Experimental observations and theoretical studies on solidification processes in saline solutions

A detailed study is presented with experimental and theoretical parts on the transition from a planar solid-liquid interface to a cellular structure during a transient solidification process in a saline solution. A new experimental system that facilitates control over the freezing process, continuous tracking of the solid-liquid interface, and accurate evaluation of the temperature distribution on the interface is described. Experimental results are shown, including photographs of the solid-liquid interface instability and the transition from a planar interface to a cellular structure. A numerical technique that combines experimental data with “front-tracking” finite-element analysis is introduced. It is shown that the numerical results correlate well with the experimental observations. Incorporating the numerical results in the Mullins-Sekerka stability criterion leads to good predictions of the onset of the freezing interface instability during transient solidification in a saline solution.