Abstract
Flows in porous media can exhibit steady, time-dependent, chaotic and turbulent behaviors, despite the highly dissipative effects of viscosity and thermal conductivity. The phenomena intrinsic to porous media are brought about by the presence of porous matrix, basically through the short distance interaction of fluid with the adjacent inner walls, which exist everywhere in porous media. To describe such microscopic effects in porous media, proper averaging techniques are needed, taking characteristic length scales into consideration. Particularly, a discussion is made on the nature of Forchheimer resistance in close relevance with turbulent dissipation in porous media, concentrating on the roles of large-scale and small-scale vortices. Discussions are also made on recent turbulence models. It is hoped that future studies reexamine the macroscopic governing equations, considering microscopic and unsteady nature of the chaotic and turbulent behaviors.
