Parametrical study of thermogravitational diffusion in porous media

This note reports on a numerical study of the thermogravitational diffusion existing in a porous medium saturated with a binary mixture and subjected to a horizontal thermal gradient. It deals with a study of the influence of the dimensionless characteristic parameters on the species separation, using a two-dimensional numerical code based on a spectral method. The existence of a maximum separation ratio corresponding to an optimal Rayleigh number associated to an optimal permeability, is shown. The results are also compared with analytical and experimental results coming from previous works. (C) Academie des Sciences/Elsevier, Paris.