Measurement of Three Dimensional Flow Structure of Droplet Formation Mechanism in T-shaped Junction Using Phase-locked Confocal Micro-piv

This paper aims to investigate a mechanism of microdroplet formation at a micro T-shaped junction using a “phaselocked multicolor confocal micro-PIV (Particle Image Velocimetry)” technique[1]. The multicolor system can measure dynamic behavior of each phase of multiphase flow separately and simultaneously. Additionally, the phase-locking technique enables picking up same condition of droplet formation frequency and translational velocity of droplet to minimize instability of droplet formation phenomenon. The phase-locking technique is necessary to reconstruct three-dimensional flow field from two-dimensional confocal micro-PIV measurement data. We successfully obtained each phase of periodic phenomenon non-invasively by detecting passage of droplet from transmitted light of optical proximity sensor. As a result, three-dimensional flow structure of the droplet formation was successfully reconstructed and the differences in droplet formation mechanisms associated with flow conditions was investigated.