An understanding of the flow and transport processes occurring at the interface and between porous medium and turbulent free-flow domains is necessary in a wide range of industrial and environmental applications. The flow dynamics in each of these domains exhibit a strong coupling to the other, where the coupling often depends on characteristics of the interface. In order to evaluate these coupled processes, an understanding of the underlying flow concepts is imperative. In this work, the effects of turbulence, interface roughness, non-isothermal, and compositional flow dynamics are all investigated at the REV scale using coupled free-flow porous media flow models. The developed concepts are paired with results from experiments at multiple scales with various backgrounds.