Thermal convection and dispersion in folded gaps embedded in impervious rocks

It is presented a numerical and experimental study related to thermal convection and Taylor dispersion in a symmetrical folded gap of small aspect ratio. The gap is surrounded by an impervious rock which is affected by a constant vertical temperature gradient. Two cases were analyzed, the fluid-filled gap and the fluid-saturated porous layer. Their corresponding convective flows were calculated for small Rayleigh number regimes. Taylor dispersion of a passive contaminant, in both cases, was studied. It was found that dispersion is strongly limited by the convective flows. Indeed, the Peclet number and the gap aspect ratio seem to be tight related to an eventually limited dispersive transport rate.