Abstract
An experimental study of solidification is performed for a hypoeutectic sodium nitrate solution in a confined rectangular vessel with varying initial concentration. The experiments have been conducted by heating the lower wall of the vessel and cooling the vertical cylinder. We investigate the development of its temperature and concentration distribution in the liquid region during the solidification and its effect on the solid layer thickness formed around the cylinder. The growth of the solid layer, which accompanies solute ejection to liquid region, leads to double-diffusive convection and form a sharp density interface. Across the interface a drastic change of temperature and concentration is observed. Therefore, the solid layer thickness undergoes a dramatic change when the interface passes.