Abstract
When carbon dioxide (CO_2) is injected into the brine, the mixture in a form of CO_2 dissolves into the brine leads to an instability in which CO_2 saturated more-dense brine overlies unsaturated less-dense brine, giving rise to density-driven natural convection. Herein a nonlinear density property fluids system is used to model the convective mixing process. A three-dimensional visualization scheme employing micro-focused X-ray computer tomography (CT) technology is able to obtain the characteristic of the natural convection. The formation and advancement of Rayleigh - Benard fingers induced by density difference can be visualized. The mass transfer increases with the Rayleigh number. The dimensional flux Sherwood number is correlated with Rayleigh number following the power law relationship.
