Drops on a free-flow/porous-medium-flow interface have a strong influence on the exchange of mass, momentum and energy between the two macroscopic flow regimes. Modeling droplet-related pore-scale processes in a macro-scale context is challenging due to the scale gap, but might be rewarding due to relatively low computational costs. We develop a three-domain approach to model drop formation, growth, detachment and film flow in a lower-dimensional interface domain. A simple upscaling technique allows to compute the drop-covered interface area fraction which affects the coupling fluxes. In a first scenario, only drop formation, growth and detachment are taken into account. Then, spreading and merging due to lateral fluxes are considered as well. The simulation results show that the impact of these droplet-related processes can be captured. However, extensions are necessary to represent the influence on the free flow more precisely.

自由流动/多孔介质流动界面上的液滴对两种宏观流动形式之间的质量，动量和能量交换有很大的影响。由于尺度差异，在宏观尺度上对与液滴相关的孔隙尺度过程进行建模具有挑战性，但由于计算成本相对较低，因此可能会有所收获。我们开发了一种三域方法来模拟低维界面域中的液滴形成，生长，分离和膜流动。一种简单的放大技术可以计算影响耦合通量的液滴覆盖界面面积分数。在第一种情况下，仅考虑液滴的形成，增长和脱离。然后，还要考虑由于横向通量引起的扩散和合并。仿真结果表明，这些液滴相关过程的影响可以被捕获。然而，