ABSTRACT
The use of computers over the last 60 years for simulating subsurface “ow problems has provided an impressive, ever-expanding ability to model processes at a high resolution. Whereas in the 1960s a computational grid with 500 œxed nodes would have pushed the boundaries of computer power [59], simulations today involve millions of spatial grid points and adaptive meshes [40,57]. The availability of this power for solving equations that purport to describe physical and chemical processes in porous media is wasted, however, if the equations being used to describe
1.1 Introduction ..............................................................................................................................3 1.2 Overview ...................................................................................................................................5 1.3 Theory .......................................................................................................................................6
