テイラークエット気泡流の時空間トポロジー

抄録

Injection of bubbles into Taylor–Couette flow creates new flow modes that do not appear in single-phase flow conditions. A spiral vortical array is one such mode departing from the original toroidal Taylor vortices. The aim of the present study was to explore the mode transition of the two-phase flow using particle tracking velocimetry. Vertical-axis concentric cylinders with a rotating inner cylinder were used to measure the motion of both phases in the range 300 < Re < 5000. From time–space mapping of the experimentally measured stream functions, we found that bubble injection amplified the axial displacement of the wavy Taylor vortices in the toroidal array, and there was a smooth switch to a spiral array when the azimuthal travelling velocities coincided. During this vortical reconnection, we found that the two counter-rotating vortices were attenuated asymmetrically.