Numerical Simulation of Natural Convection in an Inclined Square Cavity (original) (raw)

In this paper we investigate the mass transfer of CO 2 injected into a homogenous (sub)-surface porous formation saturated with a liquid. In almost all cases of practical interest CO 2 is present on top of the liquid. Therefore, we perform our analysis to a porous medium that is impermeable from sides and that is exposed to CO 2 at the top. For this configuration density-driven natural convection enhances the mass transfer rate of CO 2 into the initially stagnant liquid. The analysis is done numerically using mass and momentum conservation laws and diffusion of CO 2 into the liquid. The effects of aspect ratio and the Rayleigh number, which is dependent on the characteristics of the porous medium and fluid properties, are studied. This configuration leads to an unstable flow process. Numerical computations do not show natural convection effects for homogeneous initial conditions. Therefore a sinusoidal perturbation is added for the initial top boundary condition. It is found that the mass transfer increases and concentration front moves faster with increasing Rayleigh number. The results of this paper have implications in enhanced oil recovery and CO 2 sequestration in aquifers.