Theresa Kurz (SRP NUPUS Scholarship Holder 2017)

Title of Master's thesis: Implementation and investigation of different coupling schemes for hybrid-dimensional models in DuMux

Supervisors: Kilian Weishaupt (M. Sc.), Rainer Helmig

Description: Coupling of different model domains or processes in porous media is an important tool for simulating complex flow and transport processes within permeable media. By coupling different domains, interactions between porous medium and free flow can be investigated, which apply in modelling different evaporation processes e.g. from soil or construction material. Further different porous media models of mixed dimensionality can be combined. Regions of high interest with a great degree of process activity may be accounted for in ample detail, e.g. by employing a so-called pore-network model that efficiently resolves pore-scale phenomena using a network of one-dimensional entities. The remaining parts of the potentially rather large entire computational domain can then be covered by well-established REV-scale ap-proaches such as Darcy’s law.

Furthermore the coupling of porous media flow and chemical reaction processes within the porous structures is important for many applications. In the consideration of solute transport, flow processes and chemical reactions mutually influence each other. The distribution of solute concentration depends on the flow whereas the flow depends on the porous structure which can change due to precipitation of the solute. These processes are relevant e.g. for salt precipitation in the subsurface or the degradation of cement exposed to CO2 .

This thesis aims at implementing and investigating different coupling schemes. For the coupling of a pore-network model with a free flow and Darcy domain, a sequential approach is implemented and compared with the existing fully monolithic one. Also reactive transport is implemented in the pore network model, upon which the coupling of chemical reaction and flow processes is examined.