Host: The Japan Society of Mechanical Engineers
Name : [in Japanese]
Date : November 29, 2018 - November 30, 2018
Spherical bubbles rising along an inclined flat wall has been investigated experimentally to analyze the bubble-bubble interaction and the clustering behavior. In this study, free-slip and no-slip conditions on the bubble surface are controlled using MgSO4 solution and TritonX-100 solution, respectively. The bubble-bubble interaction at a bubble Reynolds number of 100 and the effect of boundary condition are discussed through the quantitative evaluation of the bubble velocities and the distance between two bubbles. It is observed that the bubbles tend to be arranged in horizontal line as they rise. First, the trailing bubble is accelerated under the influence of the wake of the leading bubble. Then, the trailing bubble moves around the leading bubble, and two bubbles take side-by-side arrangement. This interaction does not depend on the boundary condition on the bubble surface qualitatively. The quantitative differences due to the boundary condition especially appear in the faster rising velocity of the trailing bubble and longer distance between side-by-side arranged bubbles in case of no-slip bubbles. The velocity of the bubble cluster is also analyzed.
