BUOYANCY-DRIVEN ACCELERATED MOTION OF AN ENCAPSULATED LIQUID-DROP

The buoyancy-driven motion of an encapsulated liquid drop in liquid-li quid-gas systems was analyzed experimentally and theoretically. To inv estigate the accelerated motion of the encapsulated drop in detail, an optical measuring device for the local upward velocity was designed. Furthermore, a simplified effective theory based on the experimental d ata was proposed for the rectilinear accelerated motion of the spheric al encapsulated drop produced from the compound jet in the systems. Th e effects of drop radius and liquid physical properties on the acceler ated motion were clarified numerically. The drag components, which wer e composed of the steady drag term, the added mass term and the Basset history integral term, were also analyzed. The numerical results of t he upward velocity quantitatively agreed with the experimental results in the range of intermediate Reynolds numbers; Re approximately O(100 ).