Coupled free-flow and porous-medium systems appear in a variety of industrial and environmental applications. Fluid flow in the free-flow domain is typically described by the (Navier–)Stokes equations while Darcy’s law is applied in the porous medium. The correct choice of coupling conditions on the fluid–porous interface is crucial for accurate numerical simulations of coupled problems. We found out that the Beavers–Joseph interface condition, which is widely used not only for fluid flow parallel to the porous layer but also for filtration problems, is unsuitable for arbitrary flow directions. To validate our statement, we provide several examples and compare numerical simulation results for the coupled Stokes–Darcy problems to the pore-scale resolved models. We show also that the Beavers–Joseph parameter cannot be fitted for arbitrary flow directions.

中文翻译：

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Beavers-Joseph 界面条件不适用于过滤问题

耦合的自由流动和多孔介质系统出现在各种工业和环境应用中。自由流动域中的流体流动通常由 (Navier–)Stokes 方程描述，而 Darcy 定律适用于多孔介质。流体-多孔界面耦合条件的正确选择对于耦合问题的精确数值模拟至关重要。我们发现 Beavers-Joseph 界面条件不仅广泛用于平行于多孔层的流体流动，也用于过滤问题，不适用于任意流动方向。为了验证我们的陈述，我们提供了几个例子，并将耦合 Stokes-Darcy 问题的数值模拟结果与孔隙尺度解析模型进行了比较。