The research in this proposed Collaborative Research Centre (Sonderforschungsbereich SFB) aims to acquire the much-needed fundamental understanding of how interfaces affect flow, transport and deformation processes in porous-media systems. This will involve the challenging tasks of quantifying how the dynamics of fluid-fluid and fluid-solid interfaces in porous-media systems are affected by pore geometry, heterogeneity and fractures, and of developing mathematical and computational models that describe the effective behaviour of porous-media systems including the effects of interfaces that occur on much smaller spatial scales.
Flow, transport and deformation in porous media are highly coupled processes that strongly depend on the non-linear interplay between physical, chemical and biological phenomena. According to the current state of the art, the analysis of these processes is mostly carried out on a variety of characteristic spatial and temporal scales that are determined by the geometry, structure and heterogeneity of the porous media. However, it is increasingly being recognised that the relevant overall functioning of porous-media systems is dictated by the character, geometry and dynamics of various types of fluid-fluid and fluid-solid interfaces that occur not only on the characteristic scales but most notably on smaller scales. For this reason, many available model concepts do not adequately capture and predict the actual system behaviour. Examples for this lack of predictive ability include the extended Darcy’s law for multi-phase flow, current models for evaporation from porous media, and existing models for fracture/damage propagation in porous media.
The relevance of the research of SFB 1313 is especially pronounced in complex coupled processes such as infiltration, multi-phase flow, evaporation from porous media, chemical reactions that change the pore structure, deposition of solids within the pore space and fracture propagation through porous media.
Examples for such complex interfacial processes are the flow of organic liquids in contaminated soils; the storage of ''green'' gas (methane or hydrogen from renewable sources via power-to-gas), the flow of complex fluids in biological tissues; or the melting and metamorphism of snow.
In technical systems examples are the drying of paper pulp; the absorption of liquids in nappies or in super-absorbent polymers; gas and water transport in fuel cells; the drying of foods and building materials; or thermo-chemical energy storage.
In order to focus research efforts within SFB 1313, four projects areas have been defined that are representative of a wide range of interface-driven processes in porous media.
- Project Area A: Complex interface-dependent exchange processes (mass, momentum and energy) for coupled free-flow/porous-media systems.
- Project Area B: Complex fracture and damage processes in fluid-filled porous media.
- Project Area C: Pore-space alterations due to interacting processes at the interface between the fluid and the solid phase.
- Project Area D: Work in the aforementioned project areas will involve a coordinated research effort that combines mathematical and computational model development with advanced multi-scale imaging-based experiments. Project Areas A to C share many conceptual challenges, such as the visualization of both simulation and experimental results, the definition of benchmarks for code and model validation, as well as the coupling of different multi-physics and multi-scale simulation environments.