Numerical study of breakup and solidification of a liquid column

Abstract

Liquid columns appear in many engineering problems. Such a liquid column held vertically between two rods and undergoing the solidification process is the focus of the present study. The investigation is conducted using an axisymmetric front-tracking method. Starting with an initial cylindrical shape, gravity causes the liquid to accumulate in the bottom of the column, leading to a thinner upper part and a wider lower part with the formation of a neck near the mid-plane of the column. As solidification initiates from the rod ends, this behavior of the column is imprinted. The neck size can further decrease and reach zero, leading to the breakup of the column during solidification. After breakup, the upper part quickly reaches the final solidified state while the solidification of the lower part takes longer. To prevent breakup, we can increase the solidification rate by raising the Stefan number. Additionally, increasing the Ohnesorge number, decreasing the Bond number, or reducing the length of the column also prevents the column from breaking up. The regime diagrams, showing the transition between breakup and non-breakup in the solidification of the column, are also proposed.