In models concerning coupled free-flow and porous-medium flow, the different behavior of the two flow regimes typically results in an unbalanced system of equations. As a result, a fully coupled system often becomes computationally expensive, sometimes even infeasible, to solve in a monolithic manner.
The main objective of this project is to develop and analyse efficient solution methods for coupled free-flow porous-media flow problems based on iterative decoupling strategies, implement the proposed methods numerically in a unified software framework, and extend the approaches to related, more complex flow problems. Two extensions have a central focus within this project, namely the adaptation to multi-rate time stepping and generalizations to non-linear
problems. These non-linear extensions include using the Navier-Stokes equations in the free flow domain and introducing multi-phase flow to the system.