Controlling bubbles position during the ice formation process

Abstract It is significantly important to make transparent ice blocks or design the microstructure of ice by understanding the mechanism of bubble formation during the ice formation process. A theoretical model has been established to relate the thickness of the bubble-free segment and the solidification rate. A series of ice formation experiments have been done with different solidification rates. The critical saturation ratio of industrial distilled water is calculated as 11.65 by the theoretical model, which is slightly smaller, by measuring the thickness of the bubble-free segment and solidification rate. The explicit expression of bubble-free distance agrees well with the experimental results and numerical solutions. Completely transparent ice blocks are made by controlling the solidification rate guided by the model. It helps to understand the reason why a layered pouring method can increase efficiency.