Double Diffusive Convection during Solidification at a Vertical Wall
Transient solidification of a confined volume of a homogeneous binary solution at vertical wall produces horizontal gradients of solute concentration and temperature in the liquid. For solutions in which the density varies with the concentration of both of these properties, the potential exists for a double-diffusive (thermosolutal) convective flow to develop in the vicinity of the solidification front. The boundary layer motion contributes to the establishment of a vertical density (compositional and thermal) stratification of the liquid in the interior of the enclosure, and the subsequent onset of double-diffusive layering. A mathematical model is developed to describe the time-dependent solidification process and double-diffusive interactions in the liquid phase. Preliminary results of the calculations are compared to experimental observations of the solidification behavior of aqueous sodium carbonate solutions with initial compositions on both sides of the eutectic.
KeywordsRayleigh Number Convection Cell Thermohaline Convection Cellular Convection Aqueous Sodium Carbonate Solution
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