Abstract
The purpose of this study is to discuss bubble-bubble and bubble wake-wake interactions in a bubble swarm. For this purpose, a bubble-swarm generator that controls the formation and launch of bubbles precisely was employed. Equivalent diameters of the bubbles was about 2.7 mm. The two bubbles were launched side by side and the bubble-bubble distance was 7 mm. The center bubble was launched at the middle of the two leading bubbles 9.75 ms behind the leading bubbles. Using a high speed video camera and PIV, we visualized motion of the bubbles and their surrounding liquid motion. These bubbles linearly ascended during 0.07 sec after launched. An aspect ratio of the center bubble in the time span from 0.02 to 0.07 sec after launched was smaller than those of the leading bubbles. The liquid motion induced by the leading bubbles are considered to enhance dynamic pressure acting on the center bubble.
