Geometrical Effects of an Entrapped Bubble on Pore Shape in Solid

The shape of a pore which results from a bubble entrapped by a solidification front is predicted in this work. Pore formation and its shape in solid influence not only microstructure of materials, but also contemporary issues of various sciences of biology, engineering, foods, geophysics and climate change, etc. This work extends previous models by accounting for realistic mass, momentum and energy transport across a self-consistently determined shape of the bubble cap beyond the solidification front. Accurate determination of contact angle from a realistic shape of the cap is required to predict the relevant shape of the pore in solid. The results shows that an increase in Bond number and decrease in initial contact angle decrease radius and length of the pore and time for bubble entrapment. The predicted growth and entrapment of a tiny bubble as a pore in solid are found to agree with experimental data. A realistic prediction and control of the pore shape in solid has therefore been obtained.