UNSTEADY PHENOMENA IN THE DOUBLE-DIFFUSIVE CONVECTION FLOWS AT HIGH RAYLEIGH NUMBER

A two-dimensional dual-mesh hybrid numerical method is used to investigate some small scale phenomena in double-diffusive convection flows at high Rayleigh number. With a horizontal temperature gradient, the interface of the two-layer stratified system becomes tilted and wavy, resulting in two typical flow patterns. The quasi-steady flow pattern is scattered with abundant salt fingers and hook-like plumes, which agree well with experimental data available in the literature qualitatively. It is found that three-dimensional modeling should be carried out in order to have better agreement with experimental data. In addition, the stratified system is found to be sensitive to the buoyancy ratio.