Abstract
The double diffusive convection during the freezing or melting in aqueous solution was numerically studied at the Prandtl number Pr=13.4, the Lewis number Le=100, the buoyancy ratio N0=0,1, 5 or 10 and the Rayleigh number Ra0=105 or 107. In the case of freezing, a thin boundary layer of concentration was formed near the moving boundary and the solute was accumulated near the bottom of the vessel. In the case of melting, one or two thermal convection roll cells were formed at N0=0 (Ra0=105 and 107), multi-layered roll cells at N0=1 to 5 (Ra0=107) and a concentration stratified layer at N0≥1(Ra0=105) or at N0=10 (Ra0=107). The melting of ice in a solution became strong for the lower part of moving boundary owing to the solutal convection near the ice.
