Affiliations: Department of Energy and Environmental Science,
Graduate School of Engineering, Utsunomiya University, 7-1-2 Yoto, Utsunomiya,
Tochigi 321-8585, Japan. E-mail: [email protected] | ASMO Co. Ltd., 90 Umeda, Kosai, Shizuoka 431-0493,
Japan
Abstract: Although the phenomena related to the multiphase flow can be found
in many kinds of industrial and engineering applications, the physical
mechanism of the multiphase flow has not been investigated in detail. The major
reason for the lack of data in the multiphase flow lies in the difficulties in
measuring the flow quantities of the multiple phases simultaneously. Presently,
the visualization and the PIV measurement have been carried out about the both
phases of the liquid-liquid two-phase flow. The difference in the refractive
indices makes the visualization in the vicinity of the boundary of the multiple
phases very difficult. In this study, the refractive index of the aqueous phase
has been equalized to that of the oil phase by adjusting the concentration of
the aqueous solution. As for the surrounding fluid, silicon oil is chosen and
as for the droplet, the aqueous solution of glycerol is prepared whose
refractive index matches that of silicon oil. Both phases are seeded with
neutrally buoyant particles. The droplet is slightly colored with Rhodamine B
so that the position of the invisible droplet can be identified. The difference
in the background brightness in both phases helps PIV algorithm in
distinguishing the motions in each phases. The results show the details of the
flow structures both around and inside of a falling droplet simultaneously.
Keywords: Visualization, PIV, Index matching, Droplet, Two-phase flow