Visualization of a Limit Cycle Orbit in a Taylor Vortex Flow with a Short Annulus

Abstract

The purpose of the present study is to experimentally visualize the limit cycle orbit, which has previously only been confirmed numerically in multi-phased Taylor vortex flow (TVF). In the limit cycle, solid particles are gathered in a very limited orbit line. While this phenomenon is unique and does not occur in the general flow region, it is useful for analyzing the anti-plugging characteristics in industrial rotating filter devices. The limit cycle orbit is formed around the central region of each vortex cell as a closed toroidal curvature. In each vortex cell, solid particles approach the limit cycle orbit with time due to the interaction of forces that occurs between fluids and particles. In the present study, experimental visualization of the limit cycle orbit is performed using a TVF device with a short annulus, which has a unique self-excited oscillation mode and could be applied to gentler and more efficient mixing reactors. This orbit appears to be strongly related to the isolated mixing regions, which have been studied previously, that form mainly in the central region of the vortex cell. In addition, we discuss the relationship between the limit cycle orbit and the isolated mixing regions.