Visualization and investigation of natural convection flow of CO2 in aqueous and oleic systems

The experiments show that natural convection currents are weakest in highly concentrated brine (25 w/w% NaCl solution) and strongest in oil, due to the higher and lower density contrasts respectively. Therefore, the set-up can screen aqueous salt solutions or oil for the relative importance of natural convection flows. The Schlieren pattern consists of a dark region near the equator and a lighter region below it. The dark region indicates a region where the refractive index increases downward, either due to the presence of a gas liquid interface, or due to the thin diffusion layer. The experiments demonstrate the initiation and development of the gravity induced fingers.