EXTENDED IRREVERSIBLE THERMODYNAMICS AS A FRAMEWORK FOR TRANSPORT PHENOMENA IN POROUS-MEDIA

A theoretical extended thermodynamic approach to describe transport in porous media is presented. For a particular model of the porous medium, approximate time evolution equations for the fluxes in the system are derived. The use of these equations is illustrated by considering three different transport problems. A finite velocity for the propagation of thermal disturbances within the medium is predicted in the case of heat transport in a system where the effective porosity is zero. Also, a generalization of the Darcy-Brinkman law that incorporates thermal effects, independently of the presence of external forces, arises when consideration is given to the combined mass and heat transport problem. Finally, for the isothermal transport of fluid, the thermodynamic framework provides a possible interpretation of the origin and the role played by both the Brinkman and the Forchheimer corrections to Darcy's law.