Modeling and analysis of the movement of fluid-fluid interfaces ín porous media coupled with free flow

点击翻译按钮获取中文摘要

In this subproject, we focus on the modeling and interpretation of evaporation from porous media under the influence of atmospheric processes, such as wind and radiation. Within the first project phase, we have developed an REV-scale model concept which allows the coupling of a laminar single-phase free flow and a two-phase porous-medium flow under non-isothermal, compositional flow conditions. An important goal is to extend this concept for turbulent flow conditions in the atmospheric part of the model domain and to include further processes like radiation and infiltration. In this context, different kinds of interfaces may have a strong impact on the transfer fluxes and have to be considered: Fluid-fluid interfaces, interfaces between different porous materials and the interface between unsaturated soil and atmosphere. The vision is to develop a model which can reproduce the complex interaction at these interfaces in detail and which allows the simulation and analysis of sequences of infiltration and evaporation. In this context, the effects of hysteresis at heterogeneous structures and of dynamic capillary pressure on the transfer fluxes and the fluid front evolution will be explored. The model will allow to determine and extend the limits of common state-of-the-art models and to improve the predictability of evaporation rates. Furthermore, different scenarios will be analyzed with respect to the required model complexity aiming at a model reduction and an improved modeling on the field scale.