flow subdomain, while a vertex-centered finite volume method is used in the porous-medium flow domain. The latter allows for the use of unstructured grids in the porous-medium subdomain, and the presented method is capable of handling non-matching grids at the interface. In addition, the accurate evaluation of coupling terms and of additional nonlinear velocity-dependent terms in the porous medium is ensured by the use of basis functions and by having degrees of freedom naturally located at the interface. The available advantages of this coupling method are investigated in a series of tests: a convergence test for various grid types, an evaluation of the implementation of coupling conditions, and an example using the velocity dependent Forchheimer term in the porous-medium subdomain.
翻译:在这项工作中,对互通自由和多孔的中文本流采用了一种新的分解方法,在自由流次场外对纳维耶-斯托克斯方程式的分解使用量定的错开格-格格方法,而在多孔中文本流域则使用顶点偏向的量定法,后者允许在多孔中文本次场内使用无结构的网格,而且所提出的方法能够处理界面上的非对接网格;此外,通过使用基础功能和在界面上自然定位自由度,确保准确评价多孔介质介质中的混合条件和额外非线性速度依赖条件。